Before I go buy a basement dehumidifier unit to at least protect my
gear, what other solutions could I look at? The guy who installed it
doesn't have answers. He says it should only add 15% of humidity and
clearly it's blowing past that. He hasn't come up with any other
answers. Just shooting this out there before I spend $300-400 on a
portable dehumidifier unit for my basement.
Humidity is related to temperature. You should be able to find a table
that tells you what outside air humidity would be if you brought it
inside and cooled to inside temperature. Central air conditions working
as heat pumps automatically dehumidify air. I'm not familiar with
evaporative systems, but guess they don't.
Frank
> last summer. Same thing this summer. The other problem is the
> negative effect on my guitars from the huge swings in the humidity.
> So typically the humidity in my area is between 20-30% on average
> during the summer. During that outside humidity, my home is getting
> up to between 60-70%. Holy smokes! That's high and I cannot for the
> life of me figure out why my house is loading up with that much
> humidity. Anyone else see this with their situation?
Because you are pumping it in there with an evaporative cooler, that's how
they work, they lower the temp by increasing the humidity. Have you tried
leaving a few windows open?
>
> Before I go buy a basement dehumidifier unit to at least protect my
> gear, what other solutions could I look at? The guy who installed it
> doesn't have answers. He says it should only add 15% of humidity and
> clearly it's blowing past that. He hasn't come up with any other
> answers. Just shooting this out there before I spend $300-400 on a
> portable dehumidifier unit for my basement.
If leaving some windows open doesn't help lower the humidity, then I would
buy an A/C(which is what dehumidifier is anyway, just that the A/C dumps the
heat outside not back inside like the dehumidifier does). I doubt a
dehumidifier would do much to lower humidity in a room cooled by an
evaporative cooler anyway.
A dehumidifier with an evaporative cooler is just one thing fighting another.
Get an A/C, which is just a dehumidifier that dumps the heat outside instead of
inside.
Replying to a couple here....
I have no ductwork in my house so I have nothing to deliver AC to all
parts of the home. My swamp cooler is on the roof and one large duct
runs to the main return which is positioned at the end of the hallway
on the top of of a 2-floor/basement setup. From my understanding of
AC, I could cool the upstairs pretty well, but would it cool the
middle floor? Basement doesn't matter as it stays cool.
Regarding my current setup, I am opening windows when running the
swamp cooler. I'm going to try opening up more windows around the
house to improve the flow and see if that takes down the humidity.
One last option I'm considering is buying some climate control cases/
display case for my guitars. It's going to depend on the costs of
changing out my evap cooler.
~~~~~~~~~~~~~~~~~~~~~~~~~~
Airflow and cooling from that evaporative system depends on equalizing the
area of exit air openings to the incoming air. The placement of the exiting
air openings determine where the cool air travels and thus how much of the
space gets cooled. Convection says open a window at the top of the space and
one in the basement and the hot air will exit the top while cooler air is
drawn into the space from the basement. Evaporative coolers work opposite
convection. Cool air is forced into the top of the space and an equal amount
must be allowed to escape from the bottom. Progressively larger openings
from the top to the bottom will better "zone" the cooling effect. If one
area is hot on one floor, open a pathway for cool air to exit that hot area
to the outside. If your air handler moves 3 tons into the house you must
allow 3 tons to escape or your air handler will just sit there and
pressurize your house without doing much cooling.
The above convoluted paragraph might need pictures so. I did a google and
found this page for you.
http://www.consumerenergycenter.org/home/heating_cooling/evaporative.html
--
Don Thompson
Stolen from Dan: "Just thinking, besides, I watched 2 dogs mating once,
and that makes me an expert. "
There is nothing more frightening than active ignorance.
~Goethe
It is a worthy thing to fight for one's freedom;
it is another sight finer to fight for another man's.
~Mark Twain
Outside temperature and humidity
Inside temperature and humidity
Temperature and humidity of the air exiting your evap cooler.
Air velocity and volume flow through your evap cooler.
Ideally, you'd get one or more of those little weather stations that can log
data to your PC so that I could see trends.
In the absence of data, some discussion.
