Installing Rooftop ACs

[Dakell12]

Hello everyone, I am trying to install 2 13500 BTU units in my bus, but because of the overhead steel I beam down the center of the roof, I am thinking I need to mount it in the overhead emergency exits which measure 15.5 x 22 inches. They make shrouds that measure 14.5 by 21, so i was wondering if anyone has experience with filling that gap, and how to do so. Is the other option off-centering the units?

[Dallas]

Dakell,
I think I would just cut some new 14 12/" X 14 1/2" holes off center and mount them.

If the bus ever decided it was sleepy and laid down on it's side, you would be VERY thankful to have the escape hatches still functioning. Also, when you don't need A/C, but want fresh air, you can open the hatches.

Everyone has their preferences, but those would be mine. YMMV.

If you decide to put the carbuncles down the center, make sure you box in the holes you cut with steel from one cross member to the next to keep the structural integrity of the bus.

Dallas

GO BUSSING!

[/i][/b]

[bus05eagle]

Dakell,if your bus ceiling isn't finshed its easy to install the 14x14 squares i think the airs look better when on the center

[Nick Badame Refrig/ACC]

Hi Dakell12,

Dallas is giving you good information!

If you offset the A/C's to the drivers side, you won't be bothered by that anoying condensation water dripping

down the side of your bus where you are sitting and having your favorite beverage.

Good Luck
Nick-

[H3Jim]

I don't believe there is any reason you have to cut the center beam when installing the roof airs.  Its not that wide, and all the air flow will  go around it.  The 4 bolts that hold an air conditioner to the roof would not have a conflict either - they just go in each corner.  Just cut two rectangles, about 6" x 14" each and leave a 2" strip in the middle (or however wide your beam is)

I would not use the escape hatches as air conditioner holes.  They are generally too large and require some work to fill, it can be really handy to have access to your roof both for access and for safety.  If you don't use the hatches, you also more flexibility about where you place the airs - whether it be for wiring or air flow or headroom.

I personally off set them, and after I went with the  low profile for the roof, and made a centered box on the inside, there is not much funny or bad looking about them.  By having them offset, I was able to put solar panels on the one larger side, saving precious roof real estate for all the junk I have and still want to put up there.

[H3Jim]

picture of my front roof air.  while obviously offset, I don't think it looks bad.  The taller Carrier looked really ridiculous when I had it up there.  It is narrower and about twice as tall.

[bus05eagle]

Jim yours don't look bad but i have seen some that do look bad i should stay out of this since i have 3 cruisairs and nothing on the top anyway

[belfert]

The size of the shroud does not relate to the size of the opening into the bus.  The opening into the bus should be 14"x14" or you will have leaks.

Others may chastise me, but I cut through the center roof beam to install my roof AC units.  I built a welded box of much heavier tubular steel and welded that into the opening to reinforce the area I cut out.  The center beam was just some 14 gauge or so formed sheet metal.  It was not tubular or anything and is not really a beam.

[NJT5047]

May I suggest that if you offset the units, use the center beam as the  medial mounting surface.  In other words, cut right down beside the center beam and frame the other 3 sides.   ACs need relatively flat sealing surfaces for the best fit.  As has been mentioned, keep them on the street side of the coach..or it'll "rain" in hot humid weather on your patio.
Read a recommendation to mount over the center beam without cutting it out...while that may work with some AC units,  wouldn't work with some Dometics.  Don't know about Coleman and Carrier.   My Dometics have tiny airducts that are custom cut to fit according to roof thickness..and where else...right in dead center. 
Low profile units probably wouldn't be too odd looking if offset. 
By the time you frame up 3 sides, you could almost fab a center hole.
Or, go with basement ACs.  That will keep the bus symmetrical.  Basements my cause a little asymmetry in your wallet. 
Best, JR 

[Danny]

I am getting ready to install two 15000 AC probably this weekend in my MCI 102A3.  I have the same concerns.  I am, however, going to use the hatches for the AC.  It just makes sense to me to use the holes that are already there...

Danny

[DavidInWilmNC]

First off, I couldn't have mounted my front A/C in a hatch, as MC-8's don't have front hatches.  Even with that, I think I'd definitely leave at least one hatch operable.  It's so much easier getting up on the roof without having to mess with ladders, etc.  I was able to get my Carrier HP up on the roof through the hatch... much easier that anyother way I could find.  My front A/C is offset like JR mentioned.  The center beam is one side of the frame and a cross member is the front part.  The rest is framed in treated 2x4.  After I cut the hole in the roof, I figured out that I could have mounted the A/C so it would straddle the beam like Jim suggested.  I'd fill that section of frame with expanding foam if I were going to do that.  Good luck with the A/C's.

David

[TomC]

On my AMGeneral transit, it also has the metal beam running down the center.  I don't like to alter bus structure, so my A/C's (3) are offset.  This actually worked out fine since my bath is 4ft wide, then a 2ft hallway then 2ft for closets/washer-dryer/reefer.  The rear A/C and mid A/C are offset on the left and aligned in the middle of the hall.  The front is offset to the right to have a better angle to blow directly on the driver.  Course my roof is alot less curved, but it works for me.  Good Luck, TomC