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Normal A/C on / off cycle durations?
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glynndaddy
Jul 17, 2006, 1:13:23 AM7/17/06
to
Is there a general rule-of-thumb for how long an air conditioner should
run and how long it should stay off? I realize this probably depends
on a variety of variables, but is there a rule-of-thumb. I've searched
quite a bit and can not seem to find an answer.
run and how long it should stay off? I realize this probably depends
on a variety of variables, but is there a rule-of-thumb. I've searched
quite a bit and can not seem to find an answer.
If it helps, my house is 1 story, 2400 sq ft. I have the thermostat
set at 78. It is 85 degrees outside, humidy 72%.
Right now, my a/c stays on for 8 - 10 minutes and goes off for 7 - 9
minutes.
Thanks for your help.
udarrell
Jul 17, 2006, 10:31:08 AM7/17/06
to
glynndaddy wrote:
At those temps and TSTAT setting the unit is short cycling!
Each time it starts a run cycle it takes nearly 5 minutes to reach its
optimal cooling capacity at those temps and humidity levels.
Where is the RM TH located? Maybe it needs shielding from cool air
streams, etc.
They should make a digital RM TH that has an on/off temp differential
setting.
You could then set it to cycle on at 79 and off even a low as 73-F.
Use large floor fans to keep the air circulating as this will add to
your comfort.
Take a look at the "Human Comfort Zone Chart," on the linked page below.
The way most RM THs are now is that they have a cooling anticipator that
aids in keeping the temperature very close to the TH setting.
That is the wrong way to go if you want and need longer cycles to reduce
humidity levels and increase the operating SEER levels.
- udarrell - Darrell
--
Air Conditioning's Affordable Path to the "Human Comfort Zone Goal"
http://www.udarrell.com/air-conditioning-total-heat-enthalpy-latent-heat.html
JimL
Jul 17, 2006, 2:06:54 PM7/17/06
to
On 16 Jul 2006 22:13:23 -0700, "glynndaddy" <glynn...@yahoo.com>
wrote:
wrote:
yeah, what darrel said plus, my thermastat has a 1 or 2 degree
differential setting. The 2 setting makes it run longer between
cycles.
This time of year, in the hottest part of the day, a well designed
system should be running just about all the time.
m Ransley
Jul 17, 2006, 2:58:31 PM7/17/06
to
78f 72% humidity is not a comfortable setting. Your thermostat might
have a setting to increase cycle time, a longer time is also easier on
the equipment.
have a setting to increase cycle time, a longer time is also easier on
the equipment.
Pete C.
Jul 17, 2006, 3:09:14 PM7/17/06
to
I believe the OP was referring to outdoor humidity, not indoor. Were it
72% humidity indoor I think the OP would be complaining of problems
other than short cycle times.
Pete C.
glynndaddy
Jul 17, 2006, 5:33:55 PM7/17/06
to
Thanks to everyone for your help.
Is a thermostat, TSTAT and RM TH all the same thing?
If a properly running systems run for long periods of time, doesn't
that translate to high energy bills? What would be a reasonable ratio
of on to off time?
I didn't want to take much of anyone's time, but I guess I should
disclose that my system is not running right. It was installed in a
new house four years ago. I've had to have the system recharged 3
times, the last time a few weeks ago. The previous two times fixed the
short cycling, but not this time.
The AC company found a leak in my evaporator coil. I guess it needs to
be fixed, but it's going to be expensive. I was hoping that the
recharging would buy me some time, but i guess the leak has gotten too
big.
Lastly, when they found the problem, the guy did not reseal the
evaporator coil housing access panel. I just went up in the attic and
noticed there is some cold air coming out. I guess i will get up there
with duct tape, but I can't imagine it having that big an effect.
There is also air coming out of my drain pipe (because there is no cap
on it). I guess I will put some tape on that too.
Thanks everyone.
CJT
Jul 17, 2006, 6:10:51 PM7/17/06
to
JimL wrote:
No matter how hot it is, it can get hotter. I would say a well designed
system should be running _most_ of the time; you never want to run out
of reserve. If it's at a 50-60% duty cycle, it'll be effective removing
the humidity.
--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
JimL
Jul 18, 2006, 12:21:05 PM7/18/06
to
On Mon, 17 Jul 2006 22:10:51 GMT, CJT <abuj...@prodigy.net> wrote:
>JimL wrote:
>
>> On 16 Jul 2006 22:13:23 -0700, "glynndaddy" <glynn...@yahoo.com>
>> wrote:
>>
>>
>>>Is there a general rule-of-thumb for how long an air conditioner should
>>>run and how long it should stay off? I realize this probably depends
>>>on a variety of variables, but is there a rule-of-thumb. I've searched
>>>quite a bit and can not seem to find an answer.
>>>
>>>If it helps, my house is 1 story, 2400 sq ft. I have the thermostat
>>>set at 78. It is 85 degrees outside, humidy 72%.
>>>
>>>Right now, my a/c stays on for 8 - 10 minutes and goes off for 7 - 9
>>>minutes.
>>>
>>>Thanks for your help.
>>
>>
>> yeah, what darrel said plus, my thermastat has a 1 or 2 degree
>> differential setting. The 2 setting makes it run longer between
>> cycles.
>>
>> This time of year, in the hottest part of the day, a well designed
>> system should be running just about all the time.
>>
>>
>No matter how hot it is, it can get hotter. I would say a well designed
>system should be running _most_ of the time; you never want to run out
>of reserve. If it's at a 50-60% duty cycle, it'll be effective removing
>the humidity.
No,No.
You DO want to run out of reserve. A well designed system should
fall behind on the hottest day of the decade. It won't be able to
keep up. Your thermostat will be set at 78 but the temp will creep up
to 80, 81, 82...... etc.
Jason
Jul 18, 2006, 5:00:58 PM7/18/06
to
"glynndaddy" <glynn...@yahoo.com> wrote in message
news:1153172035....@h48g2000cwc.googlegroups.com...
> Thanks to everyone for your help.
>
> Lastly, when they found the problem, the guy did not reseal the
> evaporator coil housing access panel. I just went up in the attic and
> noticed there is some cold air coming out. I guess i will get up there
> with duct tape, but I can't imagine it having that big an effect.
> There is also air coming out of my drain pipe (because there is no cap
> on it). I guess I will put some tape on that too.
> evaporator coil housing access panel. I just went up in the attic and
> noticed there is some cold air coming out. I guess i will get up there
> with duct tape, but I can't imagine it having that big an effect.
> There is also air coming out of my drain pipe (because there is no cap
> on it). I guess I will put some tape on that too.
NEVER USE DUCT TAPE! Use foil tape as it will last. Duct tape will fail
over time.
CJT
Jul 18, 2006, 6:23:57 PM7/18/06
to
JimL wrote:
With global warming, the next summer it'll be 90, 91, 92 ...
glynndaddy
Jul 18, 2006, 9:06:09 PM7/18/06
to
Thanks to everyone again for your help.
My builder has contacted the AC contractor who installed the system and
they've agreed to replace the evaporator coil. I hope they do a good
job. Last month my bill was $270 to cool 2400 sq ft to 79 degrees.
JimL
Jul 18, 2006, 11:08:20 PM7/18/06
to
On 18 Jul 2006 18:06:09 -0700, "glynndaddy" <glynn...@yahoo.com>
wrote:
wrote:
I was just looking at warranty period on Goodman coils and the
standard warranty is 10 years on the coil with a new system and 5
years otherwise. Lifetime on the heat exchanger.
Good for you on getting a new coil. I suspect a botched install,
not a bad coil.
Robert Gammon
Jul 19, 2006, 7:56:34 AM7/19/06
to
from 10:00am to 10:00pm. Power bill DOUBLES. House is livable, but
uncomfortable, especially when guests are over.
50% duty cycle, but no more than once an hour, certainly no more than
once every 30 minutes. Any faster cycling than this is dangerous for
the compressor.
A house that is 'adequately' plugged against air leaks, and has
'adequate' insulation should not have a duty cycle of greater than 50%
and really should have a duty cycle of under 25%. Air leak plugs are
the new hot button, now that most new homes have at least R38 in the
ceiling and R24 in the walls, Course if we do manage to plug those
uncontrolled air leaks, then the house accumulates odors (cooking, body
odor - human and pets, solvents, cleaning fluids, paint, plastics......)
and we must then install a controlled ventilator.
JimL
Jul 19, 2006, 11:10:56 AM7/19/06
to
CJT
Jul 19, 2006, 8:46:59 PM7/19/06
to
after a power failure.