Evaporative cooling works by turning sensible heat (what you can feel) into
latent heat of evaporation. To accomplish that, it has to evaporate the water
and that water goes into your air as humidity.
There is a "comfort zone" as quantified by ASHRAE, of temperature and humidity
over which most people are comfortable. One can tolerate a higher temperature
if the humidity is low and vice versa. You might google for "ASHRAE comfort
zone" to learn more.
Evaporative cooling depends on the outside temperature and particularly
humidity being low enough so that after the water is evaporated, the resulting
temperature and humidity are still within the comfort zone.
If the temperature outside is too high then the evaporative process may not
reduce the temperature enough for the air to be comfortable at the resulting
humidity. If the humidity is high enough outside then even cool air will not
be comfortable (clammy) and air that would be comfortable at lower humidity
will be muggy.
The heart of the human comfort zone and that of most indoor furnishing is 50%
humidity, plus a little, minus a bit more. For example, I'm sitting here
looking at my indoor weather station and see that it is 70 degrees and 49%
humidity. I'm as comfortable as a clam in sauce :-)
Sixty percent humidity is in the clammy-to-muggy range. Seventy percent is
far into that range. That is, you won't be truly comfortable at any
temperature with the humidity that high. Additionally, this much humidity
will encourage mold and fungus growth inside your house. What that tells me is
that the outside humidity is too high for evaporative cooling to work.
This problem can be addressed in several ways. The most direct is to install
an AC system and perhaps a smart environmental control unit (thermostat) that
will transfer back and forth from the evap to the AC depending on outside
conditions. The AC can be made more efficient by putting an evaporative
cooler in front of the condenser air intake. In fact, it could approach the
efficiency of the evap alone.
Another possible solution is to conduct the output of the evap through an
air-to-air heat exchange. This allows the heat from the interior to be
conduced to the evaporatively cooled air but keeps the evaporated water out of
your house. A/A exchangers are standard HVAC components.
Another A/A exchanger would probably be necessary to circulate fresh air into
the house. This system has outgoing air flowing over one side of the
exchanger and incoming air flowing over the other. The "coolth" from the
outgoing air is recovered and cools the incoming air.
Really smart AC units have the ability to use outside "tempering air". That
is, a little computer built into the unit measures the outside temperature and
humidity and, knowing the energy demand curve of the AC and the inside
conditions, opens or closes dampers to let more or less outside air in. This
feature can dramatically lower the cost of operation. This is a standard
feature on commercial units.
You could build a small 'dry room' for your musical instruments and other
humidity-sensitive things but that won't solve the problem of you being
uncomfortable, nor the negative effect high humidity has on everything else.
Seeing how far apart we are geographically , remote engineering of your system
probably isn't practical. I therefore suggest that you find a competent HVAC
man or even an HVAC engineer and have him address your problem. Post their
proposals here and I'll critique them.
One other comment. It seems that both temperature and humidity have been
slowly rising for decades (no, not global warming, natural weather cycles). It
certainly has here. I've owned this cabin that I now live in since 1970 and
was fine during the summer until about 5 years ago. Now it gets so hot and
humid that everyone here has AC. My cabin would be uninhabitable without it.
My neighbor who is a weekend resident held out the longest but last spring I
helped him install an AC system in his cabin.
It's very possible that your evap may no longer be practical, at least not all
the time. You may have to install an AC to handle the worst of the summer and
rely on the evap at other times.
John
On Wed, 23 Jul 2008 10:26:15 -0700 (PDT), Mtmartin71 <mtmar...@hotmail.com>
wrote:
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
You can't turn [MS] shovelware into reliable software by patching it a whole lot. -Marcus Ranum
Thanks for your extensive and thorough answers. I decided earlier
today to call an HVAC specialist and discuss some other options for my
home. He's coming in next week and I'll share some of the info you
had (as well as posting what he is proposing). I think the net is
that I need to fix my overall cooling system rather than to find
something to protect my equipment. At a minimum, I can run my
cooler's fan without the wet pad and just use it to circulate cold air
through my house at night to get some comfortable sleep. In that
sense, it kind of operates like a whole house fan but in the reverse
fashion of what I used to use. I do need to stop putting the humidity
in my house though and probably need to make sure I'm not getting
mildew issues already.
