/diy/ - Do It Yourself

>>1181028
What you want is a a whole house fan, those ac units don't add positive pressure, they don't even bring air in from outside, it just cooling your ambient air and spitting it back out.

>>1181028
see:
>>1181031

These AC units just recirculate the air already in the room. what you are trying to do is completely unnecessary.

>>1181033
>These AC units just recirculate the air already in the room. what you are trying to do is completely unnecessary.

Wait, really? How come I can feel air blowing out the back? Any diagrams to illustrate how these work?

>>1181037

pixies go in one end and cold pixies come out the other end

>>1181037
There's a partition between the inside and outside. They're connected only by some tubing and wires.
The inside "radiator" gets cold from an expanding gas (refrigerant).
The refrigerant is pumped to the outside system where the gas is compressed, which concentrates the heat(thermal energy) which then flows through an outside "radiator" to dump the heat outside.

There's 2 fan blades(blowers). One for the outside & one for the inside. They both use the same motor. (at least on every one I can remember seeing)

If you wanted to seal it better, you could take the cover off and silicon up any air leaks in the partition. Maybe add thin weather stripping around the partition where it seals against the cover.
If there's a vent lever, keep it shut. You could silicone or tape the actual vent cover shut if it doesn't seal well.

>>1181037
There are two airflow systems. There is "inside" system and an "outside" system which are completely separated from each other, and there is no exchange of air from inside to outside. The transfer of heat from inside to outside is through the coolant which travels between the inside (cold) coil and the outside (hot) coil. Here's a simplified diagram of how a window AC unit works.

>>1181264
I have the arrows on the coolant lines backwards, but that's the general idea. The only thing that passes between inside and outside is the coolant/refrigerant lines.

What you need is fresh air intake of some sort. Basically a fan that pulls air into the house from outside, with a filter on it. The downside to this is that in the summer it's pulling hot air into your home and in the winter it's pulling cold air into your home, which lowers the efficiency of your heating/cooling system(s).

The best way to do this while minimizing heating/cooling losses is to do it through an energy recovery ventilator (like in the attached picture)

all the AC units i've worked with, about 5 of them, have either a lever that opens a small opening to allow outside ait to be sucked in, or a small cover plate (2in x 2in typical) that you can optionally remove to accomplish the same thing as the lever.

Sort of gonna Hijack this thread since it is related to my question.

New home owner here. Closing in two days. First time home owner as well. Just some background. Did general contracting for a few years intbetween jobs, very handy.

Anyways, the house I'm buying is pretty small. 650 sq ft small. (Just me, the dog, and the girlfriend. Don't need much.) One of the draw backs is the house only has heat. SE Wisconsin, so it doesn't get retarded hot, but hot enough that I wouldn't mind AC at times. The previous owner went all out with insulation and heating. Baseboard heaters, pellet stove, and gas wall mounted furnace.

Was wondering if there is a smaller AC solution I could install in the attic or crawlspace. Rather not pay thousands for a real deal unit for 650sqft, and don't want the ugly/obnoxious eye sore of a free standing or window unit.

Climateright.com seems to have a decent solution, but they're really only rated for 200-350 sq ft. I could double up, but would prefer a single unit. Heating would be a bonus so I could eliminate the other heaters. I have seen small furnaces for this kind of application, but not any A/C solutions.

Thoughts/Ideas?

>>1181490
Probably just need a ductless system.

>>1181028
Look for in window evap coolers. They pull outside air in through wet membranes and shove that air into your room. If you don't want the cooling or extra humidity, then just drop appropriately sized air filters in instead of the fluid membrane and don't hook the water up. They usually have a house fan setting. You'll need to change the filter pretty often though.

>>1181496
Probably just gonna have to deal with an eye sore of some kind, huh?

>>1181497
probably. you're asking for a central ac without having to do the hard part.
just do it and suck up the cost. do everything but line connections and save some money.

>>1181500
Sounds good. Time to start saving

>>1181050
>>1181264
>>1181271
>>1181328
Thanks, familia.
Any cheap way I can increase air pressure inside anyway?

>>1181681
>increase air pressure inside anyway?

Where is the air to increase the pressure going to come from?

>>1181681
Yeah. A big ass window fan.

>>1181760
He could try a ducted fan. But the problem is the outside warm air is coming inside. He could try to pump air from one room to another but it would cause a negative pressure in that room and when the door opened (assuming it was reasonably sealed to the jam and floor) it would depressurize.

>>1181028
>What materials would be appropriate to add
Activated carbon. You can buy it from pet shops, it's used as a filtration material in fish aquariums. I'm thinking of building myself a room air filter like pic related, which brings me to my own question:

has anyone compared how these work compared to passive (fan-less) carbon air filters (like some carbon in a porous bag hanging somewhere)? I imagine they clean the air faster, but how much faster? I'm not entirely sure if it's worth the extra cost.

>>1181775
>but how much faster
Any filtration system that is moving air actively is going to filter air WAY faster than any passive system will. If there's nothing forcing air the move through the carbon filter media, not a lot of air is going to get filtered because any moving air is going to take the path of least resistance and go around the filter rather than through it.