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[kitti in texas]

We just bought a 1985 13' Skamp with an ac installed in the closet. It blows cold for a few minutes and then starts blowing just air. The previous owner said he put a fan on the outside of the trailer by the vent behind the ac to help. We want to fix the ac right. What do we need to do????

[dylanear]

Probably not getting enough fresh air to the unit. I'd have to see how it's vented to offer any real advice. Does much hot air come out of where ever the rear of the AC unit is vented?

[kitti in texas]

I'm not sure but I'll check tomorrow. We're planning on pulling the ac out and taking a look to see how they installed it. Thanks for your reply and hopefully I'll have better questions after tomorrow.

[dylanear]

Post pics if you can. I'm hoping to finish up my AC install very soon, but may not get all th e venting worked out before I have to head towards California.

[honda03842]

Kitti,
When you installing an air conditioner in a closet, the front of the air conditioner functions just like it does in a window installation. The back of the air conditioner needs to have structure that lets it function like it was outside.

Their are two air flow paths in an air conditioner, a cooling air flow and exhaust air flow.

Cooling air Flow.
Normally air enters thru the front of the air conditioner on the room side goes thru the cooling coils and flows back into the room thru the top front of the AC unit.

This portion of the Air Conditioner is the part that is normally in the room.

Exhaust air flow.
The exhaust air normally comes from the outside the trailer and enters thru the side vents of the air conditioner and exhausts thru the back of the air conditioner.

In a closet installation it is necessary to have a cool source of air for the air conditioner's side vents. The side vent's air must be isolated from the trailer's cool air and the exhaust air.

Isolating it from the trailer's cool air consists of two steps: 1. sealing the front edges of the air conditioner, 2. a cover on the top of the air conditioner. This should prevent the air conditioner's exhaust fan from drawing room air into side vents of the exhaust system.

The next step is to provide cooling air to the side vents. I cut a hole thru the floor of the closet for a cool air supply for the exhaust vents.

It is also necessary to seal the side vents from the exhaust air of the air conditioner. If this is not done the side vents will draw cooling air from the already hot exhaust air.

To prevent the AC from drawing cooling air from the exhaust I place a piece of foam between each of the side walls of the closet (sometimes one is needed on top and bottom depending on the brand of AC) and the exhaust area. All these insulators/isolators are located just after the side vents (some AC units also have top cooling vents as well).

I also have a second hole in the floor for the exhaust air to exit the trailer. In my case I mount two small muffin/computer fans to push the exhaust down and out.

To prevent the hot exhausted air from routing itself to the cooling vents, I put a divider between the exhaust input (cool air) and exhaust output (hot air) under the trailer.

Hope this helps. If you need more information please ask. I think there are some pictures under Modifications/Preparing a 1991 Scamp.

[dylanear]

Yeah, what Norm said.

I'm getting my cool air from the dinette seat behind the closet. Not enough room in the bottom of the closet for vents, and the closet is open to the seat anyway.

[kitti in texas]

Thanks Norm, Ginny, and Dylan. We took the ac out today and put it in a house window to make sure it works right and it really cooled good so we guess it's the ventilation. There is only 2-3" of room on one side of the ac and less than that on the other. We also removed a shelf they had installed above the ac for storage. The back of the ac is about 8" from the opening in the wall to the outside. We're going to try it tomorrow with the opening above it and we hope that helps. Thanks again for all your advice!

[dylanear]

It will not work properly with the opening above it. The sides and top need a constant supply of fresh outside air, all hot air from the back needs to be vented out of the trailer without it mixing with the fresh air going in the sides and top. The fresh air from outside should not mix with the inside trailer air before going in the top and sides of the AC unit.

[kitti in texas]

Yeah, my husband has decicded to build a "chute" (my description) to go from the back of the ac to the wall where the cut out is. The "chute" will slope down some, allowing room around it. Hope this works. Thanks for the info!

[dylanear]

Yep, if there wasn't one before, that's probably why it didn't work. That incoming air and outgoing hot air should not mix or the unit will not operated efficiently. Sounds like you're working it out.

That venting is the main thing I have left to work out myself.

[kitti in texas]

I hope that fixes it! I can't wait to go camping in it but Texas is too hot right now to go without ac. I'll keep you updated on our progress and good luck with yours!

[Donna D.]

HI Kitti, looks like you're getting plenty of help here on FiberglassRV. I have nothing to offer for your problem, but wanted to take the time to say

[steve dunham]

Originally Posted by honda03842

Kitti,
When you installing an air conditioner in a closet, the front of the air conditioner functions just like it does in a window installation. The back of the air conditioner needs to have structure that lets it function like it was outside.

Their are two air flow paths in an air conditioner, a cooling air flow and exhaust air flow.