Thanks,
Matt
John,
I live near enough the OP to have a good idea what the climate conditions
are in general. The humidity levels in the Denver metro area have been going
up over the 20 years I have owned my house but the RH in the summertime
rarely goes over 25% in the daytime often as low as 8 - 12%. Overnight the
RH sometimes goes up to ~ 50% but the outside temperature drops from 98 F.
to 65 F. and often into the 50's F. Until this year I used a "Whole House"
fan along with ceiling fans to cool the place, running it from just before
sundown until 10 Am or so before I closed the windows and turned off the
"Whole House" fan. Many mornings, even in Aug., the house was cool enough to
require a light blanket during the night. Things change. Retirement and
medical condition demands cooler air on a reliable basis so I installed an
expensive but supposedly "efficient" 16.5 SEER AC with a +95% furnace HVAC
system last spring. Comfort level is up and so is electrical cost but
surprisingly, even with the fuel surcharges, I am actually paying only
slightly more than last year. The AC uses less electricity than running 7
fans did.
I think the OP's problem was/is a combination of insufficient airflow
through the house, insufficient waterflow over the pads/heavily deposit
covered pads, and perhaps his evaporative unit is trying to pull excessively
hot, unshaded rooftop air in and cool it more than is possible. In my
neighborhood there are a lot of "Swamp Cooler" boxes on rooftops and the
folks using them seem pretty satisfied.
My experience has been that swamp coolers usually work well (in Utah)
without delivering excessive amounts of humidity to the house.
However, it seems like there is always at least one period during the
summer when humidity outside becomes very high and when that happens
humidity inside becomes high also. It does seem like these periods
happen more often than they did 20-30 years ago, for example, and when
they happen it also seems like they last longer than they used to.
There are two things you can try that might minimize the problem a
little bit. One of them is to get an attic fan installed. That will
reduce the need for the swamp cooler. If you don't want to do that,
then I would suggest you have some large vents put on top of your
roof.
Another idea would be to put an electronic thermostat on your
evaporative cooler (if you haven't done so already). That will
minimize how often the swamp cooler comes on. With an electronic
thermostat you can also play with it a little bit in order to find a
compromise temperature to set it at versus outside humidity and
outside temperature. If the outside humidity is 35%, for example, and
the thermostat is set to 69 degrees, the swamp cooler might run all
day without being able to cool to that temperature. But if you set it
to 72 degrees, the swamp cooler might only kick on occasionally.
>John,
>
> I live near enough the OP to have a good idea what the climate conditions
>are in general. The humidity levels in the Denver metro area have been going
>up over the 20 years I have owned my house but the RH in the summertime
>rarely goes over 25% in the daytime often as low as 8 - 12%. Overnight the
>RH sometimes goes up to ~ 50% but the outside temperature drops from 98 F.
>to 65 F. and often into the 50's F. Until this year I used a "Whole House"
>fan along with ceiling fans to cool the place, running it from just before
>sundown until 10 Am or so before I closed the windows and turned off the
>"Whole House" fan. Many mornings, even in Aug., the house was cool enough to
>require a light blanket during the night. Things change. Retirement and
>medical condition demands cooler air on a reliable basis so I installed an
>expensive but supposedly "efficient" 16.5 SEER AC with a +95% furnace HVAC
>system last spring. Comfort level is up and so is electrical cost but
>surprisingly, even with the fuel surcharges, I am actually paying only
>slightly more than last year. The AC uses less electricity than running 7
>fans did.
Thanks Don. You highlight the problem of trying to do this remotely without
any data to work with. BTW, you might consider setting up a swamp cooler to
feed the condenser of that AC. In older units I've seen the power draw (not
just amps) drop almost by half by simply putting a cooler pad in front of the
air intake. It doesn't gain you so much on high SEER units but it still might
be worth it. Just rig up a water connection with a solenoid valve to keep the
pad wet. Open the valve with the same signal that closes the compressor
contactor.
I've set up many such arrangements, taking the water from an outside faucet if
the owner wanted it done cheap. Even here in the humid South, the improvement
can be remarkable.