Denco AC - Carrier Dealer - 28 years experience- Licensed in Texas
Jul 5, 2013, 5:44:02 PM7/5/13
to
replying to glynndaddy, Denco AC - Carrier Dealer - 28 years experience-
Licensed in Texas wrote:
A refrigerant leak will have a huge impact on run time. The lower it gets,
the longer it will run. Adding more Freon will never solve the problem. A
a/c system is like a car tire in that it is air tight. If your car has a
low tire it is because it has a leak, adding air does nothing to repair
the tire or the leak. The same rule applies to a a/c system. If your unit
is 4 years old it should still be under warranty by the manufacturer and a
repair would cost you labor and refrigerant, The coil would be replaced by
the manufacturer. The leak will only get worse. And in time I running the
system low on refrigerant will/can destroy the compressor. As for run
time, the length a ac unit runs is determined by variables such as outdoor
temperature, heat gains through windows and doors and the amount of
insulation in your attic. These same variables determine the length of
tine the unit is off. I just a had a conversation with a customer who's
old system ran non stop, we installed a new system one ton larger and now
it runs 6-7 minutes and is off for 14-16 minutes. So the run time is 18
minutes per hour instead of running 20 hours a day like the old undersized
unit.
--
posted from
http://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
using HomeOwnersHub's Web, RSS and Social Media Interface
to home and garden related groups
Licensed in Texas wrote:
the longer it will run. Adding more Freon will never solve the problem. A
a/c system is like a car tire in that it is air tight. If your car has a
low tire it is because it has a leak, adding air does nothing to repair
the tire or the leak. The same rule applies to a a/c system. If your unit
is 4 years old it should still be under warranty by the manufacturer and a
repair would cost you labor and refrigerant, The coil would be replaced by
the manufacturer. The leak will only get worse. And in time I running the
system low on refrigerant will/can destroy the compressor. As for run
time, the length a ac unit runs is determined by variables such as outdoor
temperature, heat gains through windows and doors and the amount of
insulation in your attic. These same variables determine the length of
tine the unit is off. I just a had a conversation with a customer who's
old system ran non stop, we installed a new system one ton larger and now
it runs 6-7 minutes and is off for 14-16 minutes. So the run time is 18
minutes per hour instead of running 20 hours a day like the old undersized
unit.
--
posted from
http://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
using HomeOwnersHub's Web, RSS and Social Media Interface
to home and garden related groups
tra...@optonline.net
Jul 5, 2013, 7:25:44 PM7/5/13
to
then it's also taking a long time to cool down if it's been off
and you come home from a trip
and probably not performing very well on a lot of days that aren't
the hottest in a decade, but close enough. I want some decent reserve.
I agree that you don't want it grossly oversized, because that
causes problems too.
tra...@optonline.net
Jul 5, 2013, 7:27:48 PM7/5/13
to
was "dangerous", there would be a lot of broken AC's out there.
>
> A house that is 'adequately' plugged against air leaks, and has
> 'adequate' insulation should not have a duty cycle of greater than 50%
> and really should have a duty cycle of under 25%.
Mike Name
May 1, 2017, 10:14:11 AM5/1/17
to
replying to glynndaddy, Mike Name wrote:
Wow you set your stat at 78 degrees? Why even bother with owning an a/c unit,
get a dehumidifier. Seriously I am not a freeze freak and find 74 degrees to
get the top temp for comfort but 73 usually is where I set it to keep the wife
from complaining and guests.
--
for full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
Wow you set your stat at 78 degrees? Why even bother with owning an a/c unit,
get a dehumidifier. Seriously I am not a freeze freak and find 74 degrees to
get the top temp for comfort but 73 usually is where I set it to keep the wife
from complaining and guests.
--
for full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
trader_4
May 1, 2017, 11:15:02 AM5/1/17
to
keep a house at 78F?
TimR
May 1, 2017, 1:13:50 PM5/1/17
to
Oh wait, we had this conversation with Stormy. never mind.
Wayne Boatwright
May 1, 2017, 2:42:04 PM5/1/17
to
On Mon 01 May 2017 07:14:03a, Mike Name told us...
> replying to glynndaddy, Mike Name wrote:
> Wow you set your stat at 78 degrees? Why even bother with owning
> an a/c unit, get a dehumidifier. Seriously I am not a freeze freak
> and find 74 degrees to get the top temp for comfort but 73 usually
> is where I set it to keep the wife from complaining and guests.
>
A lot depends on where you live. We live in the Arizona desert and our
typical daytime summer temperatures can range from 105° F. to 120° F.
Our night time temperatures can still be as high as 100° F. Our
humidity levels are extremely low, so the differential temperature for
comfort is usually about 77-78° F. Set much lower than that it begins
to feel like a freezer.
When we lived in Ohio with high relative humidity and temperatures in
the high 80s to the mid 90s, I recall setting our thermostat to
anywhere from 72° F. to 75° F.
--
~~ If there's a nit to pick, some nitwit will pick it. ~~
~~ A mind is a terrible thing to lose. ~~
**********************************************************
Wayne Boatwright
> replying to glynndaddy, Mike Name wrote:
> Wow you set your stat at 78 degrees? Why even bother with owning
> an a/c unit, get a dehumidifier. Seriously I am not a freeze freak
> and find 74 degrees to get the top temp for comfort but 73 usually
> is where I set it to keep the wife from complaining and guests.
>
typical daytime summer temperatures can range from 105° F. to 120° F.
Our night time temperatures can still be as high as 100° F. Our
humidity levels are extremely low, so the differential temperature for
comfort is usually about 77-78° F. Set much lower than that it begins
to feel like a freezer.
When we lived in Ohio with high relative humidity and temperatures in
the high 80s to the mid 90s, I recall setting our thermostat to
anywhere from 72° F. to 75° F.
--
~~ If there's a nit to pick, some nitwit will pick it. ~~
~~ A mind is a terrible thing to lose. ~~
**********************************************************
Wayne Boatwright
Djayhan
May 2, 2017, 8:14:05 PM5/2/17
to
replying to Mike Name, Djayhan wrote:
Thank you, that's about the only sentence that makes sense on this page.
Thank you, that's about the only sentence that makes sense on this page.
Djayhan
May 2, 2017, 8:14:07 PM5/2/17
to
replying to trader_4, Djayhan wrote:
A little exaggerated like 100 degrees too, but 78 degrees seems pretty
pointless if you own an AC unit. 72° is considered be optimal 10 picture for
human beings to dwell in so why have been air conditioning unit attached to
your house if you're not gonna use it at optimum and temperatures or another
words he so conservative that you're never comfortable live a little and let
your $ serve you.
A little exaggerated like 100 degrees too, but 78 degrees seems pretty
pointless if you own an AC unit. 72° is considered be optimal 10 picture for
human beings to dwell in so why have been air conditioning unit attached to
your house if you're not gonna use it at optimum and temperatures or another
words he so conservative that you're never comfortable live a little and let
your $ serve you.
Ed Pawlowski
May 2, 2017, 10:08:47 PM5/2/17
to
On 5/2/2017 8:14 PM, Djayhan wrote:
> replying to trader_4, Djayhan wrote:
> A little exaggerated like 100 degrees too, but 78 degrees seems pretty
> pointless if you own an AC unit. 72° is considered be optimal 10 picture
> for
> human beings to dwell in so why have been air conditioning unit attached to
> your house if you're not gonna use it at optimum and temperatures or
> another
> words he so conservative that you're never comfortable live a little and
> let
> your $ serve you.
>
There are plenty of places in North American that are common with 100
> replying to trader_4, Djayhan wrote:
> A little exaggerated like 100 degrees too, but 78 degrees seems pretty
> pointless if you own an AC unit. 72° is considered be optimal 10 picture
> for
> human beings to dwell in so why have been air conditioning unit attached to
> your house if you're not gonna use it at optimum and temperatures or
> another
> words he so conservative that you're never comfortable live a little and
> let
> your $ serve you.
>
degrees in summer. Keeping the house at 78 and dry is quite
comfortable. Less shock to the body going in and out too.
Human comfort varies. 72 is not bad is summer, but in winter I like 65
for sleeting 70 for the rest of the day.
Vld5491
May 27, 2017, 1:44:15 AM5/27/17
to
replying to Denco AC - Carrier Dealer - 28, Vld5491 wrote:
Denco - AC - Carrier dealer you know I am from California and just had a new
AC condenser, coil and furnace replaced. I am experiencing exactly the same as
one of your customer after upgrading my AC to a 4t from a 3t unit, it now
running like 8-10 mins and shuts down from 18 - 22 mins. But I was wondering
cause I have not seen my electric bill after this installation, would this
lower or raise my electricity bill?Thanks
Denco - AC - Carrier dealer you know I am from California and just had a new
AC condenser, coil and furnace replaced. I am experiencing exactly the same as
one of your customer after upgrading my AC to a 4t from a 3t unit, it now
running like 8-10 mins and shuts down from 18 - 22 mins. But I was wondering
cause I have not seen my electric bill after this installation, would this
lower or raise my electricity bill?Thanks
trader_4
May 27, 2017, 10:53:37 AM5/27/17
to
If it's doing that when temps are hot, then it's oversized.
Was there a problem with the existing 3T not cooling enough?
What was the reason for going larger? As to the electric bill,
probably won't make any significant difference due to the timing.
