What size A/C unit?

I've tried letting the air out before and didn't like it. I make a slight turn inside the carport and the tires looked like they were going to come off the wheels. The A/C unit on this trailer is 14" from roof to top of A/C unit. I've measured the Coleman Mach 8 low profile on other trailers and it is only 8" above the roof. I travel to Arizona and Utah but only in the spring and fall so I am not worried about 100 degree temperatures. I think I'll stay with the 13.5K unit and call it good. I was just trying to do the math but like someone said there is a lot of variables to consider...not worth the effort.

Griz14

Residential heat gain calculations are based on ACCA Manual J (Air Conditioning Contractors Association). As has been mentioned, the formulas are structure location and directional orientation specific. Perhaps you could pick a few of your favorite camp sites and find a simplified heat gain calculator online and run the calcs for each location?

Washington 13.5 NP, AZ 15 must have.

Griz14 wrote:
The reason I am replacing the A/C unit is because of clearance issues where I store the trailer not with the unit itself. I bought the trailer knowing I would be replacing the A/C unit with a low profile the same thing I had to do with my old trailer. What my real question is there a formula or something that tells you if you have a trailer with a 8'x22' box and well insulated with fiberglass outside walls what size do you need to cool it if outside temperature is 90 degrees? I think the OEMs install 13.5K in all their trailers from their smallest to 26' due to bulk buying rather than that is what is needed. Just my two cents.

You absolutely don't need anything bigger that 13.5 in your trailer. I have a 26ft BH and my 13,500 has zero problems keeping it cool. We just came back from South Texas for 9 days and we had upper 90's every day and our AC would easily keep the temp at 74 where it was set and it didn't run anywhere near all the time.

SoundGuy wrote:

Griz14 wrote:
The reason I am replacing the A/C unit is because of clearance issues where I store the trailer not with the unit itself.

It seems the lowest profile model out there is the Coleman Mach 8 at 8" in height compared to 12" for the Mach 3 Series ... is 4" really going to make a difference? :@

I think I could let some air out of the tires or something. Seems like a lot of money to throw at a small problem. :h

Griz14 wrote:
The reason I am replacing the A/C unit is because of clearance issues where I store the trailer not with the unit itself.

It seems the lowest profile model out there is the Coleman Mach 8 at 8" in height compared to 12" for the Mach 3 Series ... is 4" really going to make a difference? :@

A small trailer in Washignton State, the 13.5k is probably fine.

If you plan to spend a lot of trips in really hot conditions, I would bump up to the 15k unit for very little extra cost to get a bit more cooling. If it's 100 degrees out, even with a small trailer, it may have difficulty keeping it cool inside.

Mostly done by rule of thumb. To apply a formula takes a lot of variables, how hot outside, how humid, how cold do you want it inside, how good is the insualtion, how often does the door open, is it in direct sun or shade, etc...

The reason I am replacing the A/C unit is because of clearance issues where I store the trailer not with the unit itself. I bought the trailer knowing I would be replacing the A/C unit with a low profile the same thing I had to do with my old trailer. What my real question is there a formula or something that tells you if you have a trailer with a 8'x22' box and well insulated with fiberglass outside walls what size do you need to cool it if outside temperature is 90 degrees? I think the OEMs install 13.5K in all their trailers from their smallest to 26' due to bulk buying rather than that is what is needed. Just my two cents.

Agree that if 13.5 works go with it again. It is possible to have too large an A/C that cools the air so quickly it doesn't dehumidify the air which then feels clammy.

Get rid of the roof a/c and cover the hole with a dome. Then install a window unit that can be sized for your unit.

I hate roof air conditioners. They're noisy, vibrate, consume a lot of power, weigh a ton, and only come in two sizes. Arrgghhh.