Question 1 - Air conditioner struggles to cool camper

[samhain7]

Had an interesting weekend so question 1 of 2.

Our trailer in my sig was struggling to keep cool.
In Toronto it hit 86F (30C). The trailer was parked between two medium sized trees so go SOME shade. Our Air conditioning unit was really struggling. I used my laser temp reader and the housing of the output on the air conditioner vent was around 55 degrees. Is that normal cooling operation?
The air conditioner was set to 74 and the lowest it got was 77 degrees and that was running non stop.

[samhain7]

Just updating on our recent trip. Sealing up the vents and the baffle with foil tape made a huge difference. Air flow was great and the trailer cooled a lot quicker and maintained the temp easier...

[samhain7]

I tried to respond to this earlier. But my browser wouldn't let me.

Anyway I looked in the unit over and over and then I finally noticed. And probably as smkettner was typing his response. I notiecd the baffle between intakes was at a 70 degree angle. So essentially 30 percent or more of the cool air was recirculating.
Fixed it and sealed it with foil tape and air flow is dramatically better. Will it help me on a hot day? We'll see I guess.

Funny , I am very handy at home in fixing everything. But I sometimes don't apply the same principles of troubleshooting when working on my RV.

[GaryWT]

Generally I do not have issues but one week it was in the 90's all week. I set the ac at 65 or so and the first night it was still warm at bedtime but by morning the trailer was cool and then it was able to keep up for the most part, getting just a little warmer mid afternoon. All in all it was fine.

[RedRocket204]

smkettner wrote:
Do check the interior install. Remove the interior trim and take a look for poorly sealed transition to the ducting. Also verify if you have a plenum divider that it is well placed and sealed properly. This divider separates the air coming in and going out. If it is not installed well some of the air can just circulate within the unit.

Bingo. Exact issue I was having after the TT has shifted multiple times from traveling. Just needs a "tune-up". I did what was recommended and sealed the area really well with aluminum tape and it made a big difference.

Roof AC not cooling properly. Check, test and fix

[Tachdriver]

Last year I was at a campground in Eastern KY, it was upper 80's to 90's and very HUMID.

Late afternoon my AC kept on running at set for 74, it would not cool down enough to cycle. Open and closing the entry door brought in more heat. I had no shade either.

Not uncommon but covering windows, put plug pillows in my roof vents etc helped out.

[hohenwald48]

Restriction of the ducts will result in the symptoms you describe. If the a/c is only putting out half its rated airflow of 55 degree air it will never cool the trailer. Also, I've seen duct work come loose and dump all that cold air into the space between the ceiling and the roof. That won't go far toward cooling the trailer.

If you have a snake camera I'd stick it down thru all the vents and ductwork looking for leaks or obstructions. I sure wouldn't intentionally obstruct any of the outlets.

I have a 21' trailer (with two large slides) with a 15K BTU a/c and I can get it so cold you need blankets watching TV when it 100 outside. Granted your trailer is longer but it seems to me it should cool better than that.

Also, some units come from the factory with a poor sealing job between the return and supply chambers in the a/c itself. That seal (usually just tape) can deteriorate over time and cause cooled air to simply recirculate within the a/c and provide no cooling to the TT. Pull your filter panel to take a look at that area.

[time2roll]

Probably normal, mine is similar. Did you start in the morning or arrive hot and expect it to cool down? Best to start early and many just do not have the BTU required to hold 72 in all conditions. Very common to run non stop during the heat of the day and until the sun drops before it cycles.

Do check the interior install. Remove the interior trim and take a look for poorly sealed transition to the ducting. Also verify if you have a plenum divider that it is well placed and sealed properly. This divider separates the air coming in and going out. If it is not installed well some of the air can just circulate within the unit.

[samhain7]

One thing I notice too, is that the roof vent out put much different air pressure.
I have two vent that goto the back of the trailer and the air comes out there pretty good.
I have 4 vents to the front and the air doesnt come out very good even if I close the two back vents. I checked the vent with a camera and it is not obstructed.
When I bought the trailer, it was weird. The front 4 vent output from the AC unit was sealed off with foil tape.
I am thinking on blocking off part of the back to vents input from the AC to push more air to the front vents. Maybe more air distribution will help (assuming there is nothing wrong with my AC unit and it is functioning normally.

[Big_Katuna]

Its not the temp of the air coming out that matters; its the DIFFERENTIAL that you measure.

It should be between 20 and 30 degrees colder than what is going in.

When you turn it on and its 95 degrees in there you would expect 70-75 degree air coming out. As it keeps lowering the ambient temp, it will keep cooling the room down until it hits the thermostat set point.

If the door was getting opened much or a side was facing west, sounds normal.

[geneeich]

I'm having the same issue. Air out of my vent was 64 as my house. Unit was not icing up. Do I need a bigger or another AC unit?

[samhain7]

Thanks for the replies!
My trailer is a 28 footer.

[DownTheAvenue]

KD4UPL wrote:
Should have worked better than that. Should have been putting out colder air than that. Have you cleaned the filters and the fins up under the shroud? I'm guessing it's low on refrigerant. That would normally indicate a leak.

This is totally wrong.

A 30 degree differential between outside ambient air and output air shows the A/C is working properly.

The problem is the heat gain of the trailer exceeds the cooling capacity of the A/C. This is usually caused by poor insulation, lots of windows especially facing the sun, and/or parked in the sun.

[timmac]

RV's do not have very much insulation like a home does, look how thin your walls are that ought to give you a clue, also what is the length of your RV, maybe one AC is not enough, mine is 32 foot long with 2 AC's, 55 degrees out the vent might be ok but the AC can't cool much better if heat is getting into the RV thru the thin walls and single paine windows.

[Community Alumni]

I set mine to 68F and it will cool down. Once the temperature gets to around 72-73F , I set it there and it will cycle on & off as needed. Out trailer is 33' inside.

This past weekend we had outside temps in the high 80's on Friday and 91 on Saturday, it was fine after a couple hours.