A/C not up to par for 31sqb Cougar

[Bob Landry]

The 20 degree split is only applicable if the unit is large enough to cool the space. If it's undersized, you will never see the split, even if it is correctly charged. An amp measurment on the compressor will tell if it's charged correctly. If it is, and you don't get the split, then it's undersized. The good thing about the amp check is that it's valid even if you are leaking air due to a duct problem.

[Jay Pat]

On my trailer, I found inside the unit where the partition between the "cold air" and the "return air" was short and was allowing air escape over. I found this when checking the filter. Was able to fix with cardboard filler on the bottom of the partition.

Is your outside door used often? Kids coming and going?

I made outside covers for the windows and frames with Reflectix and is held in place with Industrial Velcro. The frames bring in heat, too! This is used when parked.
Hope this is helpful!!
Pat

[bgilly]

Originally Posted by Bob Landry

The 20 degree split is only applicable if the unit is large enough to cool the space. If it's undersized, you will never see the split, even if it is correctly charged. An amp measurment on the compressor will tell if it's charged correctly. If it is, and you don't get the split, then it's undersized. The good thing about the amp check is that it's valid even if you are leaking air due to a duct problem.

Bob, this is not entirely true. You can get a 20 degree difference if the unit is slightly undersized, it just takes longer.
Amp values are not accurate either since voltage variations directly influence amp draw; the lower the voltage from name plate the higher the amps, the higher the voltage - lower amps. Not every power outlet is going to be right at 120 volts ac.
A unit very low on refrigerant will have to work harder and also cause the compressor motor to run hotter therefore pull more amps, so amp information can be helpful for indepth troubleshooting.
Running the camper on longer power cords, poor power outlet connection and other factors result in amp levels.

JetMek, I recall you stating you inspected the duct work but I understood you checked it at the discharge (grill) but I understand that you inspected the duct from end to end. Every camper I've owned with ducted A/C had poor sealing at the A/C unit discharge (plenum). I also had a similar issue that Pat mentions between the return and supply. I fixed mine with weatherstripping.

Bobby

[Bob Landry]

Originally Posted by bgilly

Amp values are not accurate either since voltage variations directly influence amp draw; the lower the voltage from name plate the higher the amps, the higher the voltage - lower amps. Not every power outlet is going to be right at 120 volts ac.
A unit very low on refrigerant will have to work harder and also cause the compressor motor to run hotter therefore pull more amps, so amp information can be helpful for indepth troubleshooting.
Bobby

The amp draw check is relative to outside ambient temperature, not line voltage. The compressor amp draw shown on the name plate is at 95 degrees. The change in amp draw is 1 amp for every 10 degrees shift in temperature, plus or minus. A compressor that is stated to draw 12A @ 95 degrees will draw 12.5A @ 100 degrees, 13A @ 105 degrees, etc. This is for a correctly charged unit. I don't know if this would also apply to residential or comercial units, I havn't asked, but this comes from Dometic, not me, and it is how they will tell you to check one of their units for proper charge without having to tap into the system with a piercing valve. If the unit is low on charge, it will draw less than the stated amerage, so an undercharged unit actually works less because of the reduced charge. I was skeptical when I was first told about this, but I've checked it against a couple of units and it does work. I serviced one last Saturday that wasn't cooling and it was drawing around 6.5A. I sweated in a shraeder valve, evaciated it and weighed in a charge and checked it again, and the amp draw was within .1A of where it was supposed to be.

[Hansel]

Originally Posted by Jay Pat

On my trailer, I found inside the unit where the partition between the "cold air" and the "return air" was short and was allowing air escape over. I found this when checking the filter. Was able to fix with cardboard filler on the bottom of the partition.

Is your outside door used often? Kids coming and going?

I made outside covers for the windows and frames with Reflectix and is held in place with Industrial Velcro. The frames bring in heat, too! This is used when parked.
Hope this is helpful!!
Pat

This was my fix also, I thought I had a a/c unit gone bad but the camper place said the return for the a/c unit need some tape work and believe it or not it worked. A/C is kicking butt again

[BldrRob]

We have the same 31sqb with 30amp service and only 1 ac unit. We live in Austin and get out at least once a month. We bought it in March 2011. I would say that, yes, ours has been able to keep up with hot temps but I'm not 100% happy. I think it should have 2 units. We have tripped the breaker several times when nothing else is being used. IMO this rig should have 50 amp service and be set up with dual a/c.
Hope it works out for you. Keep us in the loop.

[happytrails]

I have owned a 31SQB since August of 2011. I wouldn't say that the AC is not working properly, but I would say that it may be undersized for this length of trailer. On really hot days 90+, it does just an okay job of cooling. I think it usually comes in around 78 or 79. It definitely doesn't hit any type of 20 degree difference except at night maybe. Mostly I have been attributing this to my kids going in and out and in and out and you get the point.

However, I have seen a lot of great ideas mentioned about blocking off heat ducts, chekcing the AC ducts, and a few others so I will definitely be looking at some improvement techniques. I had a similar size AC unit in my dinky little popup and we froze to death in there. I have put a vent pillow in my back vent in the bunk area to help out, but I don't know how much it really does. I would have preferred a larger unit or dual units as others have mentioned, but I can't see spending the money on that now. We bought the RV for the comfort for when we are actually in it, but when we go camping, pardon me, RVing, we are outside 90-95% of the time we are not sleeping and at night it cools off very well.

I hope that the OP gets the issue(s) resolved. I do like my Keystone RV. For the price it's been wonderful so far. We have been "camping" about 15 times since owning it and have 5 or so more trips planned this year.

Edit***
Well I took apart some of the AC duct work and the main cover to the unit inside. I found that the duct work really appears to be cardboard duct which is interesting I guess. All the connections and the volume of air seems to be very good. When I opened up the cover to the main unit I could see that the tape job there was just horrible. I will be removing the factory tape and going to Lowes for more tape if I can't find mine in the basement. Just a poor job on that, how disappointing. Anyway, I have no real way to take the entire ceiling down so I will just have to be okay with hoping that the rest of the cardboard duct work is taped or sealed well. I can't imagine what a chore it would be to take all that stuff off.

Edit #2***
Here is what I found. The first three show bad tape job in main unit. The last picture is just of up inside a ceiling vent showing the cardboard-like duct work. I'm not exactly sure what it's made of but felt like the inside of a shoe box.

[Hansel]

I just don't understand why the A/C is so poorly installed I just returned from a week of camping which went way too quick and was cleaning up the camper when I decided too remove the grill covering the A/C unit, and WOW what a poor job of appling A/C tape, I would think that they would have some type of duct working like your home A/C not this exposed spaces and frame work. I think Keystone needs to look at how A/C unit's are plumbed into the roof and fit a poor installation practice.

[springfield5]

Maybe we got one of the good ones? We spent half of last week camping in 97 to 101 degrees. The inside felt more than comfortable and chilly at night. I just ordered an indoor / outdoor thermometer so I will be able to tell you the actual temps soon...not just my feelings. I did however re-tape the inlet duct before we left thanks to all of the previous input. I also removed the outside cover (on the roof) and taped the return duct. There are many places that air can escape creating inefficiencies. Most can be easily remedied with some foil tape...however I would agree that we should not have too after paying so much money for a quality trailer! Good luck with your A/C and I hope they get everything handled for you.