A/C not up to par for 31sqb Cougar

[JetMek]

I've had miserable experiences with my 2011 Cougar 31sqb due to the lack of cooling from our a/c unit. The dealer replaced it last year and it still can't keep the trailer cool, the dealer pretty much gave up. I'm wondering if anbody else has this problem..? I live in south west Michigan so the humidity levels get up there but all the campers around us don't have the same problem.

[SAD]

Define what you mean by not up to par. What's outside air temperature. What interior temp does it maintain?

[byrdr1]

dual AC..
15k ducted in living area,13.5k straight blow in 5er bedroom.
last year we were able to keep the whole camper in the lower 70's in full sun at Myrtle Beach, SC.
slept under a blanket in the bedroom the first night or two until I figured out the tempature range of the bedroom unit.
randy

[KanTC]

JetMek,

Given the fact that it's a 36 ft long trailer, with a single A/C unit, it wouldn't be unusual for the A/C to be
'sub-par' in hot/humid weather. If you have 50 amp service, a 2nd A/C unit would be the best remedy.

One other thing to consider... did the dealer check the ducts/ductwork to ensure that the cool air
isn't escaping into the area above the ceiling?

Sorry about your A/C issues, but welcome to the forum.

Terri, the co-pilot

[JetMek]

This is a 30 amp service camper with one A/C unit. I'm not sure if the dealer checked all the duct work but I'll be sure to have them do it because it's going back to them. There is all types of campers around us with 30 amp service and same BTU ratings that do not have this problem so to me it's unacceptable. We love the camper itself but are struggling to recommend it to anyone due the A/C issue.

[JetMek]

It will not keep the 20 degree drop in temperature from outside temp to inside temp as published. It was 90 degrees outside and I couldn't get the inside temp below 80-82 while my neighbor campers were in their cozy 70-72 campers. I need to know if this is a 31sqb issue or a Keystone wide issue..?

[Terrydactile]

As mentioned before, I found all of my duct work in terrible condition right from the factory. I pulled all of the registers and taped up the joints. I could not believe how sloppy the workmanship was. There were holes big enough for my to stick five fingers through. Also the ends of the ducts were tapped with some kind of cheap tape that had come loose. I fixed those by fitting a piece of foam pipe insulation up through the last register in the run and wedged it into place. It made a tremendous amount of difference. I would estimate that 1/3 to 1/2 of my cool air was going into the space between the ceiling and roof.

Hope you get this fixed.

[JetMek]

Thanks for the heads up on the duct work, I'll definetly look into that immediately.

[JetMek]

Inspected the duct work last night with a video borescope and found no damage (which is good I guess). Now back to square one...

[Roberson4]

Our 2011 340TG ducted AC hardly blows any air out of the forward AC vents. I have not checked the AC duct work yet. The rear (4 of them) AC vent have good air flow. The rear bathroom get so much air I actually bought a register that has flow restricting (adjustable) flaps in them.

I am also thinking I need to block the heater registers completely somehow. Our 5ver has heater duct in the storage compartments and to the black/gray water tanks. My thinking on ours is: Heat may be raising thru open heat ducts from 'outside' and or cold air may/could be escaping out thru the heat ducts in the floor.

I know this thought has nothing to do with the very low flow coming from the forward AC vents, but could affect cooling.

[JetMek]

I'm at a loss for ideas, I believe the camper needs a larger A/C unit or even a second one but the camper is only equipped with 30amp service. I'm curious to know if any other 31sqb owners has this problem. Of course Keystone says no but I'm not convinced.

[JRTJH]

JetMek,

When we first got our RV, I took all the A/C registers off the ceiling and found that all but one of them were not sealed to the ceiling. In other words, the cold air was flowing through the ductwork, but at the registers, it was leaking into the ceiling joist area rather than being forced into the camper. When I held my hand to a register, it felt cool, there was some air flow, but after I used aluminum duct tape (not fabric duck tape) to seal all the ductwork to prevent air loss, the velocity of cool air doubled and our RV was much MUCH cooler. Also take the A/C ceiling cover off, look carefully at the area around where the forward and rear ducting is connected. I found that we had almost an inch of open space where air was being blown into the ceiling, not into the ductwork. Once those leakage issues were resolved, our A/C was much more able to cool our RV, even in 100+ weather last July when visiting North Carolina. I won't say it was "frigid" inside, but we were comfortable, even with the sun beating through the big back window.

John

[f6bits]

Does your A/C have the “feature” where you slide a lever at the AC main vents and it sends all cold air straight down? It’d be nice to get a feel for how much and how cold the air is coming out of the AC.

[Bob Landry]

Originally Posted by JetMek

It will not keep the 20 degree drop in temperature from outside temp to inside temp as published. It was 90 degrees outside and I couldn't get the inside temp below 80-82 while my neighbor campers were in their cozy 70-72 campers. I need to know if this is a 31sqb issue or a Keystone wide issue..?

Published where? The 20 degree drop that is frequently mentioned is the difference between the discharge air from the AC and the return air being pulled back in it from the inside. It's also known as the split across the coil. It has nothing to do with outside temperature. There is no air conditioner manufacturer that specifies that their unit will maintain an outside/inside temperature differential. if you are told that, it would be coming from a dealer/salesman, and he is mis-informed.

