Re: Efficient use of Air conditioner

From: greywolf42 (mingstb_at_marssim-ss.com)
Date: 07/20/04 

Date: Tue, 20 Jul 2004 08:58:47 -0700

tom <tomairc@hotmail.com> wrote in message
news:6cf9dc02.0407200628.3f2a8a8b@posting.google.com...
> Can not convince wife about two things. Just want to bring it here for
> a serious judgement:
>
> 1. Use Air conditioner for home at night:
> Temperature outside = 69F, Temp in home = 81F,
> Air conditioner trigger set to 75F
>
> method A. With windows being open - My way
> method B. With windows being closed - Wife's way
>
> Question: which one make house temp drop faster and which one costs
> less electricity?

If there is no wind (or no fan blowing the cool air into your house), then
neither method A nor method B will cool the house down more quickly. This
is because the air return to the AC system is inside the house. The hot air
will not get 'blown out' of the house. And there will be minimal air
exchange through the windows.

As the wind increases, eventually method A will cool the house down more
quickly. However, it will take a good sized wind or big windows to beat the
AC. AC units typically cool the air about 20 degrees F. So the air coming
out of the AC will be at 61 F (starting with 81 F), regardless of where the
thermostat is set.

(Let your wife win on this one.)

If you want to save electricity, buy a window fan.

> 2. Use AC for car in a hot summer day
> Temperature outside = 80F,
> Temp of a car parked in sun for one hour = very hot, don't know
> exact temp
>
> After getting into the car
> Method A: open windows, drive for a moment then close the windows
> and start AC. - mine
> Method B: Start AC right away without opening windows. - wife's
>
> Question: which one make car temp drop faster and which one costs
> less electricity?

Method A here will cool the air inside the car faster. But the main source
of heat in the car is not the air, but the roof, seats, floor, windows and
dashboard. They've all been heated to uncomfortable levels, and the heat
capacity of the air is minimal, compared to the rest.

Once the air has been blown out (which will take about 2 seconds), you can
safely close the windows.

There is no electricity in a car AC system (except in an electric car)...
the AC compressor runs off of an engine belt. 

--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}

Relevant Pages

  • Re: BG measurements
    ... bedroom but I only close them during the heat of the afternoon on ... And in the real world us plebs cover the windows to keep out the ... My house is insulated, ... You should see the air that sucker can move in a house that isn't well ...
    (alt.support.diabetes)
  • Speaking of nearly perfect moments
    ... It's raining like hell. ... car with the windows up listening to the stereo. ... I roll down the window a bit to allow some fresh air in. ...
    (rec.music.gdead)
  • Re: Emmergency braodcast network or how to build a net during the apcopalypse
    ... It might be 5 years or more before you can eat food grown out of doors, and not worry about filtering the air. ... Now people will be advised to stay in doors and tape plastic on their doors and windows. ... So if you want to be a hub, and you want to broadcast the apocalypse, what you need to do is to get a hold of a Brinks Truck, or any similar armored car. ... If the threat is chlorine gas, well, even chlorine gas masks, only last 3 to 6 hours. ...
    (sci.physics)
  • Re: 2000 Echo "bass-ackward" defroster
    ... The buttons in my car have symbols on ... The windows cleared right up. ... moist air that condensed on the windshield. ...
    (alt.autos.toyota)
  • Re: Extravagance
    ... Last winter we were running about 6-7 gallons a day out of 5 humidifiers to keep the air in the reasonably-non-desert range. ... Well, the new part, built by the Best Carpenter ... person's weatherstripping around the windows: ... air needs to come in the house somewhere else. ...
    (soc.singles.moderated)