Is insulation worth it with stock bus windows?

[slaughridge85]

Just gonna put this out there. I put in 4" of insulation on my floor and 3.5" on walls and ceilings. On a 105 degree day in full sun my 10,000 btu window air unit pulls the interior down to 76 degrees... That being said, I think re-doing the insulation is very critical for climatic comfort...

[cadillackid]

Originally Posted by slaughridge85

Just gonna put this out there. I put in 4" of insulation on my floor and 3.5" on walls and ceilings. On a 105 degree day in full sun my 10,000 btu window air unit pulls the interior down to 76 degrees... That being said, I think re-doing the insulation is very critical for climatic comfort...

im guessing you also have very few windows?

insted of insulate you can install a bigger climate control unit...

A/C is for cooling and comfort.. only health concerns with A/C units are improperly maintained and improperly sized units that can spew or create mold and mildew, create condensation when it shouldnt..

im nearly 48 years old, have had A/C in every place ive lived and every vehicle ive owned.. (or i added it!) ... im not dead yet.

-Christopher

[International]

I used the board insulation left over from my house. Curtains on windows, when there not open and it heats and cools much easier. Now while driving we can hear each other talk. lol It was well worth it.

[Crozz]

I didnt see a response about the white insulation paint. We used Ames Maximum stretch paint on our roof. When its 95 outside and everything you touch is scorching to the touch, my roof is actually cool to the touch and stays that way. The inside of our bus is always cooler inside than outside and we're still building. The ames product is rubberish and doesnt transfer heat. The sides of my bus do transfer heat inside so we are definately going to line the sides with r5 insulation.

Like others we are going with a wood stove inside for when its cold and if we decide we need cooling plan to use a inside ac unit as those are rated for a larger area than my bus. Another skoolie guy who lives nearby had a porch attached above and that dropped his temp down for when he is at Burning Man.

Anyhow just my observation.

[cadillackid]

a canopy even a tent above the bus will definitely drop the temperature.. its nearly the equivalent of a cloudy day or parking your bus in the shade..

seems it would be fairly easy to make something you could set up when parked on bright sunny days and then take down if the weather got stormy or cool enough that you wanted the sun's heat..

-Christopher

[family wagon]

Something I haven't seen mentioned yet is thermal mass. That meditation space, heavily insulated and just big enough to comfortably get inside, may get very toasty very fast depending on the thermal mass present on the interior side of the insulation. If the enclosure was built of just foam board then the only thermal masses on the interior are the air contained in the space and the body of the person. A few tens of cubic feet of air doesn't have much mass. If we suppose the air was a cool 68 F degrees when a 150 pound person at 98 F gets into that space, the air's temperature will rise fairly quickly (heat from the person warms the air). It should behave much like an insulated lunch sack or Thermos bottle.

If there were something else thermally massive also in that space (brick, concrete, water, metal) then it would take much longer for the warm-bodied human to cause the air temperature to rise. The human would still heat the air but the heat would then move from the air into the thermal mass. If it's a massive mass, it'll take a lot of heat to change its temperature and the space will feel cooler much longer.

This is (in part) why it stays cool under that railroad bridge/tunnel even on a hot day. The heat source is the sun, but it shines on a relatively small portion of the structure which has immense thermal mass. The temperature of the structure and the air near it (at least on the shaded side) will probably stay near the 24-hour average temperature. If the climate were 100F days and 70F nights, the temperature there on the shaded side might tend to stay in the low- to mid-80F with little variation day or night because of the thermal mass.

We don't usually have much thermal mass inside a bus, and that's why a little bit of heat from the sun goes such a long way in making the bus hot inside (the wintertime popsicle effect is similar). Instead of adding thermal mass we insulate as much as we can (or care to) and use active heating and cooling to make up the difference.