Recommendations for a roof mount AC

[MXD]

I'm just about done bracing my trailer roof so that I can mount a nice roof mount AC unit up there for the summer. I race moto so it can get pretty hot at the track during the summer. You can see from the picture, what I did to brace it. In the picture, the supports were just cut and laid in place to test fit (I did the whole roof BTW, I just don't have a pic of it all done). I have since pulled them all back out to prime and paint them and added some block bracing. I also framed in around the 14x14 opening. My question is, what unit/manufacturer would you guys recommend? My main concern is durability and reliability. I'm going with a 13.5K BTU.

[swoody126]

b4 you go too far figg'r out how you are going to INSULATE it & work that into the overall plan

sw

[Hader]

From my own past experience: Roof Mounts are expensive to buy, loud, pain to maintain and expensive to fix.
If your layout allows it, go with through the wall or floor window unit.

[swoody126]

have you looked into roof mounted units w/ a heat strip in them?

they do double duty and don't take up any floor/wall space

btw, the roof mount on my tt is 14 years old and the only repairs i have had was when a squirrel chewed some wires and the regular filter cleaning

sw

[MXD]

b4 you go too far figg'r out how you are going to INSULATE it & work that into the overall plan

sw

I have a plan to insulate it but I'm going to hold off and see how it does. Every track we race at has tree cover in the pits which helps. I have used a free standing unit in the past and it has done an ok job. Not great but ok and it was a small unit so I think the 13.5 will be fine. But if not, I'll insulate it and skin it. I'm going to leave it exposed for now. I'm in the northeast so 90's are not so common. Maybe a handful of weekends.

[MXD]

From my own past experience: Roof Mounts are expensive to buy, loud, pain to maintain and expensive to fix.
If your layout allows it, go with through the wall or floor window unit.

Loud isn't an issue as I'll be at a racetrack. As far as a wall unit, I will go to great lengths to not cut through my walls. It's something I'm scared of. I'd rather spend the extra $4-500 for a roof set up.

[MXD]

have you looked into roof mounted units w/ a heat strip in them?

they do double duty and don't take up any floor/wall space

btw, the roof mount on my tt is 14 years old and the only repairs i have had was when a squirrel chewed some wires and the regular filter cleaning

sw

I considered a heat strip but the race season goes from late April to early October so the need to heat isn't that great. I have a little Mr. Buddy heater that I use on the 1 or 2 cold days a season and it keeps it nice and toasty without the need for a genny.

[McDave]

Hey MXD,
I have the Coleman Mach III with the heat strip. It works really well as a cooler and it has a Cool hi/low fan speed, hi/low fan only option and low heat setting. As for the heater, its only about 1500 watts and you seem to lose some of that to the machine and the fact that it is not air tight between the compressor/condenser side and the evaporator/heat strip side. Also the heat comes out at roof level, and since heat rises it takes a while before enough air has cycled through to feel the heat if you are sitting. Stand up and you've got a hot head. But if you just need to take the chill off, say it's 50f inside, this will work nicely. As I write this, it is -4f and we are hoping for a high of 7f today. Balmy for Montana, but the heat strip would be basically useless now. I have a little ceramic heater that is only1100 watts with a fan and it works much better.
This is the only rooftop A/C I have any experience with so I cant speak to the Dometic or Atwood. 135000btu is plenty. We're only talking about 100sqft or less and I have it well insulated. Dollar for dollar the best thing you can do is paint the roof with Henry 587 Reflective roof paint. About 35.00 per gal., covers 100sqft, double coats. The difference was remarkable. Like 35 degrees in July.
The A/C fan is a little noisy and since it located at head level when standing, there is no avoiding it. but it does cool it down quickly.
Seems like it weighed 100-125 lbs. I used 1.25 square tube welded in around the 14 x14 hole where the roof vent was.
It is nice to have it located on the roof since space inside is limited to begin with, keeps it safe and out of the way. IMHO, the right tool for the job. The window A/C idea works, somewhat, but you get what you play for. Just sayin'
Hope this helps,

McDave

PS. Here is the install PDF....
http://www.1willwander.com/2013/07/cole ... ation.html

[MXD]