It will use less electricity if it replaced an old honker.
The big downside to oversizing is that it won't run enough to
remove humidity on moderate days, won't run as long as it should
to mover air around and get balanced, etc.
Vld5491
May 28, 2017, 5:14:05 PM5/28/17
to
replying to trader_4, Vld5491 wrote:
We decided to upgrade from 3t to 4t because we have a townhouse with 1708
sqft. We had to close 3 registers/vents to get out 3 bedrooms to get to
comfortable level. Plus the contractor says in every 400 sq ft requires 1
tonage. With regards to humidity here in CA we have a very low humidity and we
are still on moderate weather, summer starts in June. Another thing that came
to mind is the frequency of the ac going on and off. Is this not bad for the
unit? Well the ac cool up pretty fast comparing to our old honker that's for
sure. Thanks for your infos. Have a wonderful memorial weekend😁
We decided to upgrade from 3t to 4t because we have a townhouse with 1708
sqft. We had to close 3 registers/vents to get out 3 bedrooms to get to
comfortable level. Plus the contractor says in every 400 sq ft requires 1
tonage. With regards to humidity here in CA we have a very low humidity and we
are still on moderate weather, summer starts in June. Another thing that came
to mind is the frequency of the ac going on and off. Is this not bad for the
unit? Well the ac cool up pretty fast comparing to our old honker that's for
sure. Thanks for your infos. Have a wonderful memorial weekend😁
trader_4
May 28, 2017, 7:22:06 PM5/28/17
to
On Sunday, May 28, 2017 at 5:14:05 PM UTC-4, Vld5491 wrote:
> replying to trader_4, Vld5491 wrote:
> We decided to upgrade from 3t to 4t because we have a townhouse with 1708
> sqft.
3 tons should be plenty for 1700 so ft.
> replying to trader_4, Vld5491 wrote:
> We decided to upgrade from 3t to 4t because we have a townhouse with 1708
> sqft.
We had to close 3 registers/vents to get out 3 bedrooms to get to
> comfortable level.
Plus the contractor says in every 400 sq ft requires 1
> tonage.
With regards to humidity here in CA we have a very low humidity and we
> are still on moderate weather, summer starts in June. Another thing that came
> to mind is the frequency of the ac going on and off. Is this not bad for the
> unit?
Ed Pawlowski
May 28, 2017, 8:10:05 PM5/28/17
to
On 5/28/2017 7:22 PM, trader_4 wrote:
> On Sunday, May 28, 2017 at 5:14:05 PM UTC-4, Vld5491 wrote:
>> replying to trader_4, Vld5491 wrote:
>> We decided to upgrade from 3t to 4t because we have a townhouse with 1708
>> sqft.
>
> 3 tons should be plenty for 1700 so ft.
>
I have 2100 sq. ft. and cool it with 2 1/2 ton. Of course, conditions
> On Sunday, May 28, 2017 at 5:14:05 PM UTC-4, Vld5491 wrote:
>> replying to trader_4, Vld5491 wrote:
>> We decided to upgrade from 3t to 4t because we have a townhouse with 1708
>> sqft.
>
> 3 tons should be plenty for 1700 so ft.
>
vary and the contractor should have run the manual J calculations.
http://www.loadcalc.net/
http://www.wikihow.com/Calculate-BTU-Per-Square-Foot#Determining_the_Correct_Cooling_Capacity_sub
> We had to close 3 registers/vents to get out 3 bedrooms to get to
>> comfortable level.
>
> Probably because something is wrong with the system, design, etc.
>
>
>
> Plus the contractor says in every 400 sq ft requires 1
>> tonage.
>
> That contractor is an idiot. Following that logic, a 2500 so ft house needs 6 tons? A 3000 so ft needs 7+ tons? You can do a manual J calculation which factors in size, insulation,windows, exposure, climate to get a correct number. That's why you have a system that is short cycling.
>
summer.
Vld5491
May 29, 2017, 6:44:06 PM5/29/17
to
replying to trader_4, Vld5491 wrote:
Thank you so much for the infos. Have a nice day😁
JoeBlow
Jul 13, 2017, 7:14:09 AM7/13/17
to
replying to Mike Name, JoeBlow wrote:
We keep our thermostat set on 78 in the summer. If we were to set it at 73 we
would have to wear sweatpants and socks just to keep from freezing! 73 is what
our basement temp is and it's too chilly down there. I like sitting around in
my underwear and a t-shirt during the summer, so 73 would be too cold. Plus,
we don't want to give any more money to the energy company than we have to! In
the winter we set it on 67 and bundle up in sweat pants and sweat shirt and
socks. Plus, when I'm sitting down, I have a blanket covering my feet and
legs.
We keep our thermostat set on 78 in the summer. If we were to set it at 73 we
would have to wear sweatpants and socks just to keep from freezing! 73 is what
our basement temp is and it's too chilly down there. I like sitting around in
my underwear and a t-shirt during the summer, so 73 would be too cold. Plus,
we don't want to give any more money to the energy company than we have to! In
the winter we set it on 67 and bundle up in sweat pants and sweat shirt and
socks. Plus, when I'm sitting down, I have a blanket covering my feet and
legs.
Wayne Boatwright
Jul 13, 2017, 8:02:04 PM7/13/17
to
On Thu 13 Jul 2017 04:14:02a, JoeBlow told us...
> replying to Mike Name, JoeBlow wrote:
> We keep our thermostat set on 78 in the summer. If we were to set
> it at 73 we would have to wear sweatpants and socks just to keep
> from freezing! 73 is what our basement temp is and it's too chilly
> down there. I like sitting around in my underwear and a t-shirt
> during the summer, so 73 would be too cold. Plus, we don't want to
> give any more money to the energy company than we have to! In the
> winter we set it on 67 and bundle up in sweat pants and sweat
> shirt and socks. Plus, when I'm sitting down, I have a blanket
> covering my feet and legs.
>
We keep our thermostat set at 77°F. year round. If we want to feel
cooler than that, we switch on the ceiliong fans.
> replying to Mike Name, JoeBlow wrote:
> We keep our thermostat set on 78 in the summer. If we were to set
> it at 73 we would have to wear sweatpants and socks just to keep
> from freezing! 73 is what our basement temp is and it's too chilly
> down there. I like sitting around in my underwear and a t-shirt
> during the summer, so 73 would be too cold. Plus, we don't want to
> give any more money to the energy company than we have to! In the
> winter we set it on 67 and bundle up in sweat pants and sweat
> shirt and socks. Plus, when I'm sitting down, I have a blanket
> covering my feet and legs.
>
cooler than that, we switch on the ceiliong fans.
patrici...@gmail.com
Sep 17, 2017, 12:24:31 PM9/17/17
to
The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
trader_4
Sep 17, 2017, 1:12:37 PM9/17/17
to
On Sunday, September 17, 2017 at 12:24:31 PM UTC-4, patrici...@gmail.com wrote:
> The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
Find a thermostat that lets you adjust how often it runs, either by
> The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
allowing adjustment of the swing points, ie does it go on when the temp
drops by .5 deg or 1 deg, etc., or by setting the number of cycles per
hour. I have a Honeywell VisionPro and it uses the latter method.
Since you're concerned about humidity, I'd get one that also controls
that. Essentially, if you set it to say 75F and humidity is above a
set point, it will run it anyway within limits, allowing temp to drop
to say 73 or 74 to reduce humidity. I don't have that, Honeywell
probably has ones that do. I've been very happy with the VP series
that I've had. You can find them on Ebay. Also, if I was buying one
today I'd get one that is internet connected. It's a nice feature
where if you're coming home early, from a trip, etc you can fire
it back up from your phone. Also, you can check while you're away,
see what the temp is, etc.
Vic Smith
Sep 17, 2017, 1:27:55 PM9/17/17
to
On Sun, 17 Sep 2017 09:24:25 -0700 (PDT), patrici...@gmail.com wrote:
>The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info
>here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
I live in your area, FWIW. Cycling has a lot to do with your thermostat's "anticipator."
>The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info
>here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
I think I have mine maxed to avoid excessive cycling.
Thermostat placement is also important, as is air circulation in your home.
Unless it's in the 90's, mine cycles only enough to reach the temp the thermostat is set
to. That doesn't mean it's the same temp everywhere in the house, just the hallway where
the thermostat is mounted on the wall.
It's important to have good air circulation to avoid hot spots. I have ceiling fans.
