Community Forums

Muddflap · 05-29-2018, 09:18 PM

I’m so glad I have 3 15K A/C units on my RV!!!

Bob Hyatt · 06-04-2018, 09:17 PM

The often cited 20 degree differential is NOT the differential between inside the coach and outside. It is the difference between the A/C air intake air temp and the A/C discharge air temp. 18-20 degrees is the expected range for a normal house A/C as well. In 100+ degree temps here in Alabama, my house stays at whatever temp we set, down to a low of 72 which is a bit cool for us older folks.

My tiffin shows the same 20 degree differential, but we had it in the driveway this past weekend with outside air temp at 99 degrees, inside air temp at 71 degrees... This 32SA has a 15K BTU front A/C and a 13.5K BTU rear unit. It's enough to run us out pretty much, without breaking a sweat...

Bob_C · 06-04-2018, 09:48 PM

Could always use a portable one....

Daverene · 06-05-2018, 05:36 AM

Be careful with a portable unit it will put the coach in to a negative. So here in Florida it will be cool but muggy inside the coach.

SarahW · 06-05-2018, 03:34 PM

Quote:

Originally Posted by Daverene

Be careful with a portable unit it will put the coach in to a negative. So here in Florida it will be cool but muggy inside the coach.

I don't understand your comment. "Put the coach into a negative"...?? A negative what?

Sweetbriar · 06-05-2018, 04:03 PM

Quote:

Originally Posted by SarahW

I don't understand your comment. "Put the coach into a negative"...?? A negative what?

Over air condition might be a better term. Happens when you over size the system for the load. Drops the temp faster than it can pull the water out of the air. End result is a cold clammy living area that feels like a cave.

I would drop the ceiling unit and inspect the fins on the evaporator. Doesn't take much dirt on the fins to compromise the system capabilities and the air filters are usually less than good regarding filtering out crud. Same goes for pulling the top cover and ensuring the condenser is clean and straighten out any bent fins with a fin comb. Every little bit helps.

https://www.amazon.com/SUPCO-FCR6-He...70_&dpSrc=srch

Podivin · 06-05-2018, 05:11 PM

Quote:

Originally Posted by SarahW

I don't understand your comment. "Put the coach into a negative"...?? A negative what?

Portable unit exhaust a LOT of hot air.
To exhaust air they have to bring it in from somewhere, or there would be negative pressure inside the RV. So they are bringing in outside air as fast as they are pumping out hot air, you rapidly get to a point where they aren't doing much good.
Two hose units don't have that problem.

Bob_C · 06-05-2018, 05:21 PM

Google portable A/C units.......Ones I've glanced at use one exhaust hose and come with a window kit, which could be exhausted out a roof vent, and a lot of different sizes

Daverene · 06-06-2018, 05:21 PM

The exhaust of the portable unit out the window causes the coach to become neitive ie low pressure in side the coach. So out side air starts rushing in threw every crack and crevice. That causes that cool but wet feeling. The roof top unit pull air in and blow out into the exact same space so no negative pressure.

SarahW · 06-06-2018, 06:25 PM

Quote:

Originally Posted by Daverene

The exhaust of the portable unit out the window causes the coach to become neitive ie low pressure in side the coach. So out side air starts rushing in threw every crack and crevice. That causes that cool but wet feeling. The roof top unit pull air in and blow out into the exact same space so no negative pressure.

JtSpain · 06-08-2018, 12:19 PM

Be sure to check the dividing baffle between the return air / supply air. The baffle between the two on our rooftop air unit was poorly installed. Once I went in and placed an appropriate separation and taped the gaps with foil duct tape the AC went from constantly struggling to cooling the motorhome pretty quickly.

Mudfrog · 06-08-2018, 11:34 PM

Ours is right at 28 feet in length. I opted for the larger rooftop unit when we bought it. Had it out last week in 95° weather and it did fine. It did run more but it was able to keep the temperature where we wanted it. This was with partial shade.

From firsthand experience with a shorter coach, I don't think the 13,5 would have been able to keep up. At the same time, I have a feeling the 15 might struggle somewhat with the additional 3 feet of coach the OP has.

avfordguy · 06-09-2018, 10:02 PM

Quote:

Originally Posted by vsheetz

Add a second unit. Might be able to install in a vent opening. Even a through wall unit with separate plug direct to the pedestal.

Called fleetwood, said there is mot enough roof support for a 2nd ac in rear bedroom, i find that hard to believe

txcpl · 06-10-2018, 04:31 AM

One of our close camping couples is having issues with their 13,500 btu AC unit in their 31 ft. Itasca Class C. They took it to our local RV repair shop and were told that for almost the same cost, the shop would install a second AC unit in the bedroom, and run the electrical connections outside the camper so a 20 amp cord would be used to power that AC unit.
FYI