insulate--insulate--seal--

[robertglines1]

Is the time of year busnuts visit the subject of Air Conditioners.  My last build#4. I decided to use the harbor freight  temp checker.  On a prevost of my vintage they have spray foam between ceiling joist ,side girts,and bottom of bay floors (from bottom). I shot the ceiling temp first on exposed insulation surface About 80 deg =same as outside temp. I took a reading on ceiling joist/metal frame work 140 deg.  rechecked--sitting in sun white roof.  Wow --just like a toaster element..Sides presented simular result but not as dramatic.  Solution: need a thermal brake to keep steel structure from acting like a toaster transferring heat inside.  Added 1inch foil backed insulation board to ceiling and sides. Then layer of luan to attach ceiling and side material to. Later after thought I also added a layer of insulation (1 inch blue board to ceiling of bay.  Sealed any gap with foam in a can  to make sure to insure thermal brake.  The amount of heat or AC you need is determined to a large extent by how much heat /cold transfer you have. So plan ahead if you are just starting or if you are redoing your project..  I make lots of mistakes every day!! I hope I /we learn from them.  Bob  brake or break?=heat cold transfer

[luvrbus]

Is the time of year busnuts visit the subject of Air Conditioners.  My last build#4. I decided to use the harbor freight  temp checker.  On a prevost of my vintage they have spray foam between ceiling joist ,side girts,and bottom of bay floors (from bottom). I shot the ceiling temp first on exposed insulation surface About 80 deg =same as outside temp. I took a reading on ceiling joist/metal frame work 140 deg.  rechecked--sitting in sun white roof.  Wow --just like a toaster element..Sides presented simular result but not as dramatic.  Solution: need a thermal brake to keep steel structure from acting like a toaster transferring heat inside.  Added 1inch foil backed insulation board to ceiling and sides. Then layer of luan to attach ceiling and side material to. Later after thought I also added a layer of insulation (1 inch blue board to ceiling of bay.  Sealed any gap with foam in a can  to make sure to insure thermal brake.  The amount of heat or AC you need is determined to a large extent by how much heat /cold transfer you have. So plan ahead if you are just starting or if you are redoing your project..  I make lots of mistakes every day!! I hope I /we learn from them.  Bob  brake or break?=heat cold transfer

Is the time of year busnuts visit the subject of Air Conditioners.  My last build#4. I decided to use the harbor freight  temp checker.  On a prevost of my vintage they have spray foam between ceiling joist ,side girts,and bottom of bay floors (from bottom). I shot the ceiling temp first on exposed insulation surface About 80 deg =same as outside temp. I took a reading on ceiling joist/metal frame work 140 deg.  rechecked--sitting in sun white roof.  Wow --just like a toaster element..Sides presented simular result but not as dramatic.  Solution: need a thermal brake to keep steel structure from acting like a toaster transferring heat inside.  Added 1inch foil backed insulation board to ceiling and sides. Then layer of luan to attach ceiling and side material to. Later after thought I also added a layer of insulation (1 inch blue board to ceiling of bay.  Sealed any gap with foam in a can  to make sure to insure thermal brake.  The amount of heat or AC you need is determined to a large extent by how much heat /cold transfer you have. So plan ahead if you are just starting or if you are redoing your project..  I make lots of mistakes every day!! I hope I /we learn from them.  Bob  brake or break?=heat cold transfer

The best advice one can give spend the money ,and glass is one of your greatest for cold and heat tranfer,the double pane glass is not cheap but worth every dime

[sledhead]

nice job Bob
very similar to what I did to the mci but I installed 3/8" x 2" wide ply to all side ribs and on the ceiling I strapped the inside 1.5" down and then had the coach spray foamed flush to the ply strapping then installed 3/8" ply to all of interior walls and ceiling . It made a huge difference for both cooling and heating the coach

dave

[benherman1]

Anyone have any recommendations for insulating over those ceiling beams while keeping as thin as possible? I have a 5A and I'm 6'3" so there isn't a lot of wiggle room. The current plan is to do one of the thick silicone coatings on the roof which should keep the temperatures down then insulate between the beams. I wasn't planning on insulating over them but it sounds like it might be necessary.

One Idea I've had is that I plan to do a solar setup at some point and can create some ribbing to elevate the panels an inch up from the roof or so. Doing this should create the "double roof" effect they used on the Saudi buses.

I'm also hoping to keep the floor as this as possible which likely means little or no insulation there. Not sure what options I have on that front yet.

[DoubleEagle]

Try EHP rollboard on the ribs (1/8" thick), and insulate the floor from underneath where possible.

[buswarrior]

You can insulate, or you can install more BTU.

Either way gives comfort, just depends how you want to spend your ca$h.

There is no free lunch, heating or cooling.

Comfort = CA$H

Period

Happy coaching!
Buswarrior

[TomC]

I screwed 1x2 fir studs horizontally over the metal supports. Then had spray foamed that gave me 2.25" of foam. Best money spent. Consequently in 108 degree weather driving, only 2 13,500 roof top A/C's keep us comfortable inside. Good Luck, TomC

[dtcerrato]

We glued 3/8" thermal dense foam carpet padding on the entire ceiling - from top of windshield to top or rear window & from top of side windows side to side. No heat transfer at the structural ribs. Worked well

[benherman1]

Try EHP rollboard on the ribs (1/8" thick), and insulate the floor from underneath where possible.

I've done some looking and it seems like neat stuff. The only problem I have is I can't find anyone selling it. Any idea what kind of price it would be or where to go?

[DoubleEagle]

engineheatprotection.com, $2.25 a square foot. They advertise on BCM.