I'll try to remember to time the cycling for you today. We should be close to the same
temp.
patrici...@gmail.com
Sep 18, 2017, 12:24:30 AM9/18/17
to
Thank You Vic and trader_4 for your specificity. I am so upset about this situation, so helpful answers are appreciated. As a single female, I'm tired of getting screwed by contractors. The upsell of the 2.5 ton unit for my small place was where the problems started. It sounded like a jet was taking off in my living room every time the blower started. The humidity is so high, I have to run the A/C until I'm freezing here at 68 or 69 degrees to get it down to 55%. Since I complained to the contractor right away, they replaced the components outside with smaller ones, but I don't think that helped. At this point I'm not sure what is reasonable to ask them to do. I believed them when they said "stuff happens" when the blower motor went out a couple of weeks ago when the thing was only 13 months old. Reading these threads and some articles, I'm finding out just how hard it is on certain components like motors and such when its constantly starting from zero. Someone likened it to turning your car off at every stop light. So, I will no longer buy the "stuff happens" theory especially if someone can tell me my system is short cycling. Today it was in the lower 80s outside. I was trying to maintain a 74 degree temp. The A/C was on for 3-7 minutes and off for 7-12 minutes, most of the day. BTW, the thermostat is in a little hallway. No sunlight, drafts or vents. And also, the lower bills I was promised never happened. My new, high efficiency system is not so efficient. Since the system is new, replacing it is not a cost-effective option. Maybe your advice regarding a thermostat that can "stretch" the cycle a bit could save on some wear and tear.
trader_4
Sep 18, 2017, 3:54:02 AM9/18/17
to
On Monday, September 18, 2017 at 12:24:30 AM UTC-4, patrici...@gmail.com wrote:
> Thank You Vic and trader_4 for your specificity. I am so upset about this situation, so helpful answers are appreciated. As a single female, I'm tired of getting screwed by contractors. The upsell of the 2.5 ton unit for my small place was where the problems started. It sounded like a jet was taking off in my living room every time the blower started. The humidity is so high, I have to run the A/C until I'm freezing here at 68 or 69 degrees to get it down to 55%. Since I complained to the contractor right away, they replaced the components outside with smaller ones, but I don't think that helped. At this point I'm not sure what is reasonable to ask them to do. I believed them when they said "stuff happens" when the blower motor went out a couple of weeks ago when the thing was only 13 months old. Reading these threads and some articles, I'm finding out just how hard it is on certain components like motors and such when its constantly starting from zero. Someone likened it to turning your car off at every stop light. So, I will no longer buy the "stuff happens" theory especially if someone can tell me my system is short cycling. Today it was in the lower 80s outside. I was trying to maintain a 74 degree temp. The A/C was on for 3-7 minutes and off for 7-12 minutes, most of the day. BTW, the thermostat is in a little hallway. No sunlight, drafts or vents. And also, the lower bills I was promised never happened. My new, high efficiency system is not so efficient. Since the system is new, replacing it is not a cost-effective option. Maybe your advice regarding a thermostat that can "stretch" the cycle a bit could save on some wear and tear.
While it's true that short cycling puts more strain on the motors and isn't as efficient, it's not why your motor failed in just one year. It might make a difference of it lasting 15 years instead of 20 or something like that, but not failing in just a year. Was it a basic motor or the new fancy variable speed ECM type? The latter is more failure prone. I had the ECM fan on the outdoor condenser go on my theme after just 2 years. That's what you get in the quest for higher seers. I replaced it myself for $90 with a basic standard motor, which was available from many sources and fit. A new ECM one would have cost 3x or 4x that.
> Thank You Vic and trader_4 for your specificity. I am so upset about this situation, so helpful answers are appreciated. As a single female, I'm tired of getting screwed by contractors. The upsell of the 2.5 ton unit for my small place was where the problems started. It sounded like a jet was taking off in my living room every time the blower started. The humidity is so high, I have to run the A/C until I'm freezing here at 68 or 69 degrees to get it down to 55%. Since I complained to the contractor right away, they replaced the components outside with smaller ones, but I don't think that helped. At this point I'm not sure what is reasonable to ask them to do. I believed them when they said "stuff happens" when the blower motor went out a couple of weeks ago when the thing was only 13 months old. Reading these threads and some articles, I'm finding out just how hard it is on certain components like motors and such when its constantly starting from zero. Someone likened it to turning your car off at every stop light. So, I will no longer buy the "stuff happens" theory especially if someone can tell me my system is short cycling. Today it was in the lower 80s outside. I was trying to maintain a 74 degree temp. The A/C was on for 3-7 minutes and off for 7-12 minutes, most of the day. BTW, the thermostat is in a little hallway. No sunlight, drafts or vents. And also, the lower bills I was promised never happened. My new, high efficiency system is not so efficient. Since the system is new, replacing it is not a cost-effective option. Maybe your advice regarding a thermostat that can "stretch" the cycle a bit could save on some wear and tear.
If you replace the thermostat and stop the short cycles, you may notice an improvement in energy use too. Download the install manuals for any new ones you're considering. I know on the Honeywell vision pro you can set the number of cycles per hour. They also have adaptive recovery, where after having the thermostat set back, when you set the time for it to resume, you pick the time and temp you want and it figures out how much earlier to start it to reach that temp at that time,based on history and current conditions.
Uncle Monster
Sep 18, 2017, 12:27:05 PM9/18/17
to
On Sunday, September 17, 2017 at 11:24:31 AM UTC-5, patrici...@gmail.com wrote:
> The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
I've a question for you. The size of your AC unit seems to be too big for your small well insulated house, did the HVAC contractor do any calculations or take into account the energy saving measures you have taken? I've a few more questions I'm formulating since one of the things I did when I was still working was HVAC system installation and repair. ヽ(ヅ)ノ
> The question was about short cycling and how he could determine if his was short cycling. Most of the posts here were about what temp is comfortable and other useless information. I love the "wrong again" comment. That was also helpful especially without a reason. I'm pretty sure my one year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had the compressor and outdoor components exchanged for 2 ton components within two weeks. The humidity is always in the upper fifties so it never feels good. Another sign it's too big. Not surprisingly, the blower motor went out at 12 months. I was lead to believe it was a manufacturing problem. Doesn't take a genious to figure out a system turning off and on too often will also cause wear and tear. Which leads us back to the original question....how short is too short? It was hot here in Chicago yesterday, 85, and my newly repaired A/C was on 7 minutes and off 7 minutes which I felt was too short. Still at a loss given the info here. It was hot, am I wrong in thinking it was too short? BTW, I realize insulation, window and door leaks must factor in. Four years ago I had 8 inches of insulation blown the attic. My old two ton A/C never had such short cycles, not even with 4 inches of insulation. I understand on a hot day 10 minutes on and 10 minutes off or three cycles an hour could be appropriate from info I got elsewhere. Anyone agree? Comments? I can't replace worn out parts every year.
[8~{} Uncle AC Monster
Wayne Boatwright
Sep 18, 2017, 2:48:11 PM9/18/17
to
On Sun 17 Sep 2017 10:27:43a, Vic Smith told us...
I've never checked the settings inside my thermostat as I've had no
reason to. I have checked the temperature in every room except the
kitchen (it has no vent and is closed off except for the doorway.
OUr temperature variant is no more than 2 degrees amongst all the
rooms. Our unit cycles about 3 times an hour. We live in central
AZ. We do use ceiling fans to help average out the temperature, and
we keep the thermostat set at 77° F.
reason to. I have checked the temperature in every room except the
kitchen (it has no vent and is closed off except for the doorway.
OUr temperature variant is no more than 2 degrees amongst all the
rooms. Our unit cycles about 3 times an hour. We live in central
AZ. We do use ceiling fans to help average out the temperature, and
we keep the thermostat set at 77° F.
Vic Smith
Sep 18, 2017, 4:25:46 PM9/18/17
to
On Mon, 18 Sep 2017 18:48:05 GMT, Wayne Boatwright <waynebo...@xgmail.com> wrote:
>On Sun 17 Sep 2017 10:27:43a, Vic Smith told us...
>
>> On Sun, 17 Sep 2017 09:24:25 -0700 (PDT), patrici...@gmail.com
>> wrote:
>>
>>>The question was about short cycling and how he could determine if
>>>his was short cycling.
snip
>On Sun 17 Sep 2017 10:27:43a, Vic Smith told us...
>
>> On Sun, 17 Sep 2017 09:24:25 -0700 (PDT), patrici...@gmail.com
>> wrote:
>>
>>>The question was about short cycling and how he could determine if
>>>his was short cycling.
>>
>> I live in your area, FWIW. Cycling has a lot to do with your
>> thermostat's "anticipator." I think I have mine maxed to avoid
>> excessive cycling. Thermostat placement is also important, as is
>> air circulation in your home. Unless it's in the 90's, mine cycles
>> only enough to reach the temp the thermostat is set to. That
>> doesn't mean it's the same temp everywhere in the house, just the
>> hallway where the thermostat is mounted on the wall.
>> It's important to have good air circulation to avoid hot spots. I
>> have ceiling fans. I'll try to remember to time the cycling for
>> you today. We should be close to the same temp.
>>
>
>I've never checked the settings inside my thermostat as I've had no
>reason to. I have checked the temperature in every room except the
>kitchen (it has no vent and is closed off except for the doorway.
>OUr temperature variant is no more than 2 degrees amongst all the
>rooms. Our unit cycles about 3 times an hour. We live in central
>AZ. We do use ceiling fans to help average out the temperature, and
>we keep the thermostat set at 77° F.
