A/C - unit to use night temps to cool

[newbury]

Don't know how to phrase it exactly and don't know if this is the right forum -
But I'd like to maximize the low temps we get outside over night (right now 55 degrees) to cool when it gets up to the afternoon, mid 80's.
Sort of like opening all the windows, but automated.
I'd like to bring in cold air and chill the house down.
Opening all the windows is a pain and the outside air is humid and pollen laden.

We try to keep the house at a 75 degree max.
As it is due to heat left over from the previous day and heat generated inside the house has only cooled down to 73.

I'm thinking of some type of unit installed in the top floor that brings air in, DRYS it, FILTERS it (allergies etc) and then thru open doors flows down to the basement where in a basement window there is an exhaust fan sucking out warm air.

Meanwhile the regular a/c system is running in "low fan" mode to help circulation between all the rest of the house.

We could stand the house cooling down to 60 degrees even.

Critical things are drying and filtering of the air.

Has anyone seen something like this for sale? It seems two simple window units would do. One similar to an a/c but only for drying and filtering, one to pump air out.

Has anyone built something similar?

 

[brin]

We are here in Georgia and we do what you are talking about and our house stays cool all day ..As long as it is cool in the Morning...50 deg here this AM ...we turn on our whole house fan and open the door to our screened porch and pull in all the outside air...usually takes about an hour...then we close the door and turn off the fan.

The house stays cool all day except on days when the outside temp goes to 90 deg or more and then we need the AC for only for a short time.

This might work for you if you could figure a way to filter the air coming in...such as use a whole house attic fan to bring the air in ..but only open a window and buy an air purification filter, used for furnaces and attach it over the window opening....That might work for you.

 

[sandman2234]

Wondering if a "whole house attic fan" pulling air thru filters and using a dehumidifier to keep the humidity down would do the job. I installed a thermostatically controlled fan in the attic of a shop a few years ago, worked ok, but placement of the thermostat seemed to be critical as originally I installed the thermostat next to the fan, and it ran almost all the time. When I moved it to a better location (ceiling height, near air intake) it did better. We weren't worried about humidity or filtering, but seems like those could be easily addressed.
David from jax

Brin types faster than I do, apparently!!

 

[MarkV]

The Attic Fan's mentioned were used for just what you describe before A/C. Very common here in the south. You could build a frame that held an A/C filter and fit in one or two windows for an intake.

If you build your own system have your intake down stairs and exhaust in the attic. It will be much more effective. I will say that you have just moved to Mississippi and I think you will find that shortly you will be back to the A/C to fight humidity though.

MarkV

 

[radioman]

Why not take advantage of heat rises? If you have a basement, having a fan in basement window or door with allergen filter in front of it blowing cool air in basement, Just keep door open leading to basement in house and have a one,two windows farthest away from top floor stairway open at top floor of your house. The fan in basement can be on a timer, but you will need to "open/close" windows on top floor during fan operation on/off. FYI, I dont think a simple window fan will work. You might have to look into a squirrel cage made for furances.

 

[newbury]

I'v tried the whole house fan with a screened porch. Works well except for humidity, pollen, and having to close and open doors.
I'm not set on exhaust thru basement. It's just that cold air sinks and what's happened in the past is a virtual thermocline coming up out of the basement.

I'm hoping to run across something that could use a material like silica gel for a desiccant during the night and have that regenerated in the heat of the sun during the day. Coupled with a filtering system.

Just reading I found out that there are brands of cat litter that are silica gel.

 

[Groo]

AC systems are just heat pumps. insulate the house well and crank the AC when the outside is cooler than the inside and you will get more heat transferred per KWh.

The really old fashioned way was big thick stone walls. all that stone would level out the temperatures. they'd give off the heat of the day during the cold of the night and absorb the heat from inside the house during the day.

sounds like what you really want is a geo-thermal heat pump, but that isn't cheap.

 

[dodge man]

I agree, it sounds like you really wan't geothermal.

 

[vwnotrunning]

Depending on your A/C system - there are "economizers" available that will allow the unit to suck air in from the outside based on the temperature and humidity of the outside air. When conditions are right it will utilize the cool air outside in lieu of operating a compressor. This option makes all air still goes through your filter (based on type of filter) to remove impurities. Not always cheap to retrofit - but this would be the most automated option.