Hot Tub Insulation

[TresK3]

I just got done fixing the leaks on my Jacuzzi outdoor spa. This involved taking off all the skirting and removing the foam insulation. It turned out that a number of mice had carved nests into the foam. I cleaned those voids and sprayed in some expanding foam insulation. As I'm putting back the insulation, I'm noticing lots of areas where I could fit additional insulation. My first thought was Styrofoam panels, cut and wedged in. Then I got to thinking about fiberglass batting... it would be easy to push into the spaces between the the existing foam and the shell of the hot tub.

Anyone have experience with this? My main concern is moisture; as long as it doesn't leak again, it *should* stay dry. What happens if this stuff gets a little wet? A lot wet? Any other ideas or thoughts on how to insulate this space?

TIA,
Tres

 

[fdegree]

Why not spray some more of the expanding foam in those area?

For more professional in put, you may want to try this forum...
What's The Best Hot Tub

 

[gpcollen1]

1 - Make sure the tub and the pipes have a good coating of foam on them.

2 - Don't use fiberglass. When it gets wet it is useless...

3 - Tip that tub up on its side and insulate the bottom. I am putting in 2 inch solid foam insulation. This will make it as energy tight as a new and expensive tub. When I ask why all tubs don't come this way - the answer is silence. Then spray foam the space on the bottom between the bottom framing and the skirt. This will keep future mice out of there.

 

[Highbeam]

The reason not to get carried away here is that those 5 HP motors need air circulation to stay cool. You will burn up your pumps if you reduce this airflow.

 

[gpcollen1]

The reason not to get carried away here is that those 5 HP motors need air circulation to stay cool. You will burn up your pumps if you reduce this airflow.

The brand new expensive tubs come insulated as heck. What I recommended would be equivalent to them. The newer pumps also extract heat from the motor. This airflow issue is not an issue with any newer tubs for sure [5-7 yrs old or newer for sure]. Just looked at my buddy's new tub - insulated as you can possibly get. He is a Pool and Spa tech. He says insulate the bottom as much as you can and don't forget the bottom frame to the skirt with spray foam. Screw air circulation.

 

[Highbeam]

The OP's machine is a Jacuzzi, an older spa. Further, my tub is newer than 5-7 years and there is plenty of room left for air circulation to cool the motors. Even vents through the skirting to the outside.

I call BS on your idea that the motor dumps heat into the wet end of the pump. Have you ever even seen a hot tub pump? It's a big motor attached with a shaft to a pump head. The pump head has water in it, no cooling water for the motor. The motor has air vents and a fan to pump air through the AIR COOLED motor. Don't be a fool and eliminate this air supply. Are you saying that these ultra modern tubs use water cooled motors? I'd love to see it.