Mine was cycling about 3 times an hour yesterday. It was 82 outside and it was set at 79.
>> I live in your area, FWIW. Cycling has a lot to do with your
>> thermostat's "anticipator." I think I have mine maxed to avoid
>> excessive cycling. Thermostat placement is also important, as is
>> air circulation in your home. Unless it's in the 90's, mine cycles
>> only enough to reach the temp the thermostat is set to. That
>> doesn't mean it's the same temp everywhere in the house, just the
>> hallway where the thermostat is mounted on the wall.
>> It's important to have good air circulation to avoid hot spots. I
>> have ceiling fans. I'll try to remember to time the cycling for
>> you today. We should be close to the same temp.
>>
>
>I've never checked the settings inside my thermostat as I've had no
>reason to. I have checked the temperature in every room except the
>kitchen (it has no vent and is closed off except for the doorway.
>OUr temperature variant is no more than 2 degrees amongst all the
>rooms. Our unit cycles about 3 times an hour. We live in central
>AZ. We do use ceiling fans to help average out the temperature, and
>we keep the thermostat set at 77° F.
I was wrong about having an adjustable anticipator - that was my old thermostat.
The Honeywell I have now has CPH (cycles per hour) and since I don't remember programming
it, it's probably set to the default, which is 4 (every 15 minutes.)
The thermostat must have anticipator logic (aka hysteresis) built in. They don't give
such technical details in the user manual. From experience, it's about 1 degree F.
Patricia can check the user manual for her thermostat. Should be able stop the
short-cycling if the thermostat setting is causing it. That's all I know.
trader_4
Sep 18, 2017, 4:31:52 PM9/18/17
to
weeks later for 2 ton. But I missed that the place is only 750 sq ft!
That's like three 20 x 12 rooms. We don't know the rest of the situation,
but I agree, it sure seems oversized, still, to me. 2.5 tons is 30K BTUs.
It's like having a 10K BTU unit in each room. Would you buy a 10K
unit for that size room? Even more remarkable is that
they had a 2.5 in there, knew that was too big, but then only went down
to 2.0? It's probably useable with that size if she gets the short
cycling fixed, but it's most likely not optimum either.
What was in there before they put the new 2.5 ton in? What was the
experience with the old unit?
Ed Pawlowski
Sep 18, 2017, 5:02:54 PM9/18/17
to
shakers. The lower level is 1000 feet but the utility/laundry area is
closed off. The remaining portion is comfy with an 8,000 btu unit. The
upstairs is also 1000 feet. One end has 10,000 btu and our bedroom has
6000. So, I'm doing a larger area with just over a ton.
Insulation, window area climate, etc has to be considered but I think
she is still oversized ay at least a half ton, maybe more.
patrici...@gmail.com
Sep 19, 2017, 2:24:03 AM9/19/17
to
I supposedly had a two ton originally. Back when it was installed in the sixties or seventies central A/C was sort of new. They really didn't know how to size them then. I probably could have gotten away with a 1.5 ton. The experience with the previous unit was great. Never noticed short cycling, not even when I only had 4 inches of insulation in the attic. I lived under those conditions for 19 years. If I was too hot or cold all the time or if I heard the thing start up so frequently, I would have fixed that sooner. The house is only 720 sq ft. Two bedrooms, one bath. I had three estimates, none of them did a calculation. Yes, I have the fancy, variable speed ECM type. Thanks for letting me know your opinion about that motor going out so soon. BTW, it was the blower motor, inside that gave out. Three cycles an hour seems reasonable to me. I'm having about 4, which isn't terrible, but, it's the swings and the humidity. I had times yesterday when the system was only on for three minutes. This morning it was 70 degrees with 58% humidity inside. May as well have been 80 degrees. I had to run the A/C until it was 68 just to get a reasonable humidity level. If my 1 y/o thermostat does not have the options I need for adjusting the cycles, I'll replace it. Also, I think I can have the blower speed adjusted. I'm not dealing with this. May as well go Bluetooth while I'm at it. I'm pretty sure the shorter cycles are from an oversized unit. Thanks to all of you for your valuable advice.
Bubba's HVAC
Sep 19, 2017, 4:43:14 AM9/19/17
to
On 09/19/2017 02:23 AM, patrici...@gmail.com wrote:
> I supposedly had a two ton originally. Back when it was installed in the sixties or seventies central A/C was sort of new. They really didn't know how to size them then. I probably could have gotten away with a 1.5 ton. The experience with the previous unit was great. Never noticed short cycling, not even when I only had 4 inches of insulation in the attic. I lived under those conditions for 19 years. If I was too hot or cold all the time or if I heard the thing start up so frequently, I would have fixed that sooner. The house is only 720 sq ft. Two bedrooms, one bath. I had three estimates, none of them did a calculation. Yes, I have the fancy, variable speed ECM type. Thanks for letting me know your opinion about that motor going out so soon. BTW, it was the blower motor, inside that gave out. Three cycles an hour seems reasonable to me. I'm having about 4, which isn't terrible, but, it's the swings and the humidity. I had times yesterday when the system was only on for three minutes. This morning it was 70 degrees with 58% humidity inside. May as well have been 80 degrees. I had to run the A/C until it was 68 just to get a reasonable humidity level. If my 1 y/o thermostat does not have the options I need for adjusting the cycles, I'll replace it. Also, I think I can have the blower speed adjusted. I'm not dealing with this. May as well go Bluetooth while I'm at it. I'm pretty sure the shorter cycles are from an oversized unit. Thanks to all of you for your valuable advice.
Until you put an hour meter on the compressor to see how much it actually runs from noon to 6pm on a typical hot sunny day in your climate, you're just guessing at capacity required.
> I supposedly had a two ton originally. Back when it was installed in the sixties or seventies central A/C was sort of new. They really didn't know how to size them then. I probably could have gotten away with a 1.5 ton. The experience with the previous unit was great. Never noticed short cycling, not even when I only had 4 inches of insulation in the attic. I lived under those conditions for 19 years. If I was too hot or cold all the time or if I heard the thing start up so frequently, I would have fixed that sooner. The house is only 720 sq ft. Two bedrooms, one bath. I had three estimates, none of them did a calculation. Yes, I have the fancy, variable speed ECM type. Thanks for letting me know your opinion about that motor going out so soon. BTW, it was the blower motor, inside that gave out. Three cycles an hour seems reasonable to me. I'm having about 4, which isn't terrible, but, it's the swings and the humidity. I had times yesterday when the system was only on for three minutes. This morning it was 70 degrees with 58% humidity inside. May as well have been 80 degrees. I had to run the A/C until it was 68 just to get a reasonable humidity level. If my 1 y/o thermostat does not have the options I need for adjusting the cycles, I'll replace it. Also, I think I can have the blower speed adjusted. I'm not dealing with this. May as well go Bluetooth while I'm at it. I'm pretty sure the shorter cycles are from an oversized unit. Thanks to all of you for your valuable advice.
https://www.amazon.com/Generator-OZ-USA-diesel-motorhome-propane/dp/B01KAYZ0GE
mako...@yahoo.com
Sep 19, 2017, 9:14:55 AM9/19/17
to
>
>
> Until you put an hour meter on the compressor to see how much it actually runs from noon to 6pm on a typical hot sunny day in your climate, you're just guessing at capacity required.
>
I would find it hard to believe that everything could be fine with 2 tons and not fine with 2.5 tons.
Maybe the numbers are wrong or maybe something else has changed.
So lets help the lady. Short of changing the AC unit, what could she do to reduce the humidity.
Maybe she should get a stand alone de-humidifier, then the AC would not have to run as much to de-humidify and it won't be so cold.
Any other ideas?
mark
Ed Pawlowski
Sep 19, 2017, 9:34:57 AM9/19/17
to
evidently not the best.
She could run a humidifier to remove moisture or she can run the heat if
it is not the same unit. Running heat is fairly common in places that
must have humidity control more than temperature control. I've seen it
done in a printing plant on cool damp days,
trader_4
Sep 19, 2017, 1:17:35 PM9/19/17
to
and it was short cycling so two weeks later they swapped it for a 2.
But re-reading it, I think you're right, she had a 2 ton, they
inexplicably upped it to 2.5 tons on a 750 sq ft house. Like Ed said,
I can see that creating a problem for two reasons. One is that at
2 tons, it was likely already too big, making it 20% bigger would
push it from marginal for controlling humidity to unacceptable.
The other is an old system was probably not running at full capacity.
When I had my system replaced, the new one, while of equal tons,
sure puts out a lot more cooling capacity. If I had it to do over
I'd have gone with a smaller unit too.
Another solution for these issues is the two stage units. I hadn't
thought about that from a humidity control standpoint when I was
replacing mine. But with a two stage you can have it sized bigger
so it can cool quickly when needed, but at the lower stage it can
run a lot longer for period when a lot of cooling isn't needed,
which would include to get the humidity down.
