What helps with thermal transfer or heat from the sun?

[nolahusker]

I measured the temperature differential between ceiling and floor in my bus last winter and found it to be about 5 to 6°F (and this was without any kind of fan circulating the air inside). This isn't nothing, but it doesn't lead to any kind of enormous difference between the amount of heat transferred through the ceiling and the amount transferred through the floor. I mention this because it's common for skooliers to think that only the ceiling needs insulation (there's another camp that thinks heat loss is mainly through the floor, which is also incorrect - all surfaces need insulation).

Insulation for heating is a different animal, for sure. If you’re worried about cooling only, the ceiling is most important, by far, because it receives radiation. In heating season, there is radiation loss on a clear night, for sure (the sky temp is outer space - pretty cold for radiation loss), but the difference in heat loss in heating it isn’t as dramatic as the difference in heat gain between ceiling and floor in cooling season. If I picked only one surface to insulate, it would be the ceiling, but you are correct in stating that all surfaces need insulation.

 

[Meathead]

I deleted some windows but I was adamant about keeping my bus windows. Even with the deletes, my bus looks like a bus.

Prolly the best thing I developed for my bus is my insulated window slides.
Two years now and it works great.

I took 1/2” insulation board and glued Formica onto both sides to form a Formica sandwich.



I did some whole windows also.

For those extra hot/cold days I can slip in an extra piece of insulation.


I had to work out some sliding issues and staying in place issues but the insulation and reflectivity of the Formica always worked. For example once I realized that the slides were usually all the way up or all the way down, I installed magnets at the top to hold them up. The handles are sheet metal bent to shape.

[emoji3522]Dave

 

[kidharris]

It is a nice looking finish, but not sure that I understand. Do the panels drop down into the wall? Is there a second panel/layer to insulate the bottom when the panel is pulled up? Do you have anny pics of wall construction?

 

[nolahusker]

That’s an interesting idea.

 

[AmberVinny203]

So what types of materials is anyone having success with as far as insulating the ceiling? How about spray foam? Can anyone say for sure if it really works or are they just going to say it works because they spent $2000-$2500 to have it installed? I do certainly understand about the thermal transfer science and using things like butal tape and very little contact with the metal as possible etc. I see some of these people spend the big money on foam and then fail at their framing which really defeats the purpose almost of spending the big money to do it right. In short, just wanting to know if the spray foam is worth it? I mean, if I can use a different product that's half the cost, and spray foam is only marginally better, then I'll save my money. If it's night and day difference and works twice as well as other products that are half the cost, then I can see spending the money if that makes sense.

It helps but honestly it’s not life saving. We spent 1000 on the ceiling being done professionally

 

[Meathead]

It is a nice looking finish, but not sure that I understand. Do the panels drop down into the wall? Is there a second panel/layer to insulate the bottom when the panel is pulled up? Do you have anny pics of wall construction?

I don’t have a lot of pics. Haha that’s why I don’t have a built thread!

Anyway. I found pics of early iterations. There was a lot of trial and error.

Pic 1. Covering window bottoms w aluminum. Not against the window. Screwed to the back of the hat channel leaving an air gap.


This one shows the slide channel. There is room for 1” poly iso between the channel and the aluminum.
View attachment 1

Also most of the Formica sandwichs are the full length of the window so they cover the bottom half also. (in closed position.

This is a Thomas. The windows angle in at the bottom of the window

[emoji3522]Dave

 

[Meathead]

Ok. I don’t know how that extra battery pic got in there….and I can’t fix it [emoji50]


More window pics:







[emoji3522]

 

[HamSkoolie]

INSULATE and SHADE
We're still building but our plan includes spray foam on ceiling and walls with foam board under the floor.
We're covering almost the entire roof with solar panels (10 of them) with a small walkway down the center and 4-6" above the roof at centerline (more at the edges) to create an air gap and flow below the panels to (1) allow panels to stay cooler and (2) keep direct sunlight from hitting the roof. The walkway will also be covered with wood 2x4 or 2x6 to keep shade there as well. It will also minimize UV and heat damage to the roof paint thus reducing the heat load on the roof.
We will be carrying our "shade" with us wherever we go as we want to be able to park in the sun and collect all that solar to charge up our 10kWh (expandable to 20kWh) battery bank of EG4 rack mount batteries.

Spray foam has multiple benefits.
1) Insulation of about 7.5 per inch
2) SEALS air and water intrusion
3) "locks" everything together
4) Sound deadening
We're also installing a 12K mini split in the front over the windshield and a 9k mini split in the rear bedroom. Either should be able to keep an insulated bus cool or warm but getting air from the front to the rear is expected to be an issue so the 9k will cool the bedroom on hot nights while the 12k in the front should keep the main areas cool on even the hottest days.

 

[nolahusker]

Note that R-7.5 for spray foam is unlikely to be achieved. The absolute best installation will be R7 per inch. I’d count on R-5 to R-6 per inch.

 

[HamSkoolie]

Note that R-7.5 for spray foam is unlikely to be achieved. The absolute best installation will be R7 per inch. I’d count on R-5 to R-6 per inch.

Even at R-5 our side walls with have R-15 or so and the ceiling R 7.5 plus.



And our roof with have almost zero direct sunlight hitting the original roof as the panels provide permanent shade and an air gap to minimize heat penetration.


As for using wool, it's organic and I wouldn't use anything organic for insulation as it can become a feeding ground for vermin, mold, and other life forms.

 

[nolahusker]

Even at R-5 our side walls with have R-15 or so and the ceiling R 7.5 plus.



And our roof with have almost zero direct sunlight hitting the original roof as the panels provide permanent shade and an air gap to minimize heat penetration.


As for using wool, it's organic and I wouldn't use anything organic for insulation as it can become a feeding ground for vermin, mold, and other life forms.

I’m a former air conditioning designer turned forensic engineer diagnosing failed air conditioning and I approve this message.

 

[Sterios]

Hello everyone. I'm wondering if anyone has ever just framed in an entire box and insulated and wired that just like you would a room in a house? Floors, ceiling and walls! Just wondering thanks