Framing in roof tops,what did you use.

scanzel · April 29, 2008, 04:11:23 AM

I am getting ready to cut my roof and install the two air/heat pump Penguin's. My question is I know i need to put some type of framing around the hole to support the unit etc. Did you guys use wood or weld in some metal framing. If you used wood how did you go about fastening it to the existing structure ? I will probably need to do wood as I do not own a welder. Thank You.

FloridaCliff · April 29, 2008, 04:40:46 AM

Steve,

I welded mine in and framed the inside with wood, making it a hair thinner to to allow for adjustment and easier setting of the unit.

If your not cutting any ribs, you may try this. Measure the two pieces of angle that are running the length of the bus, between the ribs.

Make them longer than the opening so you can bend a tab back that can be fastend to the rib. Then do the same to the cross piece and

fasten the tab to the piece you just put in. Get some Sika and apply generously to all connections and over fastners....it wont come

loose.

If your cutting a rib you NEED to reinforce with a welded piece.

Cliff

scanzel · April 29, 2008, 07:01:18 AM

Thanks Cliff, I won't be cutting any ribs etc. Sounds good to me sort of my thoughts on what you stated. Wanted to make sure everything was supported.

prevost82 · April 29, 2008, 09:49:22 AM

I used 1 1/2 sq tubing.
Ron

belfert · April 29, 2008, 09:53:16 AM

I cut through a roof rib, but my ribs are really thin metal that is not tubular or anything. I welded in a frame made from tubular steel that should be stronger than what was there.

Dina uses a regular full frame at least in the rear. I don't believe the body is as important to strength as other buses.

Stan · April 29, 2008, 11:42:27 AM

f you cut any longitudinal members, such as one in the center, you have to replace it with welded in supports on each side of the new opening.

H3Jim · April 29, 2008, 02:27:25 PM

I don't think he is going to cut an ribs. He just wants to have a p;eice between teh roof skin and the ceiling skin so when the air conditioner is compressing, it has something to compress against.

I just used wood, with several coats of urethane to keep it from absorbing any water. Since I put them up before the last coat fully dried, the natural tackiness held it in place. When the air conditioner is clamped down, its more than enough to hold it in place. I didn't cut any ribs either. Its been several years and no leaks or loosness.

Ednj · April 29, 2008, 06:45:06 PM

Quote from: scanzel on April 29, 2008, 04:11:23 AM
I am getting ready to cut my roof and install the two air/heat pump Penguin's. My question is I know i need to put some type of framing around the hole to support the unit etc. Did you guys use wood or weld in some metal framing. If you used wood how did you go about fastening it to the existing structure ? I will probably need to do wood as I do not own a welder. Thank You.

H3Jim · April 29, 2008, 06:58:34 PM

nice job ed

Stan · April 30, 2008, 05:20:49 AM

That is the correct method when cutting roof stringers. Maybe the moderators can put your pictures in the appropriate section where it can be referred to when this frequently asked question comes up the next time.

Oregonconversion · February 10, 2009, 03:28:30 PM

Can one of these in roof AC units also provide heat for my coach? Thus eliminating my need for duct work and a furnace?

Also can they run off 110 and propane?

pvcces · February 10, 2009, 09:18:34 PM

Make things easy on yourself and use a low current heat pump; the heat strips tend to be useless and very inefficient.

At least, if I was replacing our current AC, that's what I intend to use. But, if I should decide to do better than that, I would install a 120 volt one ton split system.

In either case, you could make out best if your unit would run on your inverter. You would need to test the electronics. That way, you could use it anytime that you liked.

For what it's worth.

Tom Caffrey

JackConrad · February 11, 2009, 05:41:35 AM

Quote from: Oregonconversion on February 10, 2009, 03:28:30 PM
Can one of these in roof AC units also provide heat for my coach? Thus eliminating my need for duct work and a furnace?
Also can they run off 110 and propane?

Roof top AC un its are available with optional heat stips or heat pumps. They require 120 AC power. None with operate off propane. Whether they will heat you bus depends on sveral variable including outside air temperature, how well you coach is insulated, how many air leaks in your coach, wind speed and direction, etc. Jack

pvcces · February 11, 2009, 07:10:08 PM

What I was getting at is that most heating can be done by a heat pump, and you need a backup heat source for surprises. The only thing changing the capacity does is change the balance point, that is, the temperature at which the heat pump is running full time.

We were really surprised how well heat pumps work here in southeastern Alaska. Having a normal temperature of around 50 degrees results in very good utilization of our units. So far this winter, we have needed backup heat only one night.

For what it's worth.

Tom Caffrey