Hey everyone! I am new here and was hoping to get some guidance about an AC issue in my 26-foot travel trailer. I turned it on for the first time this year and noticed it wasn't cooling well. It was blowing coolish air, but not cold, and was not cooling the trailer much at all. I live in the trailer full time and definitely need ac as our temps can get pretty warm here in the summer (no shade available for parking either). I am wondering if I could just use a portable AC instead, or if it would be better to have the rooftop unit replaced (I am not at all handy so I would need to hire someone). I don't have a lot of cash flow at the moment, so I am looking for the most economical solution. Is it advisable to use a portable ac in a travel trailer safely and efficiently? If so how many btu's would I need for a 26-footer? Thanks in advance for your help!

If you use a portable, you would need at least 1.5 times the btu capacity of your roof mounted unit because portable units are MUCH less efficient.You probably have a 15,000 btu unit. 20,000 to 25,000 btu portable units are quite rare. Check Lowes, HD and Amazon. They would probably run $400 to >$800. It should be worth getting your built in unit repaired. At least get a couple of estimates.

Portables just flat out suck. If you sit right in front of the portable it might cool you down. The downside of a portable is it has to exhaust the hot air to the outside that it creates when cooling. This causes a negative pressure inside so the new hot outside air gets pulled into the trailer to relieve the vacuum.

opnspaces wrote:Portables just flat out suck. If you sit right in front of the portable it might cool you down. The downside of a portable is it has to exhaust the hot air to the outside that it creates when cooling. This causes a negative pressure inside so the new hot outside air gets pulled into the trailer to relieve the vacuum.That is true of single-hose units, which I agree are just about useless because of the pressure differential you mention. If you get a dual hose unit, it both draws and exhausts air outside. No pressure differential with those.

Older portable units did suck. the new roll around units often have a higher efficiency rating than the RV rooftops and do NOT suck air out of the space. They have an inlet/outlet duct for the window so they don't suck air out of the room.Check around and see what you can find. The good ones aren't cheap. Cheap or Good, pick one.

Thanks for the feedback. Sounds like it may be worth getting an estimate to see about getting the rooftop unit repaired. No sense in buying a portable if it won't do the job. Do regular HVAC companies work on these type of units or is it best to try and find a mobile tech for RV's/travel trailers specifically? I just watched a video on cleaning and maintaining rooftop units. I am going to clean it and see if it will help it to cool better. I have no idea if a dirty unit could cause it to not blow as cold, but I figure it couldn't hurt to try.

Rooftop AC Unit Not Cooling Well | Good Sam Community

Moochie
Explorer
May 09, 2023
If you use a portable, you would need at least 1.5 times the btu capacity of your roof mounted unit because portable units are MUCH less efficient.

You probably have a 15,000 btu unit. 20,000 to 25,000 btu portable units are quite rare. Check Lowes, HD and Amazon. They would probably run $400 to >$800. It should be worth getting your built in unit repaired. At least get a couple of estimates.
opnspaces
Navigator II
May 09, 2023
Portables just flat out suck. If you sit right in front of the portable it might cool you down.

The downside of a portable is it has to exhaust the hot air to the outside that it creates when cooling. This causes a negative pressure inside so the new hot outside air gets pulled into the trailer to relieve the vacuum.
F_B
Explorer
May 09, 2023
opnspaces wrote:
Portables just flat out suck. If you sit right in front of the portable it might cool you down.

The downside of a portable is it has to exhaust the hot air to the outside that it creates when cooling. This causes a negative pressure inside so the new hot outside air gets pulled into the trailer to relieve the vacuum.

That is true of single-hose units, which I agree are just about useless because of the pressure differential you mention. If you get a dual hose unit, it both draws and exhausts air outside. No pressure differential with those.
ktmrfs
Explorer II
May 09, 2023
Older portable units did suck. the new roll around units often have a higher efficiency rating than the RV rooftops and do NOT suck air out of the space. They have an inlet/outlet duct for the window so they don't suck air out of the room.

Check around and see what you can find. The good ones aren't cheap. Cheap or Good, pick one.
Raven33
Explorer
May 10, 2023
Thanks for the feedback. Sounds like it may be worth getting an estimate to see about getting the rooftop unit repaired. No sense in buying a portable if it won't do the job. Do regular HVAC companies work on these type of units or is it best to try and find a mobile tech for RV's/travel trailers specifically?

I just watched a video on cleaning and maintaining rooftop units. I am going to clean it and see if it will help it to cool better. I have no idea if a dirty unit could cause it to not blow as cold, but I figure it couldn't hurt to try.
MFL
Nomad II
May 11, 2023
A recommended mobile tech would be best choice for diagnosis.

How old is your AC? A good cleaning would make it cool better, if it appears to need it. A lot can be learned from watching the right videos.

Are you sure it is getting the required power to operate it? Using an extension cord, can keep your AC from cooling like it should.

Jerry
Raven33
Explorer
May 11, 2023
Jerry, I have contacted a few mobile tech's and am waiting to get on the books with one of them. One tech told me that I probably need a new AC and the other said a good cleaning could lower the air temps by 7-10 degrees (obviously going to try that first). It's a 2006 and I'm unsure of the previous maintenance, so there is definitely a chance it could use a good cleaning. I think it's getting enough power as it is plugged directly into the side of a shop (no extension cord). Hopefully a cleaning will do the trick. It's going to be in the upper 80's here next week. I found someone who is going to let me use their portable AC until the rooftop unit is repaired. It's amazing how hot it gets inside these things when the temps go up!
wnjj
Explorer II
May 11, 2023
If it was working well last season and doesn't this one, it's likely not going to be helped with a cleaning. There's little to be lost in trying though.
MFL
Nomad II
May 11, 2023
Raven33 wrote:
Jerry, I have contacted a few mobile tech's and am waiting to get on the books with one of them. One tech told me that I probably need a new AC and the other said a good cleaning could lower the air temps by 7-10 degrees (obviously going to try that first). It's a 2006 and I'm unsure of the previous maintenance, so there is definitely a chance it could use a good cleaning. I think it's getting enough power as it is plugged directly into the side of a shop (no extension cord). Hopefully a cleaning will do the trick. It's going to be in the upper 80's here next week. I found someone who is going to let me use their portable AC until the rooftop unit is repaired. It's amazing how hot it gets inside these things when the temps go up!

Another question...were you using this same outlet on the side of shop last year, with good results?

An RV30 outlet would be great, but a 20 amp outlet will work. A household 15 amp, not a good choice to run AC.

Also, if another large draw from something in the shop, it can lower power available to your unit. Any reason for AC to be short of power needed, will cause less cooling, and eventually ruin the AC unit.

A tech will advise though, concerning cleaning, or enough power.

Hope you get it figured out, as you are right, as to getting hot inside quickly.

Good luck,
Jerry
poppa
Explorer
May 16, 2023
my less than three year old rooftop slowly quit cooling new aint always better. put a tap on the suction line and put some snake oil leak stop in it with refrigerant and still cooling. cant, couldnt find leak but so far so good. was able to do it my self though.