Hey MXD,
I have the Coleman Mach III with the heat strip. It works really well as a cooler and it has a Cool hi/low fan speed, hi/low fan only option and low heat setting. As for the heater, its only about 1500 watts and you seem to lose some of that to the machine and the fact that it is not air tight between the compressor/condenser side and the evaporator/heat strip side. Also the heat comes out at roof level, and since heat rises it takes a while before enough air has cycled through to feel the heat if you are sitting. Stand up and you've got a hot head. But if you just need to take the chill off, say it's 50f inside, this will work nicely. As I write this, it is -4f and we are hoping for a high of 7f today. Balmy for Montana, but the heat strip would be basically useless now. I have a little ceramic heater that is only1100 watts with a fan and it works much better.
This is the only rooftop A/C I have any experience with so I cant speak to the Dometic or Atwood. 135000btu is plenty. We're only talking about 100sqft or less and I have it well insulated. Dollar for dollar the best thing you can do is paint the roof with Henry 587 Reflective roof paint. About 35.00 per gal., covers 100sqft, double coats. The difference was remarkable. Like 35 degrees in July.
The A/C fan is a little noisy and since it located at head level when standing, there is no avoiding it. but it does cool it down quickly.
Seems like it weighed 100-125 lbs. I used 1.25 square tube welded in around the 14 x14 hole where the roof vent was.
It is nice to have it located on the roof since space inside is limited to begin with, keeps it safe and out of the way. IMHO, the right tool for the job. The window A/C idea works, somewhat, but you get what you play for. Just sayin'
Hope this helps,

McDave

PS. Here is the install PDF....
http://www.1willwander.com/2013/07/cole ... ation.html

Thank you, that's very helpful.

[nunrleft]

I've got a Dometic 13500 w/heat strip and a remote thermostat in mine. You can read about my build in the link below. Knowing what I know now (noisy and higher power requirements) I probably wouldn't do a roof mount again. I'd install a small door to stick the back of a cheap window unit out of. Most likely at counter height in the front so the window unit could sit on the front counter and have the rear sticking out of the open door. A door installation will be much easier than installing a roof mount a/c.

[MXD]

I've got a Dometic 13500 w/heat strip and a remote thermostat in mine. You can read about my build in the link below. Knowing what I know now (noisy and higher power requirements) I probably wouldn't do a roof mount again. I'd install a small door to stick the back of a cheap window unit out of. Most likely at counter height in the front so the window unit could sit on the front counter and have the rear sticking out of the open door. A door installation will be much easier than installing a roof mount a/c.

Since I will only be using it at a race track, the noise is a non factor. I also already own a pair of EU2000 Hondas so power is not an issue either. Other than those 2 things, What other negatives did you experience? My roof is all braced and framed out for it and there is already a pass through plug for the generators so all I have to do is wire the unit to the panel. I would think at this point, cutting a hole in my wall and framing that all out would be a much larger task than heaving a 100 pound AC unit onto the roof and mounting it. Am I missing something about the install?

[Hader]

Installation of a rooftop Ac is no big deal.
One of the reasons that I choose a window unit is this: I get to camp late Friday afternoon, then I discover that my AC is not working. I'd rather go to the nearest Walmart and pick-up a new one for $120 or less than having to wait till Tuesday for a part, and, spend the whole weekend with no AC.

[nunrleft]

Since I will only be using it at a race track, the noise is a non factor. I also already own a pair of EU2000 Hondas so power is not an issue either. Other than those 2 things, What other negatives did you experience? My roof is all braced and framed out for it and there is already a pass through plug for the generators so all I have to do is wire the unit to the panel. I would think at this point, cutting a hole in my wall and framing that all out would be a much larger task than heaving a 100 pound AC unit onto the roof and mounting it. Am I missing something about the install?

My mistake. I thought I saw beds in your picture. But since you won't be trying to sleep with the air conditioner running you'll be just fine with the ceiling unit.

[MXD]

Since I will only be using it at a race track, the noise is a non factor. I also already own a pair of EU2000 Hondas so power is not an issue either. Other than those 2 things, What other negatives did you experience? My roof is all braced and framed out for it and there is already a pass through plug for the generators so all I have to do is wire the unit to the panel. I would think at this point, cutting a hole in my wall and framing that all out would be a much larger task than heaving a 100 pound AC unit onto the roof and mounting it. Am I missing something about the install?

My mistake. I thought I saw beds in your picture. But since you won't be trying to sleep with the air conditioner running you'll be just fine with the ceiling unit.

Ah, I see. Yes, you are correct, those are a pair of jack knife couches that fold out to make one big bed. Occasionally I do sleep at the track but they have strict rules about no generators after 10pm. So no matter what, I can't run it at night anyway. My main objective is to stay cool while all suited up between motos on those 90 degree days.

[nunrleft]

One other thing, my 13500 Dometic Brisk Air II has a minimum generator rating of 4500 watts. So technically your two 2000 watt Hondas wouldn't be enough. Whereas a window unit would probably operate on one of your generators.