Tekkie®
Sep 19, 2017, 4:53:21 PM9/19/17
to
Uncle Monster posted for all of us...
>
> On Sunday, September 17, 2017 at 11:24:31 AM UTC-5, patrici...@gmail.com wrote:
> > The question was about short cycling and how he could determine if his
was short cycling. Most of the posts here were about what temp is
comfortable and other useless information. I love the "wrong again" comment.
That was also helpful especially without a reason. I'm pretty sure my one
year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had
the compressor and outdoor components exchanged for 2 ton components within
two weeks. The humidity is always in the upper fifties so it never feels
good. Another sign it's too big. Not surprisingly, the blower motor went out
at 12 months. I was lead to believe it was a manufacturing problem. Doesn't
take a genius to figure out a system turning off and on too often will also
>
> [8~{} Uncle AC Monster
BINGO BINGO BINGO +500
--
Tekkie
>
> On Sunday, September 17, 2017 at 11:24:31 AM UTC-5, patrici...@gmail.com wrote:
> > The question was about short cycling and how he could determine if his
was short cycling. Most of the posts here were about what temp is
comfortable and other useless information. I love the "wrong again" comment.
That was also helpful especially without a reason. I'm pretty sure my one
year old, 7K, 2.5 ton system is too big for my 720 square foot house. I had
the compressor and outdoor components exchanged for 2 ton components within
two weeks. The humidity is always in the upper fifties so it never feels
good. Another sign it's too big. Not surprisingly, the blower motor went out
at 12 months. I was lead to believe it was a manufacturing problem. Doesn't
cause wear and tear. Which leads us back to the original question....how
short is too short? It was hot here in Chicago yesterday, 85, and my newly
repaired A/C was on 7 minutes and off 7 minutes which I felt was too short.
Still at a loss given the info here. It was hot, am I wrong in thinking it
was too short? BTW, I realize insulation, window and door leaks must factor
in. Four years ago I had 8 inches of insulation blown the attic. My old two
ton A/C never had such short cycles, not even with 4 inches of insulation. I
understand on a hot day 10 minutes on and 10 minutes off or three cycles an
hour could be appropriate from info I got elsewhere. Anyone agree? Comments?
I can't replace worn out parts every year.
>
>
> I've a question for you. The size of your AC unit seems to be too big for your small well insulated house, did the HVAC contractor do any calculations or take into account the energy saving measures you have taken? I've a few more questions I'm formulating since one of the things I did when I was still working was HVAC system installation and repair. ?(?)?
short is too short? It was hot here in Chicago yesterday, 85, and my newly
repaired A/C was on 7 minutes and off 7 minutes which I felt was too short.
Still at a loss given the info here. It was hot, am I wrong in thinking it
was too short? BTW, I realize insulation, window and door leaks must factor
in. Four years ago I had 8 inches of insulation blown the attic. My old two
ton A/C never had such short cycles, not even with 4 inches of insulation. I
understand on a hot day 10 minutes on and 10 minutes off or three cycles an
hour could be appropriate from info I got elsewhere. Anyone agree? Comments?
I can't replace worn out parts every year.
>
>
>
> [8~{} Uncle AC Monster
BINGO BINGO BINGO +500
--
Tekkie
Ralph Mowery
Sep 19, 2017, 5:44:34 PM9/19/17
to
In article <1tfwB.374997$xN2.1...@fx44.iad>, Tek...@comcast.net
says...
size of you AC. It usually runs about $ 100. The AC guys should do
that for you.
Here is a link to an online calculator. I have not tried it as my AC
seems to work fine.
http://www.loadcalc.net/
That 2 to 2 1/2 ton unit seems to be about 2 times as large as it should
be unless you have almost no insulation and are in a very hot area.
I only have a 2 1/2 ton heat pump in a house that is almost 3 times that
in the middle of NC.
says...
>
> Uncle Monster posted for all of us...
>
> >
> Uncle Monster posted for all of us...
>
> >
> > I've a question for you. The size of your AC unit seems to be too big for your small well insulated house, did the HVAC contractor do any calculations or take into account the energy saving measures you have taken? I've a few more questions I'm formulating since one of the things I did when I was still working was HVAC system
installation and repair. ?(?)?
> >
> > [8~{} Uncle AC Monster
>
> BINGO BINGO BINGO +500
There is a program called Manual J that should be ran to calculate the
installation and repair. ?(?)?
> >
> > [8~{} Uncle AC Monster
>
> BINGO BINGO BINGO +500
size of you AC. It usually runs about $ 100. The AC guys should do
that for you.
Here is a link to an online calculator. I have not tried it as my AC
seems to work fine.
http://www.loadcalc.net/
That 2 to 2 1/2 ton unit seems to be about 2 times as large as it should
be unless you have almost no insulation and are in a very hot area.
I only have a 2 1/2 ton heat pump in a house that is almost 3 times that
in the middle of NC.
Wayne Boatwright
Sep 19, 2017, 10:05:14 PM9/19/17
to
On Tue 19 Sep 2017 02:44:23p, Ralph Mowery told us...
We live in a 1500 sq ft condo in central Phoenix AZ. Obviously our
heat load is significantly different than the OPs. I believe our AC
unit is 3 tons, and we typically maintain 77° F. 24/7. On average I
think our unit cycles on and off every 15 minutes.
heat load is significantly different than the OPs. I believe our AC
unit is 3 tons, and we typically maintain 77° F. 24/7. On average I
think our unit cycles on and off every 15 minutes.
Patricia N.
Sep 20, 2017, 1:14:23 AM9/20/17
to
The old unit ran efficiently for 22 years, for me and only needed one or two thermocouples. After 22 years, I know how it sounded, how it felt and the duration of the cycle.
These newer models are powerful. I think I will take the advice given to change the cycles per hour, etc, if my thermostat will let me. It might be too dumb. I can get a fancy, new thermostat. Another option I didn't mentioned is getting the tech to change the blower speed. I think they have 3 or 4 settings. It may be on factory default. I had them do that when they swapped out the 2.5 ton components but I have since had to have the new blower motor replaced, so it's probably still on factory default. I came here initially because my short cycling system seems worse since the new blower motor was installed on 09/01.
patrici...@gmail.com
Sep 20, 2017, 1:40:14 AM9/20/17
to
Uncle Monster
Sep 20, 2017, 2:00:02 AM9/20/17
to
[8~{} Uncle AC Monster
mako...@yahoo.com
Sep 20, 2017, 10:08:04 AM9/20/17
to
. It is drastically different than the old unit, not sure why. When it starts blowing, you may as well be on the tarmac at O'hare, same thing.
>
snip
>
>. If the cfm, blower speed, is too high, the evaporator coil(cold part) on the furnace/air handler, doesn't efficiently remove moisture from the air. The air handler and evaporator coil have cfm ratings and need to be matched. I hope you can find an HVAC contractor who knows what he/she/it is doing. ヽ(ヅ)
It sounds like you might be able to improve things by getting the blower to run at a slower speed. That is usually a minor modification. I'm not sure how you would do that on your particular unit but an HVAC guy should know.
mark
trader_4
Sep 20, 2017, 1:29:08 PM9/20/17
to
very slowly. Also, the speed is programmable via dip switches
on the furnace control board. Suggest she look online for an
*install manual* for her unit. It will define how the unit works,
the options, switch settings, etc. At a lower blower speed you
would expect it to remove more humidity and to run longer.
Also, I guess what I thought initially was right, that they put in
a 2.5 ton then swapped it out to 2 ton because of the complaints.
AGain, given it's only 750 sq ft and that there was trouble, you'd
think they would have gone to 1.5.
Mark Lloyd
Sep 20, 2017, 4:55:46 PM9/20/17
to
On 09/20/2017 12:40 AM, patrici...@gmail.com wrote:
[snip]
> Trader_4, the two stage unit is a great idea for someone looking for a new system. I just spent 7K, so I can't do that. I wish I had. I think it would be great way to dehumidify. Also, it would be good for people that dislike the fluctuations. It's a drag when you get cold and wonder when the heat will kick on next. Less hot/cold spots. A smaller unit would be good too. Also,not an option for me now. I cannot stress enough to people who know my story. Don't let them sell you an AC that is too big and get a Manual J calculation.
>
I'm in east Texas, which has had a big humidity problem. I got a 2-stage
A/C (3 ton for about what you paid) a few years ago, and it has really
helped.
--
96 days until the winter celebration (Monday December 25, 2017 12:00:00
AM for 1 day).
Mark Lloyd
http://notstupid.us/
"FAILURE IS NOT AN OPTION. It comes bundled with the software."
[snip]
> Trader_4, the two stage unit is a great idea for someone looking for a new system. I just spent 7K, so I can't do that. I wish I had. I think it would be great way to dehumidify. Also, it would be good for people that dislike the fluctuations. It's a drag when you get cold and wonder when the heat will kick on next. Less hot/cold spots. A smaller unit would be good too. Also,not an option for me now. I cannot stress enough to people who know my story. Don't let them sell you an AC that is too big and get a Manual J calculation.