>
> I think the OP's problem was/is a combination of insufficient airflow
>through the house, insufficient waterflow over the pads/heavily deposit
>covered pads, and perhaps his evaporative unit is trying to pull excessively
>hot, unshaded rooftop air in and cool it more than is possible. In my
>neighborhood there are a lot of "Swamp Cooler" boxes on rooftops and the
>folks using them seem pretty satisfied.
You're probably right, though I worry some about the humidity if it does rise
into the 30s. That's getting close to the edge of the comfort zone.
Speaking of roof mounts, that's something that I've been curious about. Why
are swamp coolers mostly mounted on the roof where all the hot air is? It
would seem much better to mount it near the ground on the North side where the
sun wouldn't hit it very often and the air would be cooler. I have seen some
mounted up high on the outside of the gable. Even that's better than the roof
mount, one would think.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
If stupidity hurt then they'd be putting morphine in the water supply.
A few quick points to Don's thougths and yours....
While my evap cooler is on the roof, it is blocked from the heat of
the day by an enormous cottonwood tree in front of my house. It's a
south facing home and the cooler is on the north end of the roof
behind this tree. It's still hot on the roof, but it is not getting
beat on by the sun. As far as the pad being filled with deposits,
that would seem to indicate the cooler not working or less moisture
getting into the house. That doesn't seem to be the problem. My
basement got up to 80% humidity just a few days ago. I decided to
just stop using the thing and now it's dropping down to under 70% in
just a day's time. Hopefully I can dry it out to around 50% at least.
I think I just need a different form of cooling for my home. I can at
least use my cooler fan with no moisture drip to blow colder air
through the house at night until I come up with an alternative.
Matt
> you might consider setting up a swamp cooler to
> feed the condenser of that AC. In older units I've seen the power
> draw (not just amps) drop almost by half by simply putting a cooler
> pad in front of the air intake. It doesn't gain you so much on high
> SEER units but it still might be worth it. Just rig up a water
> connection with a solenoid valve to keep the pad wet. Open the valve
> with the same signal that closes the compressor contactor.
>
> I've set up many such arrangements, taking the water from an outside
> faucet if the owner wanted it done cheap. Even here in the humid
> South, the improvement can be remarkable.
>
>
Thanks, that is just the confirmation of what I was looking for.
How does one set it up?
--
SneakyP
To reply: newsgroup only, what's posted in ng stays in ng.
Some choose to swim in the potty bowl of nan-ae rather than flush it
down :0)
<snip>
>
> Thanks Don. You highlight the problem of trying to do this remotely
> without
> any data to work with. BTW, you might consider setting up a swamp cooler
> to
> feed the condenser of that AC. In older units I've seen the power draw
> (not
> just amps) drop almost by half by simply putting a cooler pad in front of
> the
> air intake. It doesn't gain you so much on high SEER units but it still
> might
> be worth it. Just rig up a water connection with a solenoid valve to keep
> the
> pad wet. Open the valve with the same signal that closes the compressor
> contactor.
>
> I've set up many such arrangements, taking the water from an outside
> faucet if
> the owner wanted it done cheap. Even here in the humid South, the
> improvement
> can be remarkable.
>
Good idea with another benefit. Damp pads would keep cottonwood fluff and
other clogging debris out of the fins on the condenser coil. Both a cooling
and filtering effect.
>>
>> I think the OP's problem was/is a combination of insufficient airflow
>>through the house, insufficient waterflow over the pads/heavily deposit
>>covered pads, and perhaps his evaporative unit is trying to pull
>>excessively
>>hot, unshaded rooftop air in and cool it more than is possible. In my
>>neighborhood there are a lot of "Swamp Cooler" boxes on rooftops and the
>>folks using them seem pretty satisfied.
>
> You're probably right, though I worry some about the humidity if it does
> rise
> into the 30s. That's getting close to the edge of the comfort zone.
>
> Speaking of roof mounts, that's something that I've been curious about.
> Why
> are swamp coolers mostly mounted on the roof where all the hot air is? It
> would seem much better to mount it near the ground on the North side where
> the
> sun wouldn't hit it very often and the air would be cooler. I have seen
> some
> mounted up high on the outside of the gable. Even that's better than the
> roof
> mount, one would think.
