AC Unit runs a long time

Yesterday afternoon our AC unit seemed to run forever without getting the temps inside down to the mid 70s set point on the thermostat. It was the first hot day we have had at ~90.

-I have read the rather lengthy post about the tent mod and airflow. I feel like there is adequate airflow from the vents w/ the fan on high and low (running on high yesterday).
-Since reading about freezing coils it has been on high ever since so doubt that is the issue.
-I pulled the filter cover, it appears to have the baffle although I am not 100% sure what I am looking for.
-The output air 'seems' quit a bit cooler than ambient

My question then is, (as I don't think there is anything wrong with the unit) is it possible that it is really that difficult for the AC unit to keep up with the outside temp at 90deg outside temp. Maybe due to not enough insulation.

This is my first RV so this may be just an expectation setting experience.

Thanks.

Is the air coming out of the vents cold? If yes I would guess the coil is not frozen. I have found on hot days 90 + if I turn on the A/C late in the afternoon after the RV has gotten hot inside it can take a few hrs to really get the inside temp down. I will usually set the thermo at about 75 if leaving the RV all day. That way the inside is cool and the A/C doesn't have to work so hard. ( in TX anything under 90 is just warm....)

Mesteve, this is my 2cts on the matter. Yes it was 90* in Big Timber MT. yesterday. If you know it is going to be in the 90's, I would turn the A/C in the AM when the big fiberglass box you stay in is still cool inside. The side walls are only insulated to R7, not R16 or more in your "sticks and bricks". The key word here is "air conditioner" which litterly means to condition the air. If you want your coach to be cool, you have to induce cool air early to condition the walls, ceiling, chairs, rugs and everything in your coach as early as possible. The way an "air conditioner" works....it removes the "Hot" air in the "return air" process. and cools it down. The condensing unit is what removes the "HOT" air. Have you used the "quick cool down" at the A/C unit yet. It will move alot of air to help cool down the coach. It still boil's down to having to remove all the "HOT" air from everything inside first before it will cool the coach. Just for grins and giggles, put your hand over the return air grill in your home, when it is hot, and feel the air moving over your hand. Bet it will be warm until your home starts cooling off. Bob

OK, I will just accept the performance I am getting as normal. It is by no means horrible, but I guess you make certain concessions (Like only one AC unit) for buying an entry level unit.

Several things that will help when it's really hot out and only one A/C...pull down all the shades to help create an insulating void between the window and the shade since I assume you do not have dual pane windows in the Sundance. Also, use the ceiling fan to help circulate the air in the unit...really helps to make it feel cooler.

It's been stated that you will only be able to keep the inside about 15 degrees, at most, cooler than the outside air in most RVs. With one A/C it will run almost constantly trying to keep up with temps above 90 degrees.

Mesteve, one thing that might help you in a pinch. Get a portable fan to help circulate the air better. We have a tower type fan, it seems to help for a quick cool down. A/C in a car works the same way, its just the fact a cars interior space is a lot smaller. One thing I did was to remove the underbelly covering and insulate the doggy doo doo out of the bottom of the BH. I does really help in the cold weather. Im sure that it helps in the heat also. BTW, does the air flow out of the registers seem to be good??

Heck my air conditioners (I have 2) will run almost all of the time in the heat of the Texas day (95 plus). The other day it was 102 and the living room AC ran all day. The bedroom ac did cycle on and off. We keep the temp set on 76 during the day and the bedroom goes to 72 at night. The other day when it was 102 it did get to 77 inside but we keep the blinds closed also. We don't have dual pane windows. We are going to get a sun shade for the rear window and the awning being out helps also.

Thanks, like I said, probably just an expectation setting that needed to happen.

It was 105* the other day and we kept both AC's running all day and the inside was up to about 80-82*.

In a sticks and bricks your AC is considered working well if it keeps a 20-25* differential.

We always turn on the Ceiling fan and have a fan on the floor running when it gets that hot outside. We also open up the baffle on the Livingroom AC so it dumps air directly into the living room.

Found out one thing yesterday when we arrived in Asheville NC. Had the Fantastic Fan Thermostat set to max. It was so hot that it came on and we didn't realize it. Could not get the temp inside below about 85*. Then I heard a noise and looked up the fan was running. Closed it and the AC started to cool down the LR.

BC