>
A/C (3 ton for about what you paid) a few years ago, and it has really
helped.
--
96 days until the winter celebration (Monday December 25, 2017 12:00:00
AM for 1 day).
Mark Lloyd
http://notstupid.us/
"FAILURE IS NOT AN OPTION. It comes bundled with the software."
Jminter80
Sep 29, 2017, 7:44:06 PM9/29/17
to
replying to Wayne Boatwright, Jminter80 wrote:
Honestly there isnt one answer for every situation but your unit should run
enough to keep humidity at acceptable ranges. The person with the 800 sq ft
house is going to have issues with humidity due to size of house and 2.5 ton
is most likely oversized. Depending on insulation and windows your looking at
a 1.5 - 2 ton unit. Run cycles will change with the temperature outside as
well as humidity levels. Best thing to do is set indoor fan to circulating
mode if that option is available to keep air moving due to the size of the
house also you should be able to adjust speed if it sounds like a jet. There
are more options besides smaller system. The off cycle is going to be effected
by how well the house is insulated as well. If its not insulated well than
your house is going to heat up faster when the ac is off therefore ot will
cucle more often. Also I am not sure how much saving you anticipated on an
800sq ft house because ot doesnt use enough energy in the forst place to allow
for a noticeable change either way. If it were a 2500sq ft house with a $400
electric then you could expect a noticeable saving by updating to a newer and
more energy efficient system. Think of percentages when dealing with savings
also which means 10 percent of $100 is less than 10 percent of $400. Back to
run time....unit should be sized properly to have a long enough run time which
in my opinion is 5-10 minutes to properly remove humidity and off time should
be around 20-35 minutes. This varies because an old house will gain heat
faster than a new well insulated house. There is also room for error on sizing
due to all the variables and size of home which I always lean to the 1/2 ton
larger side for the abnormally high temps we experience for a week at a time
in southern Illinois. Never have had one issue with run times or humidity. My
last customer questioned it running every 30 minutes but he came from window
units and thought that was to much but you have to also factor in the comfort
throughout home which means a customer shouldnt feel swings or hot spots. It
should stay the same temperature all the time regardless if its running or not
unless you are directly below or above a vent. If it gets really cold when the
unit kicks on then warms up after it kicks off then your unit is oversized
plain and simple.
--
for full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
Honestly there isnt one answer for every situation but your unit should run
enough to keep humidity at acceptable ranges. The person with the 800 sq ft
house is going to have issues with humidity due to size of house and 2.5 ton
is most likely oversized. Depending on insulation and windows your looking at
a 1.5 - 2 ton unit. Run cycles will change with the temperature outside as
well as humidity levels. Best thing to do is set indoor fan to circulating
mode if that option is available to keep air moving due to the size of the
house also you should be able to adjust speed if it sounds like a jet. There
are more options besides smaller system. The off cycle is going to be effected
by how well the house is insulated as well. If its not insulated well than
your house is going to heat up faster when the ac is off therefore ot will
cucle more often. Also I am not sure how much saving you anticipated on an
800sq ft house because ot doesnt use enough energy in the forst place to allow
for a noticeable change either way. If it were a 2500sq ft house with a $400
electric then you could expect a noticeable saving by updating to a newer and
more energy efficient system. Think of percentages when dealing with savings
also which means 10 percent of $100 is less than 10 percent of $400. Back to
run time....unit should be sized properly to have a long enough run time which
in my opinion is 5-10 minutes to properly remove humidity and off time should
be around 20-35 minutes. This varies because an old house will gain heat
faster than a new well insulated house. There is also room for error on sizing
due to all the variables and size of home which I always lean to the 1/2 ton
larger side for the abnormally high temps we experience for a week at a time
in southern Illinois. Never have had one issue with run times or humidity. My
last customer questioned it running every 30 minutes but he came from window
units and thought that was to much but you have to also factor in the comfort
throughout home which means a customer shouldnt feel swings or hot spots. It
should stay the same temperature all the time regardless if its running or not
unless you are directly below or above a vent. If it gets really cold when the
unit kicks on then warms up after it kicks off then your unit is oversized
plain and simple.
--
for full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
tsj...@gmail.com
May 14, 2019, 5:29:51 PM5/14/19
to
My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough. Last thing I want is a more $$. SRP bill shows $170 this month estimate thus far... That's with my normal 77 with 2 swing. Anyways I wanted to ask you guys how would you best handle this issue. Short cycling doesn't quite point to my issue I suppose to the letter. How old you guys handle this?.. not enough funds for new AC unit and not wanting crazy bulls either, but don't want to feel like I'm in a fireplace either. Thank you all for any ideas or suggestions on this. Bless.
trader_4
May 14, 2019, 5:59:20 PM5/14/19
to
On Tuesday, May 14, 2019 at 5:29:51 PM UTC-4, Dan wrote:
> My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough. Last thing I want is a more $$. SRP bill shows $170 this month estimate thus far... That's with my normal 77 with 2 swing. Anyways I wanted to ask you guys how would you best handle this issue. Short cycling doesn't quite point to my issue I suppose to the letter. How old you guys handle this?.. not enough funds for new AC unit and not wanting crazy bulls either, but don't want to feel like I'm in a fireplace either. Thank you all for any ideas or suggestions on this. Bless.
Why did you go from 77 with a 2 deg swing, to 76 with a 6 deg swing?
> My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough. Last thing I want is a more $$. SRP bill shows $170 this month estimate thus far... That's with my normal 77 with 2 swing. Anyways I wanted to ask you guys how would you best handle this issue. Short cycling doesn't quite point to my issue I suppose to the letter. How old you guys handle this?.. not enough funds for new AC unit and not wanting crazy bulls either, but don't want to feel like I'm in a fireplace either. Thank you all for any ideas or suggestions on this. Bless.
Why not pick something in between, like 3? I couldn't live with a 6 deg
swing. Also I don't understand if it was running 5 mins on, 17 off how
it could go to running 17 on and 15 off? That means it went from running
about 23% of the time to running 53% of the time? Something doesn't add
up, but if it's running that much, I see why you're concerned about
power usage. I'd settle for a compromise where it runs a little longer,
but still keeps the temp within an acceptable range. The disadvantage
to short cycling is it will use somewhat more energy and it's additional
wear on the compressor, fan etc with excessive starts, but I wouldn't
obsess over it either. It may not really affect the compressor life
that much, if at all. You don't say how old this system is, what the
operating costs are, etc. If it's old and inefficient, they payback
for a new right sized system might not be that long in AZ.
Ed Pawlowski
May 14, 2019, 9:51:13 PM5/14/19
to
On 5/14/2019 5:29 PM, tsj...@gmail.com wrote:
> My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough.
Something does not sound right. More run time will remove more moisture
> My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough.
and increase comfort. Of course as you already know an oversized unit
does not run as long to get the temperature down. More run time also
means higher cost.
The 6 degree swing will increase run time giving you at least temporary
comfort, but the off time would be increasingly getting uncomfortable.
It then has to work harder to get to the low setting. I think as long
as the AC is blowing dry air you feel comfortable.
As an aside, many years ago my father was the plant engineer at a
printing plant. Humidity control was important and on cool damp days it
would be very high. They would run the heat and AC at the same time to
maintain both temperature and low humidity. You can do that too, but
obviously it would be very expensive.
Dan
May 15, 2019, 3:06:01 PM5/15/19
to
The system is older... 9 years... house is 1100 square feet and the builder placed a 4 ton here.... yes 4 ton, and its way over sized of course.... hence my issues. have to make do as money is tight, so trying to be comfortable and yet save money and baby the ac. Sorry if my post is a bit confusing, i have been dealing with this for a long time to find that sweet spot and its driving us crazy...... thank you for your time.
Dan
May 15, 2019, 3:32:42 PM5/15/19
to
1 = .25
2 = .50
3 = .75
4 = 1
so when I did 6 swing at set 76 that would have been 77.5F
etc..
trader_4
May 15, 2019, 4:59:32 PM5/15/19
to
On Wednesday, May 15, 2019 at 3:06:01 PM UTC-4, Dan wrote:
> On Tuesday, May 14, 2019 at 2:59:20 PM UTC-7, trader_4 wrote:
> > On Tuesday, May 14, 2019 at 5:29:51 PM UTC-4, Dan wrote:
> > > My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough. Last thing I want is a more $$. SRP bill shows $170 this month estimate thus far... That's with my normal 77 with 2 swing. Anyways I wanted to ask you guys how would you best handle this issue. Short cycling doesn't quite point to my issue I suppose to the letter. How old you guys handle this?.. not enough funds for new AC unit and not wanting crazy bulls either, but don't want to feel like I'm in a fireplace either. Thank you all for any ideas or suggestions on this. Bless.
> >
> > Why did you go from 77 with a 2 deg swing, to 76 with a 6 deg swing?