>
Cost of installation I think. Roof mounting allows the incoming air a
straight down, pretty much unobstructed, short, path into the house. As you
know, bends in the airstream cause high friction losses to the flow and
effectively lengthen the duct. Longer ducting requires more power to get the
same volume and velocity of air at the outlet and whole house evaporative
cooling depends on high airflow to both keep the house cool and the humidity
tolerable.
Matt
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Couple of thoughts.
Perhaps that cooler is saturated with Cottonwood fluff restricting airflow?
Are there any other filters in the system that might need cleaned/changed
out?
Deposits on the pad wouldn't make the cooler not work at all, just reduce
the efficiency of the heat exchange mechanism by reducing the surface area
of water exposed to the airflow. High airflow over a smaller surface will
tend to yank larger amounts of water into the wind stream. If the blower is
pulling air through smaller and smaller openings the velocity of the air
will increase through the openings to make up for the volume demanded and
you may not notice the airflow problem until the humidity problem becomes
acute. I use "Denver Water" and the stuff leaves behind a quite heavy layer
of evaporites. Before you throw a lot of money into the thing maybe climb up
on the roof after running the unit "dry" for a few days and look at the
pads. If they are as deposited as I think they might be you can go to "Home
Depot" and buy replacement pads.
>Neon John <n...@never.com> wrote in
>news:7tqj845akkqqgd87t...@4ax.com:
>
>> you might consider setting up a swamp cooler to
>> feed the condenser of that AC. In older units I've seen the power
>> draw (not just amps) drop almost by half by simply putting a cooler
>> pad in front of the air intake. It doesn't gain you so much on high
>> SEER units but it still might be worth it. Just rig up a water
>> connection with a solenoid valve to keep the pad wet. Open the valve
>> with the same signal that closes the compressor contactor.
>>
>> I've set up many such arrangements, taking the water from an outside
>> faucet if the owner wanted it done cheap. Even here in the humid
>> South, the improvement can be remarkable.
>>
>>
>Thanks, that is just the confirmation of what I was looking for.
>
>How does one set it up?
Depends on what tools you have available. I had access to a sheet metal shop
so I made sheet metal pieces to hold the mats in place a couple of inches in
front of the condenser air intake. Or in the case of wrap-around condensers,
several pads. The top bracket was also the trough that distributed the water
to the pad via holes punched in it.
You could do the same thing with wood. Redwood is the traditional material
used to make cooling towers and other structures that are always wet. Just
make a box frame to hold the pads and some method of distributing the water to
the top of the pad. A length of PEX tubing with a series of tiny holes either
drilled or burned with a hot paperclip or something will do fine.
Make it easy to remove the pads, as they crud up fairly rapidly even with soft
water. The crud comes from the air. I've tried both the hair-like pads and
the corrugated cardboard pads. I like the cardboard better.
One thing that you have to watch for is to keep the air velocity low enough
that it doesn't pull liquid water from the pad and into the condenser. Even
if the water is dead-soft, crap from the air dissolves in the water and when
it dries in the condenser, leaves crud. This crud will build up until the
condenser is stopped up. It also corrodes the fins.
if the velocity is too high when simply mounting a pad in front of the
condenser then you'll need to build a funnel affair that flares out so that a
larger pad can be used. Again, doable in wood but much easier with sheet
metal.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
You have a magnetic personality... That must be why all your mental floppies are blank.
I've done a cheap/fast one using 2 water misting nozzles set-up to spray at
180degrees to the airflow. It drops the current by about 20%. I'm not sure
my kill-o-watt "like unit" could handle any start up surge so I cant measure
what the PF does. I did monitor the entire house using the house meter for a
few hours, from memory the kWhr drops by 5-10% .
Water misting nozzles use about 2 gallons an hour each(so the box says I
haven't measured that).
As NJ says you need to be careful with water hitting the condenser, but the
water is very clean and soft where I live, also the design of the unit
splashes the condensate water over the condenser anyway. As its only a large
wall mounted unit I took a chance. I haven't noticed any crud build up yet.
It is a wall mounted unit connected to a ducted heating system so is a
little undersized for the house. It is therefore running flat out most of
the time that it is on so I haven't bothered with valves etc.