That said, even a 15K BTU unit is undersized for the size trailer you are trying to keep cool. You may be able to help it some by pulling the grill and air registers and making sure that all of the discharged air is being ducted into the trailer and not leaking into the ceiling areas.

[springfield5]

My wife and I bought our Cougar this spring but have not had a chance to use the A/C. Since I only have it hooked up to a 15a circuit I can't run the A/C but can tell you that all of my celing vents have plenty of air flow when the fan is on...much more than I expected suprisingly. Our next trip isn't for a few weeks so I will be able to update on the performance then. Also, we will be spending a little time in the Florida Keys this summer so that should be the ultimate test. Please keep us informed if you find anything wrong but I suspect it just may not be up to the task given that the unit has been replaced with the same results.

A good idea, as previously stated would be to open the "main room vents" located on the bottom side of the A/C unit and check the outlet air with a thermometer and then compare it to the ceiling vents. This may help determine if the A/C unit is sub-par or if it is a ducting problem.

I hope you find the cure and good luck.

[JetMek]

thanks for all the concerns and questions, the dealer is currently getting ahold of Keystone to have them take it and check it themselves since I live close to where they're manufactured. I'll keep you updated.

[bgilly]

I'm not a very active member here (too busy with my real job) but I believe I can lend some assistance in diagnosing A/C problems. I do have HVAC background if that helps add "clout"

Some have already mentioned the 20 degree difference. Here is the scoop on the 20 degree rule. A healthy, properly installed unit will have a 20 degrees split between return temp. and supply temp. This should be measured with the same thermometer. Basically take the reading at the return grill (typically right under the unit) and then take a reading at the closest discharge (preferably not right at the A/C with the quick cool damper). You should measure a 15 - 20 degree split between the two.
Anything less than 15 degree could be a leaking gasket between the discharge baffle (plenum) and the return. This is an easy fix by sealing baffle separating the two sides. You should remove the ceiling trim to do this properly.

If the split is greater than 20 degrees, the first and easiest causes are air leaks. Other causes could be an undersized unit or poor system health such as a dirty coil (inside coil or outside coil), low refrigerant, faulty compressor and other mechanics of the A/C system.
Air leaks can be mostly on the supply air side and as some have already pointed out the ducted system be a weakness. But don't just check at the grill but also at the unit itself. That is where the air pressure is highest. The air leaves the unit into the discharge plenum. The plenum splits into two ducts. On the port side one duct goes to the front of the camper on the starboard the duct goes to the rear (or could be vice-versa). I have found poorly sealed ducts to the A/C plenum causing significant amount of air to dump into the ceiling and never reach the living space. You again would need to remove the ceiling trim to inspect. It there are gaps in either plenum or to the duct you can seal them with foil tape that can be purchased from Home Depot. Contrary to its name, don't use "duct tape", it doesn't work well.

If the duct and plenum look OK, then close off half the grills on each duct run leaving the grills closest to the A/C unit open. Close doors and drapes. See if the temp begins to drop to a comfortable level. If it does, your A/C is just too small for the amount of heat in the camper. Most campers can do fine with a 13,500 BTU A/C unit but if you have a lot of people, cook inside a lot, leave a lot of lights on, have all the shades or curtains open and parked in a very sunny site, you have created a substantial amount of heat load for the 13,500 BTU of air conditioning. A 15K BTU would improve the heat removal ability but my thinking is to look for the heat sources first before upgrading to a higher BTU A/C.
Also, don't expect and A/C unit to cool down a 100 degree plus camper in a mere 30 minutes. Part of the job of the A/C is not only to remove the heat but also the humidity in the air (this is why you see water dripping from air conditioners - they are conditioning the air).

Well, that is my input on the A,B,C's of the air conditioner.
I have a good technical write-up I put together a few years ago on RV air conditioner units. I would be glad to share it here if there is interest in it.

Good luck and remember to use caution.

Bobby

[CincyGus]

As mentioned, I think your asking a lot of a single AC for that size camper. Besides the advice you have already been given on making sure the ducts are taped well and checking temps, I'd ask if your windows are tinted and/or do you leave your shades closed during the day? Also, are you using any insulation in roof vents such as the inflatable pillows you stuff in the 14"x14" crank vents? All of these things can help reduce the amount of sun that is beating in and improve your AC's ability to help cool your unit.

I only have a 23' Passport UL with a 13.5 and it frankly freezes us out and I like it cold. I camped week before last and with the highs in the lower to mid 90's all week, my camper never got above 72 degrees during the day with the thermostat set at 69. I did do the above (shades closed by noon and inflatable pillows in the vents. My girls slept with sweatshirts on and sheets and blankets on their beds.

[JetMek]

Thanks Bobby for the advise, I did inspect all the duct work as you mentioned with a video borescope and found it all to be good. The plenum was not sealed very well so I foil taped that up as well. I'll try taking temp splits the next time we got hot around here in Michigan (up and down weather). I still believe the unit is too small for my camper but the dealer and manufacturer disagree with that and I'm currently working with Keystone on taking it back to the factory to get tested out there since the dealer gave up.

[JetMek]

BTW the dealer agrees with me that the camper isn't cooling like it should but states the a/c unit is good. hmmmm