> > Why not pick something in between, like 3? I couldn't live with a 6 deg
> > swing. Also I don't understand if it was running 5 mins on, 17 off how
> > it could go to running 17 on and 15 off? That means it went from running
> > about 23% of the time to running 53% of the time? Something doesn't add
> > up, but if it's running that much, I see why you're concerned about
> > power usage. I'd settle for a compromise where it runs a little longer,
> > but still keeps the temp within an acceptable range. The disadvantage
> > to short cycling is it will use somewhat more energy and it's additional
> > wear on the compressor, fan etc with excessive starts, but I wouldn't
> > obsess over it either. It may not really affect the compressor life
> > that much, if at all. You don't say how old this system is, what the
> > operating costs are, etc. If it's old and inefficient, they payback
> > for a new right sized system might not be that long in AZ.
>
> Thanks. The 5 minutes run was when it was 77 with 2 swing. Seeing that isn't much run time, i changed it to 76 with 6 swing to increase runtime.. which it worked, ran 17-20 minutes. why 76, well we want to keep house at 77, so to simulate that yet allow more run, i did 76 with 6 swing, which should place it at 77.5.
I don't understand that math. Doesn't 6 swing mean it turns on when it's
> On Tuesday, May 14, 2019 at 2:59:20 PM UTC-7, trader_4 wrote:
> > On Tuesday, May 14, 2019 at 5:29:51 PM UTC-4, Dan wrote:
> > > My situation even tho it would appear to be short cycling isn't quite accurate. My issue is run time. Typically as if now in AZ it's 90 pit and run time is 5 minutes and off time 17. So this truly by definition wouldn't be short cycling would it?. Anyways I've known for years system is indeed oversized and tried to compensate with my lux swing settings. Usually kept set at 2 with set at 77. It's just becoming uncofortable though as temps per display shows 78 when it comes on even though should be 77.50. Anyways today I'm trying something new, set temp for 76 with a 6 swing. Run time now is 17 minutes with off being around 15. Air feels much more comfortable yet worried now on $$ as times are tough. Last thing I want is a more $$. SRP bill shows $170 this month estimate thus far... That's with my normal 77 with 2 swing. Anyways I wanted to ask you guys how would you best handle this issue. Short cycling doesn't quite point to my issue I suppose to the letter. How old you guys handle this?.. not enough funds for new AC unit and not wanting crazy bulls either, but don't want to feel like I'm in a fireplace either. Thank you all for any ideas or suggestions on this. Bless.
> >
> > Why did you go from 77 with a 2 deg swing, to 76 with a 6 deg swing?
> > Why not pick something in between, like 3? I couldn't live with a 6 deg
> > swing. Also I don't understand if it was running 5 mins on, 17 off how
> > it could go to running 17 on and 15 off? That means it went from running
> > about 23% of the time to running 53% of the time? Something doesn't add
> > up, but if it's running that much, I see why you're concerned about
> > power usage. I'd settle for a compromise where it runs a little longer,
> > but still keeps the temp within an acceptable range. The disadvantage
> > to short cycling is it will use somewhat more energy and it's additional
> > wear on the compressor, fan etc with excessive starts, but I wouldn't
> > obsess over it either. It may not really affect the compressor life
> > that much, if at all. You don't say how old this system is, what the
> > operating costs are, etc. If it's old and inefficient, they payback
> > for a new right sized system might not be that long in AZ.
>
> Thanks. The 5 minutes run was when it was 77 with 2 swing. Seeing that isn't much run time, i changed it to 76 with 6 swing to increase runtime.. which it worked, ran 17-20 minutes. why 76, well we want to keep house at 77, so to simulate that yet allow more run, i did 76 with 6 swing, which should place it at 77.5.
3 over and off when it's 3 under? That would still average it at 76.
The off time tho is quite large. Just trying to find a happy medium where it will run longer to condition air better, yet not kill us in $$ or tax the machine to much.
house at the same average temperature.
from all i read to properly work efficiently it needs to run 10 minutes or more... Our air always feels well not crisp in the house, hence why also i changed it to run longer and that has worked.. but the off time is rough....
>
> The system is older... 9 years... house is 1100 square feet and the builder placed a 4 ton here.... yes 4 ton, and its way over sized of course....
hence my issues. have to make do as money is tight, so trying to be comfortable and yet save money and baby the ac. Sorry if my post is a bit confusing, i have been dealing with this for a long time to find that sweet spot and its driving us crazy...... thank you for your time.
more temp fluctuation for run time.
Dan
May 15, 2019, 5:14:19 PM5/15/19
to
Swing Setting
1 +\- .25 F
2 +\- .5 F
3 +\- .75 F
4 +\- 1.0 F
5 +\- 1.25F
6 +\- 1.5 F
7 +\- 1.75 F
8 +\- 2.0 F
9 +\- 2.25 F
Example: For tightest control, set swing setting on # 1 which is plus or minus .25 degrees F. If you set the setpoint at 70 F, the highest it will get to is 70.25 F, the lowest it will get to is 69.75
Example: On swing setting # 8, if setpoint is at 70 with swing of plus or minus 2 F. Highest it will go to is 72 and lowest it will go to is 68 F.
the only reason I went to 76 from 77 is a swing set from a set 77 gets to warm in here... as a swing from that set is taking me into 78+ territory (assuming i want longer run times) .. hence why i went to 76 and did swing from that point so we can get longer run times, yet remain under 78.
Not sure if this the right way to do it.... yet my circumstances here arent ideal. the stat is even in the hall way below the return vent... horrible placement causing issues there in its own right. I have been looking at those stats that allow me to have a sensor in another room, would love for it to be in the living room and not in the hall with the return vent.
George
May 15, 2019, 8:21:24 PM5/15/19
to
On 5/15/2019 4:59 PM, trader_4 wrote:
> The off time tho is quite large. Just trying to find a happy medium where it will run longer to condition air better, yet not kill us in $$ or tax the machine to much.
>
> There shouldn't be much difference in cost if it's still keeping the
> house at the same average temperature.
I run a separate dehumidifier to remove the humidity and let the central AC run as needed to regulate the temperature.
> The off time tho is quite large. Just trying to find a happy medium where it will run longer to condition air better, yet not kill us in $$ or tax the machine to much.
>
> There shouldn't be much difference in cost if it's still keeping the
> house at the same average temperature.
Run a ceiling fan and you can set the AC thermostat higher and still be comfortable.
CRYSTAL
Aug 16, 2021, 2:15:07 PM8/16/21
to
I just got a new ac unit installed i set the thermostat on 70 well it don't feel like 70degrees and it will cut on and run for exactly 3minutes and stays off for 20minutes before coming back on for 3min can someone please help me on what you think it could be please
--
For full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
--
For full context, visit https://www.homeownershub.com/maintenance/normal-a-c-on-off-cycle-durations-128958-.htm
Ed Pawlowski
Aug 16, 2021, 3:37:54 PM8/16/21
to
On 8/16/2021 2:15 PM, CRYSTAL wrote:
> I just got a new ac unit installed i set the thermostat on 70 well it
> don't feel like 70degrees and it will cut on and run for exactly
> 3minutes and stays off for 20minutes before coming back on for 3min can
> someone please help me on what you think it could be please
>
Could be a lot of things. Bad thermostat, not properly charged system,
> I just got a new ac unit installed i set the thermostat on 70 well it
> don't feel like 70degrees and it will cut on and run for exactly
> 3minutes and stays off for 20minutes before coming back on for 3min can
> someone please help me on what you think it could be please
>
something overheating, Oversized system. What is the thermometer reading?
If it was just installed, call the company back and let them sort it
out. You paid for a proper system, let them fix it.
Larry
Aug 16, 2021, 3:38:32 PM8/16/21
to
On 8/16/21 2:15 PM, CRYSTAL wrote:
> I just got a new ac unit installed i set the thermostat on 70 well it don't feel like 70degrees and it will cut on and run for exactly 3minutes and stays off for 20minutes before coming back
> on for 3min can someone please help me on what you think it could be please
>
Maybe you should ask the install company?
> I just got a new ac unit installed i set the thermostat on 70 well it don't feel like 70degrees and it will cut on and run for exactly 3minutes and stays off for 20minutes before coming back
> on for 3min can someone please help me on what you think it could be please
>
trader_4
Aug 16, 2021, 5:08:04 PM8/16/21
to
it feels like is one thing, but what does the thermostat actually read?
What temp is it really? If it's 70 and doesn't feel like 70, could be it's
humid and they need to lower it to 68F.
Tekkie©
Aug 16, 2021, 5:12:17 PM8/16/21
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On Mon, 16 Aug 2021 18:15:02 +0000, CRYSTAL posted for all of us to digest...
>
> I just got a new ac unit installed i set the thermostat on 70 well it don't feel like 70degrees and it will cut on and run for exactly 3minutes and stays off for 20minutes before coming back on for 3min can someone please help me on what you think it could be please
thermostat is bad or mis-located.
--
Tekkie
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