Air Conditioner Size Requirement

The compressor failed in our 2287L air conditioner, the OEM installed is rated 13,500 BTU's. I can see from a manufacturing point of view that buying one size A/C unit for all trailers would be more cost effective, but leaves me wondering why it couldn't be replaced with a smaller 9,200 BTU unit. All the calculations and charts I've seen indicate that is possible but if anyone out there has had real world experience I'd appreciate the input. The one we're looking at also has the capability of adding a heating element, which appeals to me that we can save not running the propane furnace.

Ken, or Christine (probably not Useless) - you bring up an excellent question. I'm going to give you my opinion, and others may have different ones. Choose the one you like the most.

Your trailer is 22 ft long, but the living space is less due to the way HiLo measures trailers. I think the "box" is about 19 ft long. (You could measure this if you want). The width of your trailer is about 8 ft. The interior dimensions of both length and width will be somewhat less, but let's use 19x8 as a conservative estimate of the area you need to cool. That area would be 152 sq ft.

Now, I have a portable air conditioner in the guest room of my home which is an A-Frame and is on the third floor. It is about 360 sq ft and the "walls" are the roof. Like most A-Frames, the only insulation is the roof shingles. The air conditioner is rated at 11,000 BTU/hr. It keeps the room comfortable.

Your trailer has less than half the area to cool and has slightly better insulation. I assume it is also painted white, which should help immensely. As a result of this comparison analysis, I'm of the opinion that a 9200 BTU unit would cool your trailer just fine. It would run more often/longer than the old one and would probably take somewhat longer to cool the interior down if it was starting from a hot condition, but those are minor concerns. Running more often, it might even feel more "comfortable", because it would dehumidify the air more constantly than the old one.

The only real issues would be the mounting on to your trailer and water drainage. It probably won't exactly fit the old opening, so you may have to make some adjustments there. AND, you will have to be very careful to duct the water it condenses from the atmosphere away from the interior, or you will have the "interior rainstorm" that has been posted here recently.

Other than those considerations, I think you have a good idea and look forward to seeing the results of your "mod". It should be more efficient and "quieter" than the old one too.

- Jack

I'm sure you know you could use a portable 1500 watt heater to cut down on the use of propane. For me personally the heat strip in an air conditioner is not cost effective when I can get a small electric heater for $30.00 and move it where I need it. When and if I ever need to buy a new AC for my HI-LO I'm going to take a good long look at the Atwood Air Command series of ACs.

hmmmm.
I've used my air conditioner a good deal the last two years as we have been travelling with an aging dog who does not do well with either heat Or humidity. In the midwest- and in the southeast- the humidity is a huge factor. My experience is my 13,500 btu unit is adequate but there have been times when it was barely making it ( 90 degress- 85% humidity). On the other hand- I'm sure it could use some servicing as I dont know how well it is really functioning these days. That said- on our last trip I kept a small fan going on the floor to keep that air circulating for the dog. Thus- in real life usage I find it is not a case where we are climbing into the sleeping bags at night to stay comfortable. I have a friend with a 16ft CAsita and a small "window" type unit. They do find- but the barely-six-feet interior height certainly cuts down on the volume. out WEST, where conditions are much drier, and the night air does not hold the heat as much, a samller unit may do fine as the effort to de-humidify is not as critical and drier hair has a harder time of absorbing heat and holding it. AS far as heat strips- I agree with Gary they don't seem worth it to me.

Rick

AC replacement.

What would be the cost of a smaller unit? The larger units might be cheaper as thousands are sold. Our AC unit was a display model and it came with the AC strip. On our 25ft. unit it wasn't enough to take the chill off on a cold morning. We usually were cooking in the oven/stove topand this gave off more heat. It would be very concerned trying to patch a smaller unit into the roof. Roof leaks are something you want to avoid at all cost.

underpsi said:

The compressor failed in our 2287L air conditioner, the OEM installed is rated 13,500 BTU's. I can see from a manufacturing point of view that buying one size A/C unit for all trailers would be more cost effective, but leaves me wondering why it couldn't be replaced with a smaller 9,200 BTU unit. All the calculations and charts I've seen indicate that is possible but if anyone out there has had real world experience I'd appreciate the input. The one we're looking at also has the capability of adding a heating element, which appeals to me that we can save not running the propane furnace.

Click to expand...

Underpsi, regarding the the heating element you mentioned, the RV dealers call it a "heat strip." We had one installed with our AC. The purpose of the heat strip is to quickly warm up your Hi-Lo on chilly mornings when you get up or when you go to bed at night; it has no thermostat and is turned off after warm up and does not take the place of a furnace or electric heater controlled by a thermostat. The Hi-Lo factory in 2009 charged me $125 for the heat strip and installation. The reason that I wanted it is because I do not live in extremely cold weather during the year, and if I wanted to camp in early spring or early winter, dear husband and I could warm up the Hi-Lo in the morning while dressing and evening while putting on pjs and the rest of the day the camper would be warmed by the sun.

Dee
Summerville, SC

Thanks all, good feedback. The unit we're considering is a Coleman-Mach 8 Cub A/C, one thing I like about it is that it's low profile and a bit more efficient than the 30 year old BriskAire that quit on us.

The exterior length of the trailer is 18', width is 7'7" so the calculation used was 18X8 equals 144 square feet. The charts all recommended 5000 BTU for 150 sq ft or less. The Coleman is 9200. It also fits into the 14"X14" ventilator opening that the current one is mounted in. The unit doesn't have the same footprint as the old one, so I'll have to fill some holes I'm sure, but that's probably the case with anything we buy to replace the old one. The reason we're looking at a new A/C is that I want to replace it now, since we developed some pinhole leaks on our last trip out. I want to KoolSeal the entire roof so timing is good.

The heat strip/heating element is rated at 6000 BTU and is $70 extra. We're dealing with Camping World in Kansas City, so I'll have to ask if it's thermostatically controlled. Hadn't thought of that, just figured it was. We don't camp in extreme cold either, so it would be used to take the chill off without firing up the noisy furnace. We do have an electric oil heater, but it's just one more thing to have to stow before we roll.

Cost is about $400 less than its 13,500 BTU cousin.

And Jack, he's not really "Useless", he's just a mama's dog who would rather sit in a lap than chase sticks or ride in the truck

Useless sounds like a pretty smart dog!

Your reasons for installing the smaller AC sound good to me. I'm not convinced the heat strip will be all that wonderful, but until you give it a try, you won't know.

- Jack

Other than the use of LP gas I would prefer the furnace over the AC heat strip just because the furnace runs quieter than the AC fan. For heat in campgrounds we use a little ceramic cube space heater. It works fine and is very quiet and compact. We sit it on the counter top or on the stove when its not in use.

garyk52 said:

I'm sure you know you could use a portable 1500 watt heater to cut down on the use of propane. For me personally the heat strip in an air conditioner is not cost effective when I can get a small electric heater for $30.00 and move it where I need it. When and if I ever need to buy a new AC for my HI-LO I'm going to take a good long look at the Atwood Air Command series of ACs.

Click to expand...

Gary - Thanks for suggesting the Atwood, it looks like a pretty good unit. Found one that is rated 13,500 BTU but claims 16,000 BTU performance. It might be better here in Mid-America where it's hot and the humidity can be high for days in a row. It's 20 pounds lighter than the nearest competitor and has a remote control with the ceiling unit. If we ever go to generator power, it will run on a 2,000 watt generator. We'll have to check this out at our local dealer. I think we'll just stick with the 1,500 watt radiant heater we already have instead of the A/C heat strip.

-Ken