NF....Window A/C units

[crappieperchhunter]

Broke down and put a 12000 BTU window A/C in at the cottage. The only suitable window was in a small bedroom. I have a large fan out in the hall to blow the cold air out into the front part of the cottage where it gets the hottest because of floor to ceiling windows. It is doing the job but the bedroom in getting real cold..otherwords perfect for sleeping...and the main room although cooling down and much less humid is still not down as far as I would like it.

 

The total area I am working with is 400-410 square feet..so I know I have the right sized A/C...according to what I have researched anyway.

 

The next thing I was going to try was putting vents near the ceiling in the common wall between the 2 rooms and having a fan blow air through these vents. My question is this. Is it better to have the fan blowing the hot air into the cold bedroom or have it blowing the cold air out of the bedroom into the hot room?

 

If anyone can answer this for me or offer any other tips it would be greatly appreciated.

[davey buoy]

Make another window opening if possible.More central.That's what we did in our first house,electric heat,no furnace.Less than a day done,and a extra window to boot..

[Roy]

Ding ding ding! We have a winnah!!!!! A round of applause for Sinclair!

[Ralph Field]

My friend has a cottage that would also require a 12,000 BTU air conditioner . I am trying to get him to buy the type that stands inside the cottage and only requires you to vent it through a screen in a window. I think that they are every bit as good as the old style and are definitely easier to place. They evaporate all the water that is produced and aren't as visible to thieves.

[Gerritt]

My friend has a cottage that would also require a 12,000 BTU air conditioner . I am trying to get him to buy the type that stands inside the cottage and only requires you to vent it through a screen in a window. I think that they are every bit as good as the old style and are definitely easier to place. They evaporate all the water that is produced and aren't as visible to thieves.

 

and twice the price..... not to mention additional installation requirements......

[davey buoy]

My friend has a cottage that would also require a 12,000 BTU air conditioner . I am trying to get him to buy the type that stands inside the cottage and only requires you to vent it through a screen in a window. I think that they are every bit as good as the old style and are definitely easier to place. They evaporate all the water that is produced and aren't as visible to thieves.

 

They are fairly loud,and after about 2 hours in humid conditions the tray fills up and shuts the compressor off but the fan still goes.A friend of mine can't give his away.He paid over$600.00 3 years ago.

Edited July 9, 2012 by davey buoy

[mercman]

They are fairly loud,and after about 2 hours in humid conditions the tray fills up and shuts the compressor off but the fan still goes.A friend of mine can't give his away.He paid over$600.00 3 years ago.

 

 

No to mention the heat that the unit removes from the space is quickly transfered back to the room via the exhaust piping.

[Raf]

the portable we have i'd say is quieter than a window unit.. ours is a dual pipe design one intake and one exhaust. never had an issue with the dehumidifier maybe it exhausts outside??

 

but i will say they are not as efficient as a window unit BTU for BTU. i think mercman may be right about the piping contributing to that as the exhaust does get fairly warm. maybe i should wrap it with something?

Edited July 9, 2012 by Raf

[danc]

Ding ding ding! We have a winnah!!!!! A round of applause for Sinclair!

 

Not so sure about that Roy. Why would you just blow that expensive air conditioned air outside? Somewhere, somehow, that air would have to be replaced. After all, Since the window ac only recirculates the indoor air (yes, many have a very small exhaust air port, not nearly big enough to keep the indoor air pressure equal) you'd be creating a negative pressure in the cottage. So the cottage has no choice but to bring in hot, humid air from wherever it can to replace the air being exhausted. An expensive and inefficient proposition. It's a difficult situation for sure, but I'd work off of the "hot air rises and cool air falls" theory. I'd try the fan on the floor at the bedroom door, blowing into the windowed (warmest) part of the cottage first. The coldest air will be at floor level and would push it into the warmest part of the cottage. The bedroom air would be replaced by the warmest air coming back into the bedroom at the door height. Also, a reversable ceiling fan in the windowed area would help. I'd run it in reverse to suck that cold air upwards and mix it with the hot. Noise would be a concern with both the ac and the fan running, but with 35 years experience in air quality, this is what I'd try first.

[mercman]

ding ding ding !!!! Spot on Dan You are exactly right.

You have to circulate the air within the house by vents either in the ceiling or walls, and small slow rpm fans, just enough to cause an airr flow from room to room.

[crappieperchhunter]

Not so sure about that Roy. Why would you just blow that expensive air conditioned air outside? Somewhere, somehow, that air would have to be replaced. After all, Since the window ac only recirculates the indoor air (yes, many have a very small exhaust air port, not nearly big enough to keep the indoor air pressure equal) you'd be creating a negative pressure in the cottage. So the cottage has no choice but to bring in hot, humid air from wherever it can to replace the air being exhausted. An expensive and inefficient proposition. It's a difficult situation for sure, but I'd work off of the "hot air rises and cool air falls" theory. I'd try the fan on the floor at the bedroom door, blowing into the windowed (warmest) part of the cottage first. The coldest air will be at floor level and would push it into the warmest part of the cottage. The bedroom air would be replaced by the warmest air coming back into the bedroom at the door height. Also, a reversable ceiling fan in the windowed area would help. I'd run it in reverse to suck that cold air upwards and mix it with the hot. Noise would be a concern with both the ac and the fan running, but with 35 years experience in air quality, this is what I'd try first.

 

The main room has a cathedral ceiling with a big fan at the peak of the roof. I was already going to experiment with running it in reverse next weekend to help draw the cold air off the floor. I only installed the A/C yesterday and ran it for 3 hours just to make sure everything was OK. I have not really gave it a good workout yet. The bedroom being so small it was cooled down to 20 after about 2 hours...mean while the main room was still 24-26 My concern is the thermostat on the A/C will shut off the unit before the main room has cooled enough. So I was looking at ways to get the cold air out of the bedroom quicker, which is why I was thinking about wall vents up high to move the hot air in faster or the cold air out faster.

 

Just as a side bar. This has never been an issue before this year. Last fall I had 3 big trees taken down resulting in a lot more sunlight beating down on the cottage roof and the big windows in the afternoon. The tree removal was necessary. Two where dyeing and the third was a leaner that hung over the cottage and always concerned me when it got real windy. But boy has it ever warmed up the cottage. Take it from me...if you have some good shade trees around your home or cottage...don't remove them unless you have to

[Ron]

I took a bathroom exhaust fan (2.0 scones) placed it on the floor and ran flex pipe to ceiling in the shop. worked wonders for moving air. You could also go this route by placing the exhaust fan in front of the A/C and use the duct pipe to push the air into the living room.

[largemouthtrout]

12,000 btu should be more than enough for 400 square feet . We are using a 5,000 btu to cool roughly the same area ... also in a bedroom window ... its doing a good job with a small fan to blow the cold out of the room . We keep the bedroom doors open .

 

My though .. without seeing your place .. cover up all those ceiling to floor windows with some nice WHITE curtians or blinds to keep the sun out durring the day .

 

2 hours to cool a room ? thats crazy , something doesn't sound right there .

[crappieperchhunter]

 

 

2 hours to cool a room ? thats crazy , something doesn't sound right there .

 

The room started at 28 and was cooled down to 20 by the time I checked it 2 hours later...not really sure how long it actually took. My point was the main cottage was still much warmer and I wanted solutions to address that issue.

 

I'm thankful for any helpful suggestions I can get whether they are from A/C professionals or from some homegrown McGyver experiments