Cooling Cost
James
live.
I had the window fan on for 14 hours consumed 70Kw. Had the AC on 1
hour for 40 to 50Kw. One hour of AC didn't lower the temperature but
took moisture out of the air. It was pretty humid overnight and I was
able to lower the house from 82 to 76 after 14 hours.
The night before I had the AC on instead and that took 240Kw.
Based on this one observation it seems cheaper to use window fan at
night to cool my house.
Vic Smith
If you stick you hand outside and find the air considerably cooler
than inside the house, fans will usually suffice.
Some people never open a window and run their A/C 24/7.
Wasteful, except they save the physical effort of effort of checking
the temp, and opening/closing windows.
This is aside from the humidity issue you mentioned.
Some claim allergies of course.
--Vic
Gary Heston
James <j006...@hotmail.com> wrote:
>Overnight lows are usually around 70 even after 90+ highs where I
>live.
>I had the window fan on for 14 hours consumed 70Kw. [ ... ]
Your fan pulls 5000 watts? That's a really big fan. I think your
numbers are a bit off...
Gary
--
Gary Heston ghe...@hiwaay.net http://www.thebreastcancersite.com/
Why is it that these days, the words "What idiot" are so frequently
followed by the words "at Microsoft"?
James
> In article <5db0fc04-4a6a-4255-91c6-728a444d3...@56g2000hsm.googlegroups.com>,
>
> James <j0069b...@hotmail.com> wrote:
> >Overnight lows are usually around 70 even after 90+ highs where I
> >live.
> >I had the window fan on for 14 hours consumed 70Kw. [ ... ]
>
> Your fan pulls 5000 watts? That's a really big fan. I think your
> numbers are a bit off...
>
> Gary
>
> --
>
> Why is it that these days, the words "What idiot" are so frequently
> followed by the words "at Microsoft"?
Instead of Kw use units. I'll have to check the meter to see what's a
unit. It's probably 500 watts including fridge & lights, TV, etc.
JR Weiss
>
> I had the window fan on for 14 hours consumed 70Kw. Had the AC on 1
> hour for 40 to 50Kw. One hour of AC didn't lower the temperature but
> took moisture out of the air. It was pretty humid overnight and I was
> able to lower the house from 82 to 76 after 14 hours.
?!? I think you need to brush up on your math and electrical terms...
First, KW or KiloWatt is an energy consumption RATE. Electrical consumption is
measured in KWH or kilowatt-hours, which is the product of the consumption rate
and consumption time.
Second, I don't know where you got a window fan that consumes 5000 Watts (70 KWH
/ 14 hours) or 41.7 amps at 120 Volts. I doubt you have a circuit in your house
that can handle that!
You MIGHT have a fan that consumes 500 Watts, which would make for 7 KWH in 14
hours...
Then there's the AC... 45 KW is over 187 amps at 240 volts. I really doubt
that you have that kind of circuit in a house... Like the fan, i suspect you
have to divide by 10 again to get a realistic figure (4-5 KWH)
> The night before I had the AC on instead and that took 240Kw.
> Based on this one observation it seems cheaper to use window fan at
> night to cool my house.
Depends on what you define as "cool"...
You put up with 86+ deg and high humidity with the window fan running all day.
That means you could EASILY put up with 88-90 deg with low humidity by running
the AC. There's no real need to cool the house to 76!
When I lived in south TX, I kept the AC set at 82-84 deg. That was plenty cool
after coming out of the heat!
Jeff
> Overnight lows are usually around 70 even after 90+ highs where I
> live.
>
> I had the window fan on for 14 hours consumed 70Kw. Had the AC on 1
> hour for 40 to 50Kw. One hour of AC didn't lower the temperature but
> took moisture out of the air.
Well, that's not good.
It was pretty humid overnight and I was
> able to lower the house from 82 to 76 after 14 hours.
>
> The night before I had the AC on instead and that took 240Kw.
>
> Based on this one observation it seems cheaper to use window fan at
> night to cool my house.
As others have pointed out, your numbers are crazy.
Now, a fan pulling in cooler air at night is a good thing. But it is
rarely sufficient. Only you know how fast it takes your house to heat up.
I'd like to point out that fans are big energy users and leaving one
on does use energy. One of the big features of Energy Star ACs is that
they have a mode to cycle the fan off when the compressor is not
running. That saves a lot of energy, from not having the fan run
continuously.
Also, because it is cooler at night, your window AC will take less
energy to cool. It should cycle off much more.
Ideally, you'll want a mix of both ventilation and AC. But, if I had
to choose only one it would be AC.
In a poorly insulated home, the best way to save money is insulation.
You may also wish to do something with your windows if you have a lot of
solar gain. And do something with your attic, if your attic temps are high.
I've dramatically cut my cooling cost by adding insulation (all the
way around) and by switching to Energy Star ACs with a good EER. I'm
also much more comfortable.
It sounds like you have central air. The new outdoor units have much
higher SEERs than the old. I believe 16 is now common and 19s are out
there. You may wish to consider an upgrade there but the payback would
be multiple years.
Jeff
Jeff
There's some caveats on high SEER, particularly in very hot climates.
More here:
http://www.udarrell.com/air-conditioning-total-heat-enthalpy-latent-heat.html
Jeff
>
> Jeff
>