saving money by..... Running Air Conditioning with windows open at night
theory...@gmail.com
with their windows open to save money, it surprises them.
It's really logical, if you fall into a certain criteria.
1. If the outside temperature is warmer then the inside temperature,
then you need to run the A/C with the windows closed.
2. If the outside temperature is cooler then your inside temperature,
you need to run the A/C with your windows open. (It would actually be
better by leaving the windows open and running a window fan.)
Let me explain with an example....
I live in an area where the daytime temperature reaches 100 degrees.
However, at around 8pm the outside temperature drops down to the upper
70's. The temperature in my house will stay around 90 degrees if I
don't turn on the A/C.
So every day when I get home around 6pm, I run the A/C with the
windows closed. (During this time the outside temperature is still in
the 90's.) However, at 8pm, I open all the windows and turn on the
windows fans to blow in the cool air from the outside (since the
outside temperature has lowered to the upper 70's) and I still keep
the A/C running. At 10pm, I can actually shut off the A/C, however I
keep the window fans running. At 3am in the morning, it has cooled
down the house enough where I actually shut off the window fans also.
However, if I kept all the windows closed, then I would actually have
to run the A/C the whole night.
The concept is similar to when you first go inside a car and the
temperature in the car is way hotter then the temperature outside.
For me if I go inside my car when the outside temperature is 100
degree, the temperature in my car is around 115 degree. Then for the
first minute I open all the windows to allow the 100 degree outside
temperature to cool off the 115 degree inside temperature. After 1
minute, I will close the windows.
Of coarse the best way is having a "total house fan". If I had that,
then I can shut off my A/C at 8pm and just run that.
James
>
> - Show quoted text -
Well YMMV.
In sticky Toronto, you may get lower temps at night, but the humidity
remains high and that is what makes sleeping uncomfortable. Opening
the windows would tend to make the unit work harder to remove
humidity.
We turn the temp on the A/C up high -to about 78 or 80, and so it
doesn't cool much but still takes the humidity out.
Of course in dry places like the southwest US, you could do what you
suggest.
It felt cooler in LA at 100 degrees last week (about 60% humidity)
than it does in Toronto at 90 degrees and 90% humidity. In the desert
it was 110, but less than 1% humidity and it felt great.
James
Beachcomber
>Of coarse the best way is having a "total house fan". If I had that,
>then I can shut off my A/C at 8pm and just run that.
>
house fan', especially if you open up just a few other windows on
ground level and your fan is in an upstairs room somewhere.
Think of your house as a built up resevoir of heat during the day.
You've got to get that heat out, when it is cooler outside. Getting
the hot air out is easy. If you have large amounts of thermal mass
like concrete, brick or stone, it's going to take a lot longer for the
air to feel cooler.
The cheapest way is to move it out is with a fan.
Moving it with an air conditioner might possibly be faster, but then
you have the added expense of a compressor running, in addition to a
fan/blower. The added expenses? More electricity, more complexity,
more wear and tear on you A/C system.
Beachcomber
Ward Abbott
>SMART!
Didya have to requote all that drivel just to add one word?