Mtmartin71 wrote:
> Cutting to the chase, I live in the Denver, CO area in a house that
> does not have ducts and is heated by hot water heat and cooled (as of
> last summer) by a nice, professional installed evaporative cooler. I
> noticed the house felt too humid, especially the basement, most time
> last summer. Same thing this summer.
That's how they work I'm afraid.
You need a /c.
Graham
Any idea what the actual difference in air temperature would be?
I like this idea of putting an evaporative cooler around the condenser.
I live in the panhandle of Fl.
Is the feasible in my area?
Mike
Unlikely to do you much good because (I believe) you live in a high humidity
area. I have seen various schemes for installing low volume misters with a
water valve that only opens when the compressor is on, but that would help you
much less in a high humidity area, and the moisture could cause problems such as
rust or mold.
Vaughn
>> This problem can be addressed in several ways. The most direct is to
>> install
>> an AC system and perhaps a smart environmental control unit (thermostat)
>> that
>> will transfer back and forth from the evap to the AC depending on outside
>> conditions. The AC can be made more efficient by putting an evaporative
>> cooler in front of the condenser air intake. In fact, it could approach
>> the
>> efficiency of the evap alone.
>
> I like this idea of putting an evaporative cooler around the condenser.
>I live in the panhandle of Fl.
> Is the feasible in my area?
Dunno. How's the humidity there? It's so cheap to try that maybe you could
just give it a shot and see what happens. Just lash something together with
duct tape and bailing wire and run it for a month or two and see what your
bill looks like. Not very scientific but if you see a big difference right
off the bat then you know that it's worth getting a bit more sophisticated
with.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Remember, amateurs made the Ark, professionals made the Titanic.
Testing it for myself.
http://farm4.static.flickr.com/3180/2741932305_f9aaef1620_b.jpg
I've gotten the pad from a hobby crafts store. It is a 2" thick poly
used to stuff furniture seat pads outdoors. The foggers are from Home
Depot, found in the sprinkler section in the piping area. I have a
thermometer sensor on the inside just to see what cooling is accomplished
(white wire). It works somewhat well (considering our FL panhandle
humidity). What I've seen is that the foggers will mist the outside part
of the pad which collects water droplets. I'm not sure how deep they
impregnate the pad but I might try dripping water from the top of the pad
to see if this improves the performance.
Yeah, I may build a bigger rig to surround the AC unit with. Maybe
chicken wire would be a cheap form to build upon.
I'll update with figures.
I had the same concern about that poly. Further, I wonder if you really need
the poly at all. It seems to me like just the misters would provide any benefit
that you were going to get. (The poly might save you from losing some of the
water, and might afford the opportunity to use condensate water rather than
potable water). Evaporation from the mist would cool the immediate area, and
whatever droplets got sucked in would probably change phase in the vicinity of
the coils.
You do have a solenoid valve on the misters right? If not, strip one from
the back of a junk washing machine (120 VAC coil) or buy an irrigation valve at
Home Despot (24 VAC coil)
I will be interested in your results. I have thought of trying this myself,
but my guess is that there is a good reason why swamp cooled AC condensers are
not common, especially in Florida.
Vaughn
I plan on adding a valve soon.
The foggers are listed at .9gal/hr and rated for 40 to 80 psi. Doubt
they're pressurized that much off of the tap, so water usage is not
*that* high. Even with the higher humidity, it looks like the spray still
provides some cooling to the coil and the AC doesn't run continuously
like it once did. I would like to meter the current usage but don't have
a way to measure it directly. Incidentally, the condensate water dumps
right there so maybe there is a way to use that too.
Hmmm...
** Posted from http://www.teranews.com **
>
>
>
> --
> SneakyP
> To reply: newsgroup only, what's posted in ng stays in ng.
>
> Some choose to swim in the potty bowl of nan-ae rather than flush it
> down :0)
** Posted from http://www.teranews.com **
I have a window air conditioner whose condensate collects into a pan,
the fan when pan is full splashes condensate onto coil...believe this is
to increase efficiency....
hope helps...have fun.....sno
Yep, that is how they work these days. Neither of my window units ever seems
to drip condensate outside. Apparently it is all evaporated within the unit.
Vaughn