I bought a used hot tub and currently its standing up on its end with the underside exposed. I'm getting some spray foam insulation done to my house and thought it would be a good idea to add some extra foam to my tub at the same time, for better insulation, at least in my mind. The way it is now, some of the pipes are still visible near where the factory foam insulation begins. It already seems to have plenty of foam in it. But I was wondering, since I live in a very cold climate with sub zero temperatures all winter, would adding extra foam insulation to the bottom actually be bad for it, since you want a bit of heat inside that area that comes from the tub to keep some of those pipes warm, as well as the pumps? The extra insulation would be good for keeping the water in the tub warm, but do you want some of its heat inside that area so that nothing freezes? The previous owners had added some extra canned spray foam that I removed since I was going to replace it with better closed cell spray foam, like whats already in there.
