Roof Wart Install

[Eric]

Well the heat is finally getting too us...my makeshift basement air just isn't cutting it and the wifey gave me the "if you don't get me A/c you can sleep on the floor approach" I've pulled the ceiling panel where i want it..anything special for cutting through the roof? Any Preferable tool for doing so? I got my hands on some old Mach units for FREE so i had them serviced, rebuilt the fan motors and plan on using one of them for now...suggestions ideas babblings on install would be appreciated!

[Melbo]

angle grinder to cut with BUT I would also make a plan for a drain to get rid of the condensate so it doesn't run down the side of the bus and if you have an MCI -- I didn't notice what kind of bus you have -- and you don't make plans for the condensate position the units to the drivers side for the run off

Just my opinion

Melbo

[buswarrior]

Yup, tuck it up against the driver's side centre roof support. Cut the hole neatly with whatever your weapon of choice is.

Leave the roof ribs in one piece...

You might consider fabricating a wood base to level it somewhat, and dampen the noise. Many of the old timers swear by mounting the AC on wood to help with noise control.

Shhh, don't tell her that it is cooler sleeping on the floor....

happy coaching?!
buswarrior

[luvrbus]

They way I do it is make a 3 sided metal frame and attach it to rib use rivets, bolts or weld it either side of rib whichever works also if your Neo has a hatch frame it there if it will work for you a 14x14 opening


good luck

[robertglines1]

one problem I had with the basement air was getting warm air off ceiling...Installed ceiling fans and helped problem...brought hot air down and mixed with cold...would be 60 on floor and 90 on ceiling...mixed two and got more consistent 70 ...putting the roof air in will do about the same thing by getting the warm air off the ceiling..and circulating..

[Dreamscape]

We have three roof warts and they really do a good job. It's been in the high 90's here for the past several weeks, run one on low during the day with the back half of the coach closed off. Turn the other one in the bedroom and it's cooled off in minutes. I checked the temp from floor to ceiling and only found a 5 degree difference. We have yet to turn on all three, that would make the meter go nuts!

I'd just use a grinder to cut your hole, clean the surface real good and lay down some butyl tape. I installed some wood between the roof and our regular ceiling for added support when I redid the interior. Ours was already cut in the roof when we got it, and they are in the middle. They are several years old and still going strong.

I know they are ugly, but they do the job!

[Eric]

So a grinder is my best bet then? I figured you guys came up with a customized whatamacallit just for this purpose! I plan on putting it in the corner of the frame rails about 12ft back... i'm bad with woodworking so you say frame in the a/c hole on the inside b4 i re attach insulate and cover?

[JohnEd]

I think they are talking about a cut off grinder  The little guy with the 1/16 Th inch wide wheel.

Harbor Freight sells a pneumatic hand sheet metal shear.  Pistol grip and all.  Cheaply and goodly executed.  It will cut through that amt of sheet metal in about less than a minute and leave a bur free edge.  Won't do any thick framing. The Cutoff handles that so you need a cutoff no matter how you do it.  A saber saw with a metal blade will do nicely although slowly and noisily.

The mating surface on the roof doesn't have to be perfectly straight/level/flat.  The gasket that goes between the unit and the roof is about 1.5 inch thick foam and it will seal a lot of miss contour.

I would put the hole in the center of a section away from frames.  Inside I would install a simple square made from pressure treated 2X4 on edge.  The legs that run from front to back should be as long as permitted.  The short 14 inch sections get placed between them.  Make this up out of the bus and screw and glue it together.  Use countersunk screws to fasten the wood frame to the roof.  Make sure there is wood under the holes that pass the tie down bolts to the inside.  When you put this frame in and draw the roof down to it it will make a small flat foundation that is strong and as vibration free as it can get.  Not that any roofs are quiet but one without dampening must be unbearable.  Mine are ancient and they are quiet on low cool setting only.

Good luck and keep us informed,

John more than 2 cents worth

[robertglines1]

if you have a air hammer they make a sheet metal bit for it...no sparks!looks like 3 prongs with center one dropped.cuts thru sheet like butter...will not cut thru structual!----handy tool around bus conversion does good job on stainless also..watch sparks if you use grinder----warm air rises so a roof air has a natural return of hot air to be cooled...with the basement air we must pull or push that warm air down to be cooled....

[bevans6]

On my MCI the roof is 2" thick and double skinned aluminium.  I bought some 3" long fine toothed wood cutting blades for my jig-saw.  I drilled half inch holes through for the corners, and cut both skins at once with the jig-saw.  Took about 5 minutes and made an un-godly racket, but created a nice neat hole very simply.  The MCI roof is slightly domed, and I offset the hole so I did not cut the center roof brace.  I installed wood cleats in between the skins of the roof so that when the AC unit is tightened down the roof is squashed flat to mate with the seal of the AC unit.  End result has been fine, no leaks, AC unit is very happy sitting at a bit of an angle, condensate drains off to the drip rail above the windows, AC power is fished to the unit between the skins of the roof.

Brian

[Eric]

I must admit i'm liking the air hammer AND the jigsaw idea.... so the only downfall to the whole project...I'm afraid of heights...painting the roof on the bus made me want to cry! LOL now i get to haul the a/c with me OH JOY!

[Greg Roberts]

I installed three of these down the center line of the bus. I welded in a 2 X 2 X 1/4" angle iron frame and then I installed a wooden frame of the proper depth inside the angle frame. Note that one portion of the angle is hanging down and the other portion is on the outside of the frame. This allows the wooden frame to slide in right up to the roof skin. After securing the wooden frame I then drilled a pilot hole and slipped a sawzall in and cut the 14X14 hole. Use what ever size wood frame you need to get the proper depth. I have an insulated drop ceiling with ducted air so mine is something around 6"-7" in depth.

[bevans6]

I got mine on the roof by putting  my ladder against the side of the bus and pulling it up with a strap.  I took off all the cardboard box except the bottom so it had the cardboard to rest against the ladder.  Easy enough, but they are heavy and awkward to move around.  Two guys would have been better than one, but I like to do things on my own.

Brian

[belfert]

I know a guy who has a forklift at home so he lifted the A/C units up with the forklift and we then carried them over to the precut holes.

[JohnEd]

Use a lift of some sort......unless you are young and STUDLY.

John