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Air Conditioning Question

PostPosted: Fri Apr 23, 2010 6:45 pm
by SmilinJack
I tried a 5,000 BTU air conditioner in my 7 X 16 conversion. Outside air temp was approximately 80F. After 2 hours the inside temp was still 78F. The a/c unit is brand new and was putting out cold air, but obviously not enough to cool the trailer. The roof is insulated. The walls are 3/8 ply but no insulation.

My questions are, for those of you who have installed a window type a/c, what size unit did you use, and what is the size of your trailer?

Thanks in advance...

PostPosted: Fri Apr 23, 2010 6:48 pm
by bobhenry
Did ya have it on fan :roll:

Sorry I had to ask !

Seriously I had a situation where the A/C could not keep up with the solar gain but it was 92 and full sun with a see thru (think greenhouse) roof. I don't see any reason why a 5000 btu unit would not cool the trailer unless it just wasn't cooling properly.

By the way I HAVE had mine on fan waiting for it to cool so IT DOES HAPPEN. :oops:

PostPosted: Fri Apr 23, 2010 6:50 pm
by SmilinJack
Nope, High Cool and the coldest setting...

PostPosted: Fri Apr 23, 2010 8:05 pm
by 8ball_99
I believe it.. I put a 5000BTU in my equipment room for my Saltwater tanks.. Long story but point is the room is only 6'6" wide 8' tall and 12' long.. If the room ever got hot before I turned the AC on. Upper 80s the AC would not cool the room.. If I turned it on early it would keep the rook ok but would get warmer and warmer over the day.. I ended up putting a 8000BTU AC in and I'm able to keep the room whatever temp I want. FYI.. A 8000BTU was the exact same size as the 5k and fit in the same hole with out any adjusting..
BTW the ACs were frigidaire brand both the 5k and 8k were the same size..

PostPosted: Fri Apr 23, 2010 9:48 pm
by WesGrimes
This is very interesting. I was planning on getting a 5000btu unit, and assumed it would cause ice to form inside while it was 100 outside.

Anyone else have a report card for how their 5000btu window units perform?

PostPosted: Fri Apr 23, 2010 10:28 pm
by 8ball_99
Well my thought is the smallest roof top ACs I've seen is 10k.. Even though they make trailers pretty small they still only seem to make 10k and 15k units.. I think the 5k units work fine,, They just can only do so much. Non insulated trailer is a pretty heavy load. Even insulated the space is so small just opening and closing a door pretty much replaces half the air lol. I'd just make sure you get a unit that is the same size as a larger BTU AC or atleast make sure you can swap your out with a larger one if needed. Pretty easy to test.. Install it run it on a hot day opening and closing the door. If it doesn't keep up take it back and get a larger one..

5000 BTU

PostPosted: Sat Apr 24, 2010 12:26 pm
by kstephenson
Hi. Mine is a 6 x 12 with the 5000 btu window unit. After I insulated my ceiling and walls with 3/4" insluation. I was able to close the doors and keep cool while still working in my trailer. Outside temps that day in Georgia were around 88 degrees. Have you considered insulation in the walls?

Kevin

PostPosted: Sat Apr 24, 2010 12:58 pm
by Arne
Is it mounted in the wall, or lying on the ground? That would make a difference... some use a manifold and pipe it in, some mount it in the door/wall..

If mounted in the door/wall, I don't understand why it would not cool it.. Also, what color is the roof? White is better than a dark color.

PostPosted: Sat Apr 24, 2010 1:18 pm
by mikeschn
In my first build I didn't allow enough air to come in for the air conditioner. As a result it didn't cool as well. As soon as I took the wooden cover off the back, it worked fine...

Are you choking your a/c?

Mike...

PostPosted: Sat Apr 24, 2010 3:13 pm
by caseydog
WesGrimes wrote:This is very interesting. I was planning on getting a 5000btu unit, and assumed it would cause ice to form inside while it was 100 outside.

Anyone else have a report card for how their 5000btu window units perform?



I have a 5,000 BTU in my 4X8 and it is more than enough, even for Texas.

Spinnernut uses one in his 5X10 TD.

CD

Re: 5000 BTU

PostPosted: Sat Apr 24, 2010 3:36 pm
by len19070
kstephenson wrote:Hi. Mine is a 6 x 12 with the 5000 btu window unit. After I insulated my ceiling and walls with 3/4" insluation. I was able to close the doors and keep cool while still working in my trailer. Outside temps that day in Georgia were around 88 degrees. Have you considered insulation in the walls?

Kevin


I think Kevin has the answer...Is your Trailer insulated properly?

If it isn't insulated properly, its not the Air Conditioners fault.

With no insulation the metal trailer is a conductor and its a crap shoot as to what size you will need.

Image

Hoooogan! 30 day in the Coooler.

Comes to mind.

Happy Trails

Len

PostPosted: Sat Apr 24, 2010 4:14 pm
by SmilinJack
Like I said, the walls aren't insulated. The roof is insulated and is just the bare aluminum color. I plan to apply Coolseal, but haven't done that yet. I don't want to insulate the walls at this point. The trailer is "campable"now and it's camping season. Ripping out the walls is not an option at least for this year.

I think I'll replace the unit like 8ball_99 suggested. I'll take it back to the box store and try a 10,000 BTU unit.

Thanks for all the input guys...

PostPosted: Sat Apr 24, 2010 4:28 pm
by WesGrimes
I have to ask the obvious question. You do have the outside half of the AC sticking through a window or the sidewall correct?

PostPosted: Sat Apr 24, 2010 4:42 pm
by Shadow Catcher
You have approximately 700 cubic feet of space (you did not give height I used 6' high) and if it were insulated you would need approximately 2,680 BTU. You also did not give the exterior color and if it is other than white or silver that will affect thermal absorption.
We used an AC unit this size to cool a bedroom that is better than five times this volume, with no problems, but it is very well insulated with 4"of foam.

PostPosted: Sat Apr 24, 2010 4:50 pm
by SmilinJack
The outside of the trailer is white.

The A/C is sticking through a rear wall which is made of 3/4 inch plywood.