Air conditioner not cooling

[Dixiedog]

We have a 2012 cougar fifth wheel 276lfswe, we live in Southern California where it gets pretty hot. We love the trailer but, the single air conditioner can't cool the trailer when it's over 95 degrees outside. Our model has a lot of windows and the service dept where we bought it suggested we cover the windows on the inside with insulated covers and put sun shade covers over the outside which we did and it has not helped. Anyone have any other ideas?

[Ken / Claudia]

Just general RV a/c advice. It is not a home a/c system. Check your manual and you will find that the a/c will only drop the air temp by 20 degrees. My advice is the same as the manual, if your parked, start the a/c early in the day/morning and keep it on. When traveling in hot temps. we turn on the genny and move as much air thru it as possible while stopped to eat etc. it will not cool off during that time.

[GaryWT]

We are not in the south but at hot times, the first day can be tough but we try to get the temperature down as low as we can over night and then try to maintain it. Sometimes the temps rise some in the afternoon but we catch up at night. If you don't let it get cold at night then it might never get where you want it.

[Bob Landry]

The 20 degree drop in temperature, also referred to as the split across the coil applies to all air conditioning systems, not just RVs.
I'm doubting that a single AC is enough to sufficiently cool that size trailer. The unit can be verified for proper charge using a clamp-on amp meter and if after verifying that, the unit does not give you a difference of 18-20 degrees between discharge and return air, it is most likely undersized. If it is a 15K BTU, the next step would be to add a second AC.
All of that being said, there are countless threads on here about checking to see if your blower plenum and duct work are properly taped/sealed. Air that is being sent into the ceiling is doing you no good at all, so the first step is to fix that. Do not be alarmed, every unit that leaves Keystone suffers from this.

I just completed the installation of snap-on solar screens, but I havn't taken a trip yet to test effectiveness, but that is also an option. Het that doesn't get in does not have to be removed.

http://www.keystoneforums.com/attachments/photobucket/img_132624_0_d42079183b3779f26fb1d335221f7e8b.jpg (http://s102.photobucket.com/user/rlandry6/media/screen1_zpsf8741cf6.jpg.html)

http://www.keystoneforums.com/attachments/photobucket/img_132624_1_047c3f8bc8c35d3d79f4b2b8fd0dffa4.jpg (http://s102.photobucket.com/user/rlandry6/media/screen2_zps7871a2bf.jpg.html)

[glenalt]

[QUOTE=Bob Landry;132624]The 20 degree drop in temperature, also referred to as the split across the coil applies to all air conditioning systems, not just RVs.

I just completed the installation of snap-on solar screens, but I havn't taken a trip yet to test effectiveness, but that is also an option. Het that doesn't get in does not have to be removed.
===

I have just purchased a Cougar and it has the 15,000 Unit but in Fl last week it ran almost full time until the evening or over cast.

I'm curious did you use the stick on snaps and where did you purchase the product? I googled and came with Home Depot but not sure if it's the same stuff.

Any input would be appreciated.

Glen

[2014Fuzion300]

We just spent a week in Fernandina beach Florida and the only thing I can tell you is that without two AC units (15000 + 13500 BTU's) it would be impossible for me to do it again !!! (for our Fuzion 300).

[Bob Landry]

[QUOTE=Bob Landry;132624]The 20 degree drop in temperature, also referred to as the split across the coil applies to all air conditioning systems, not just RVs.

I just completed the installation of snap-on solar screens, but I havn't taken a trip yet to test effectiveness, but that is also an option. Het that doesn't get in does not have to be removed.
===

I have just purchased a Cougar and it has the 15,000 Unit but in Fl last week it ran almost full time until the evening or over cast.

I'm curious did you use the stick on snaps and where did you purchase the product? I googled and came with Home Depot but not sure if it's the same stuff.

Any input would be appreciated.

Glen

I did use the stick on snaps and they came from a company called EZ Snap. They don't use any outside distributors, so I doubt the Home Depot stuff is the same. These use a 3M adhesive and are almost impossible to get off once applied and cured.

The screen material is made by Phifer and is the same screen sold by Home Depot. EZ Snap also sells solar screen but they are twice as much as Phifer. I had both companies send me samples and I couldn't tell a bit of difference between the two products other than price. I went with the 90% heat block. It darkens the inside a little bit, but to be cool I can live with turning on a light to read, and it does give you a little additional privacy. I tested mine in a Central Texas July week and my single air conditioner kept my 35' trailer comfortable during the day and cycled on and off. I'm sold on solar screens.

To the OP.. There have been numerous posts about this ad nauseum. Drop the lower cover of the AC and make sure that the plenum is properly taped to the duct on both sides and that there is no cold air leaking back to the return air side. Pull the ceiling vents and tape up the holes where the duct was cut for the grills. You are leaking air into the ceiling area and it's not doing you any good there. Use aluminum/foil duct tape for this.

[Kristi]

You might also add some vent pillows to help with heat coming in through the vent covers. We are fortunate enough to have the cougar parked at home with a 50 amp plug so I usually turn on the A/C a couple days ahead of time to cool off the inside a bit. The A/C has to work pretty hard when all the furniture & stuff in the trailer is already hot.

[kellydog98]

Here's my 2 cents. I was in the same predicament you were. Couldn't get the rig to cool down enough. We shut curtains and tried running fans. Then it dawned me...If your return air is like mine its on the celing. Here's what was happening. All of those 12v lights you have on is generating so much heat and is being sucked into the cool air return for recycling. After I realized this, I turned off the celing lighs and just like that...the air conditioning became much cooler and we became happier. We lived with the lights on the wall just fine. Hopefulling this will help to cool you off. Good Luck!

[JRTJH]

Here's my 2 cents. I was in the same predicament you were. Couldn't get the rig to cool down enough. We shut curtains and tried running fans. Then it dawned me...If your return air is like mine its on the celing. Here's what was happening. All of those 12v lights you have on is generating so much heat and is being sucked into the cool air return for recycling. After I realized this, I turned off the celing lighs and just like that...the air conditioning became much cooler and we became happier. We lived with the lights on the wall just fine. Hopefulling this will help to cool you off. Good Luck!

12 volt lights do create a lot of heat, the example you gave really is an extreme. If your lights produce enough heat to affect your air conditioning, you might consider changing them out for LED's. They produce almost no heat and are available for not much more than the cost of replacement incandescent bulbs. There's a "sticky" about LED's on the forum.

[kellydog98]

Yup. Done and done. Just relating the experience.

[Bob Landry]

I would also like to see some temperature readings right at the return air grill both with and without the overhead lights. I would submit that you are getting more heat radiated through the roof than the lights are giving off. Temp readings should be done on the same day so there is some control over it. Measure it with the lights off, then turn on the ceiling lights for thirty minutes and measure again You would need to use digital thermometer for the most accurate readings.