Since I used inflexible panels, bolting them to the roof—and the hole for the cords to go inside—also required drilling into the van’s roof, so for the same reasons as the fan and window project, it needed to happen before anything else. Almost. Order of operations is important.
Solar panels create heat, which transfers to the van metal and can heat up the inside of the van unpleasantly on hot summer days, especially if I want to park out of the shade to use said solar panels. So before installing them I painted the entire roof in two coats of a heat refracting paint.
Finding such a paint turned out to be quite an undertaking. I was looking for paint that would refract solar radiation—heat—and there are quite a few on the market specifically claiming to lower your home energy costs by painting the roof with their specially formulated white paint. There is a lot of controversy around these types of paints, and many on the market are clearly scams, while some seem to have some value to them.
Telling them apart, however, was a challenge. Marketing is often good even for snake oil products, reviews are often mixed, or customers can’t tell for sure if it was the paint that made the difference or simply painting their roof white, which itself refracts sunlight. Youtube videos demonstrating the products’ wonders are often impressive, but easy to doctor or mislead. One leading brand claims to be endorsed by NASA, but as far as I can tell, it merely made it into a NASA bulletin once about up and coming technologies. That is not the same as an endorsement.
After extensive research, I sided with the recommendations of the Cool Roof Rating Council report that rated the effectiveness of a few hundred of these types of paints. One of the leaders was Liquid Rubber Cool Foot Coating for decks and docks. This looked like the least environmentally nasty among the few that, according to the report, had statistically significant results over just white paint.
So I decided that the potential gains were worth the risk of loss if it turned out to be a dud, and ordered two gallons. These were painted on in three thick layers and left to set for a day between each coat.
I painted just the roof, from gutter to gutter widthwise, and forward to about where the front of the cab windows would line up if extended vertically, so from the ground it isn’t even visible. Which is good because, though the van was already white, the paint is startling, eye-hurtingly white—I had to wear sunglasses when installing the solar panels to be able to look at where I was drilling.
As of writing this, it has been about ten months since I painted it on, and I am happy with it so far. The roof has been obviously cooler to the touch than the unpainted metal next to it, even on hot days. I am not entirely sure whether that has actually translated into a cooler van, but I did live in the van in the summer in New Mexico and had very few issues with heat, even on hot days. It wasn’t one of the hotter summers I’ve experienced there, but it still got pretty uncomfortable at times. I’m suspending judgment for now, but it seems promising.
With the paint dried, I could install the solar panels:
The placement of ribbing in the van’s roof determined where I could put the fan, and the fan placement largely determined where the solar panels went. I didn’t want to just stick them in the middle of the roof, I wanted to maximize potential places for more solar panels in case I decide later on that I want more.
Drilling holes for the panels.
Sorry there aren’t more pictures, these were also lost.
Can you tell the difference in shades of white between the edges of the roof and the painted middle portion?
All finished! Yay, no more cutting up the van!