Home made air conditioner?

lml999

Feeling the Heat
Oct 25, 2013
497
Cape Cod, Massachusetts
Maybe I have too much time on my hands (not really...), but here's a challenge...

We have a good sized room (12x20) that experiences a lot of heat gain during the day. 80 square feet of south facing glass plus two skylights. I'm going to cover the glass with 90% sunblock screen material, which should cut down on some of the solar gain during the summer.

We also have an LCD tv and av receiver that generate some heat. I've thought about relocating the receiver, but that's challenging.

The two windows in the room are too narrow for conventional AC units. We run a large AC at the opposite end of the house, the closest location where I can mount a window unit.

For now, we're making do with the window AC units. At some point we'll invest in mini splits or perhaps a high velocity system...but that's a ways off.

The room has an HRV return feeding fresh air in. Typically that air is just a couple of degrees higher or lower than ambient inside air.

The HRV unit is in the basement, directly below the room in question, with easy access to the ducting.

So I'm thinking (which usually gets me in trouble...)

Can I cool the air being returned by the HRV?

One approach is to insert a cooling box inline that has a small water radiator and use either my well water supply or a ground loop with a solar powered pump to provide the cooling function. I have not done any testing of ground or well water temperature yet. The ground loop would be easier, as I would not have to deal with circulating house water through this setup.

I don't know if this would provide sufficient cooling to be worth it. I've done some googling and found people creating McGyver type cooling systems with copper loops going through buckets of water and ice and then looped on fans. That approach would require constantly adding ice...

I've already got the air flow, so I'm wondering how to condition it...

By the way, the other short term option is to use a portable air conditioner and exhaust it through the window or the fireplace. I haven't heard good things about those units...

Comments appreciated!
 

blades

Minister of Fire
Nov 23, 2008
3,399
WI, Leroy
basically what you are talking about was referred to as a swamp box. warm air through pipes with cold water cascading over pipes. in your case reversing - water in pipes air flowing around which is the same principal as a standard ac coil. old car radiator, pump, fan=basic supplies. Well water will be apx 50::F if you pump it out and back in (geo thermal ) eventually the surrounding earth will warm up and you lose the differential, unless you divert the water somewhere else. It is better to run the warm air in the pipes and mist them with a hi velocity fan and water. The combination of mist , fan & evaporation is more efficient and uses much less water. Biggest hurdle is what to do with the water that does not evaporate. this is a pretty slow air speedin the pipes to accomplish the heat transferance with alum. being the best for heat transfer. Used to have a building on the river using the swamp box to cool it in the summer- water drawn from and returned to river via a pump ( pricey running that pump).
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,721
NE Ohio
What about using one of those portable AC units...I think the exhaust can be adapted to just about any window size...and they have gotten pretty cheap the last few years...not much more than a window unit.
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begreen

Mooderator
Staff member
Nov 18, 2005
81,155
South Puget Sound, WA
What about using one of those portable AC units...I think the exhaust can be adapted to just about any window size...and they have gotten pretty cheap the last few years...not much more than a window unit.
View attachment 227846
Someone showed me a picture of a 5000btu unit the cobbled into their RV recently.
 

lml999

Feeling the Heat
Oct 25, 2013
497
Cape Cod, Massachusetts
Save your money for the mini-splits. Get a nice fan. :)
Sigh...

I have no problem running the AC at the other end of the house and dealing with the imbalance. SWMBO, on the other hand, doesn't like it COLD in that end of the house... So...

If I stall long enough, the issue will go away and we'll pick up the conversation about getting the insert installed in the fireplace. 5 cords of seasoned oak and I have no place to burn it...
 

xman23

Minister of Fire
Oct 7, 2008
2,036
Lackawaxen PA
What about using one of those portable AC units...I think the exhaust can be adapted to just about any window size...and they have gotten pretty cheap the last few years...not much more than a window unit.
View attachment 227846
I have one, which we use in a single bedroom. I don't recall the size, but I think it was fairly large. I works but has a hard time keeping up with the heat of the day. Being the engineer I am, I got thinking about whats wrong. My theory is the condenser is within the unit. That's the part that would normally be outside. So the heat from the condenser is ducted and exhausted out your window. The problem, as I envisioned it, is the air to do this comes from the room your trying to cool. Creating a negative air pressure in the room. The air replacing it is hot air from the surrounding rooms. Based on this and the efficiency of the machine I theorized the room should get hotter. Must be something wrong with the calculations. A bit of rebuilding of the machine, creating a second duct should fix this design flaw. But as usual I have more idea's and plans than time.
 

fbelec

Minister of Fire
Nov 23, 2005
2,667
Massachusetts
swamp coolers don't work if it is humid. if you don't have the money for a ductless split pop a friedrich air conditioner thru a wall. i say friedrich because they are one if not the quietest wall or window units out there. and they last a long time. they are priced between a normal window air of good quality and a ductless split.
 

TillLindemann

New Member
Jan 22, 2020
1
Vienne
Sigh...

I have no problem running the AC at the other end of the house and dealing with the imbalance. SWMBO, on the other hand, doesn't like it COLD in that end of the house... So...

If I stall long enough, the issue will go away and we'll pick up the conversation about getting the insert installed in the fireplace. 5 cords of seasoned oak and I have no place to burn it...
Hey there, so I think that I have problem with my Air conditioner, so when I was on the job, I've comed at home and I felt that smell of aircon that was all over the place. So I've tried to fix it but I actually don't know how it works so I made it worse and it was over for me. Later when I tried to ask on different forums about this I found an article about aircon servicing that helped me to fix it fast and with high quality of their work.