Cooling air Flow.
Normally air enters thru the front of the air conditioner on the room side goes thru the cooling coils and flows back into the room thru the top front of the AC unit.

This portion of the Air Conditioner is the part that is normally in the room.

Exhaust air flow.
The exhaust air normally comes from the outside the trailer and enters thru the side vents of the air conditioner and exhausts thru the back of the air conditioner.

In a closet installation it is necessary to have a cool source of air for the air conditioner's side vents. The side vent's air must be isolated from the trailer's cool air and the exhaust air.

Isolating it from the trailer's cool air consists of two steps: 1. sealing the front edges of the air conditioner, 2. a cover on the top of the air conditioner. This should prevent the air conditioner's exhaust fan from drawing room air into side vents of the exhaust system.

The next step is to provide cooling air to the side vents. I cut a hole thru the floor of the closet for a cool air supply for the exhaust vents.

It is also necessary to seal the side vents from the exhaust air of the air conditioner. If this is not done the side vents will draw cooling air from the already hot exhaust air.

To prevent the AC from drawing cooling air from the exhaust I place a piece of foam between each of the side walls of the closet (sometimes one is needed on top and bottom depending on the brand of AC) and the exhaust area. All these insulators/isolators are located just after the side vents (some AC units also have top cooling vents as well).

I also have a second hole in the floor for the exhaust air to exit the trailer. In my case I mount two small muffin/computer fans to push the exhaust down and out.

To prevent the hot exhausted air from routing itself to the cooling vents, I put a divider between the exhaust input (cool air) and exhaust output (hot air) under the trailer.

Hope this helps. If you need more information please ask. I think there are some pictures under Modifications/Preparing a 1991 Scamp.

Norm : Wouldn't a thru the wall AC which does not have side vents for exhaust air intakes work better than a window AC . I have one in a 14 " outside wall it blows cool air out the front ,hot air out the back and has no side vent openings. You can buy a screen for the outside to protect the coils And you would not need exhaust fans to get rid of the heat

[kitti in texas]

Thanks for the welcome Donna D and all the input from everyone. Appreciate it!

[honda03842]

Norm : Wouldn't a thru the wall AC which does not have side vents for exhaust air intakes work better than a window AC . I have one in a 14 " outside wall it blows cool air out the front ,hot air out the back and has no side vent openings. You can buy a screen for the outside to protect the coils And you would not need exhaust fans to get rid of the heat

Steve,
I didn't know that thru the wall AC units were different than window AC units. It seems to me that a thru the wall AC unit has to source the exhaust air from somewhere and certainly not the room air.

A thru the wall AC unit must have inputexhaust air either on the side, top bottom or rear.

I believe it's the same issue, the input air to the exhaust coils must be cooler cooler than the exhaust air. It must be sourced from somewhere and isolated from room air.

[kitti in texas]

Okay, my husband is going to build a completely enclosed duct (chute) from the back of the ac all the way to the approx. 15" square cut on outer wall. Then he is going to cut an approx. 5" circle above the existing 15" square cut for the side vents of the ac to get fresh air from outside the trailer. Does this sound like it will take care of the problem we have with the ac not cooling? Advice please????? I hate to cut another hole if this won't work!

[jimcapon]

I recently put an A/C unit in my 66 Aloha canned ham trailer. I got the info from a fellow who rebuilds these small campers and posts the progress on Youtube. The solution to exhaust the hot air was to put a small fan facing the exterior vent opening. It's a great looking install and it worked on my unit. Send me a PM & Ill eMail a pic. Can't seem to get it to post on this link. I don't see why it wouldn't work as well on your unit.

[dylanear]

Originally Posted by kitti in texas

Okay, my husband is going to build a completely enclosed duct (chute) from the back of the ac all the way to the approx. 15" square cut on outer wall. Then he is going to cut an approx. 5" circle above the existing 15" square cut for the side vents of the ac to get fresh air from outside the trailer. Does this sound like it will take care of the problem we have with the ac not cooling? Advice please????? I hate to cut another hole if this won't work!

I think that will work, but heat rises, so you may end up pulling heated air back into the intake where you want cooler air to come in, not warmer air. Best to get the cool air, from below or far away from the hot air vent. A little will probably make no noticeable difference, but if a sizable percentage of the hot air gets pulled back in, efficiency and cooling effectiveness will be affected to some degree.

[glamourpets]

If this doesn't work, the only other consideration would be to improve airflow with fans.

Climate and the size (BTUs) of the air conditioner have got to be a factor here too. In a climate that is "a little bit hot" you are only going to need "a little bit of cooling power."

[kitti in texas]

Thanks y'all. And my husband said he is going to get a small fan and install it above the ac in the closet to blow down on the ac. It does get very hot in Texas and we haven't got to use our Skamp yet because of this problem. My fingers are crossed!!!