real time temperature tests with insulations

[gulfyankee]

I'm experimenting with insulations for my bus. As I speak, it is 99 degrees ambient outside, 85 inside the bus, with a 15000 btu coleman roof air running. No shade, I removed a roughly 2' x 3' section of my ceiling and the old fiberglass insulation last night. In its place I have placed a layer of reflectix, and 2 layers of 3/4" blue foam board. Temperature readings are as follows.

Outer roof skin, 135 degrees
Reflectix only, 115 degrees
Reflectix, one layer of foam board 97 degrees
Reflectix, two layers of foam board 93 degrees

In comparison, the neighboring ceiling is measuring at 100-120 degrees

Pretty amazing that the reflectix alone was able to reduce the temps 20 degrees!

[robertglines1]

are you using the white bead foam board or the ble/pink foam insul board?

[usbusin]

2 layers of 3/4" blue foam board

[gulfyankee]

Blue

[robertglines1]

sorry : I re-read it and saw what my mind missed the first time!       Like good results. I have a total of 4 inches of foam on my roof in my new build and 3 inches on side walls.

[robertglines1]

Want to thank you for posting: sometimes we need to be reminded that insulation is key to comfort in our coaches summer and winter. Actual test results lets members decide where to invest their available $ to best use.   Bob

[gulfyankee]

Well whats in here now is 3" thick fiberglass batting stuffed into a 2" space on the ceiling, and ceiling tile stuffed into the walls. Unacceptable. Going to experiment with more layers of the reflectix. Shooting for 2" of insulation all around. Trying to preserve headroom.

[robertglines1]

Scott; I had room for extra on ceiling with the xle ceiling height (like a foot roof raise). Sounds like you work construction? I did for years;didn't have to travel much.  Good luck and be assured your insulation ideas are rite on. as much bang for the $ as you can get in the space available. Make sure all metal has at least a thermal break covering on it. Metal acts just like a toaster coil. I'm sure you knew that though.  Bob

[gulfyankee]

Same conditions as yesterday- this time with alternating layers of reflectix and foam. From outside in, RFRF. Same temps everywhere else, temps at new insulation running mid 80's. Think this its the combo I am going to use. Total thickness, 2".

[gulfyankee]

Robert- yes I work construction as a pipefitter. I travel because I like to, I enjoy seeing new places, and make more money doing it. I'm going to be working a local job for awhile, so I'm hopeful to be able to actually get some progress made when the weather cools off. I have a camper out on my property, so I am thinking w are going to move back into it for a little while and just gut this thing and reinsulate, then at least get the walls done and the basics back in before we go somewhere else again.

[Mex-Busnut]

I am certainly no expert, but I want to add my two pesos' worth of info.

The hardware store guy recommended I try this Sika® paint, which, he says, some of his customers are using on the inside walls and ceilings of refrigerated semi trailers. The paint is acrylic, and is said to have excellent water-proofing and thermal properties. It is supposed to work well with moving joints, as it is elastic. And it is said to reduce (according to the hardware store guy) the temperature up to 8 degrees Celsius ( 46.4 degrees Fahrenheit).

We put four coats of this stuff on our bus's ceiling. My experience: When the sun is hot enough to make the roof untouchable, the ceiling feels quite cool on the inside. (Maybe a few more coats and ice cubes will begin forming.)

 

Under this, we are using the pink foam board, as per recommendations from several on this great forum. This only has an R-rating of 5.0, so maybe we will run double foam.