Insulation

[Jbuck]

Bought a used hot tub at public auction last Sat. didn't know anything about tubs (still don't) but pulled the side panel off to check things out and it appears there is a thin, 1 to 1 1/2 inch thick coating of some type of spray on insulation on the tub. I am wondering if more could be added also if it is possible to insulate one to the point that the pump and other components behind the wood part get too hot. I have read enough to know this is not a high end tub, it's a Blue Ridge by Jacuzzy and marketed by Lowe's so I am sure they didn't insulate it any more than necessary when built.

[hrustar]

Bought a used hot tub at public auction last Sat. didn't know anything about tubs (still don't) but pulled the side panel off to check things out and it appears there is a thin, 1 to 1 1/2 inch thick coating of some type of spray on insulation on the tub. I am wondering if more could be added also if it is possible to insulate one to the point that the pump and other components behind the wood part get too hot. I have read enough to know this is not a high end tub, it's a Blue Ridge by Jacuzzy and marketed by Lowe's so I am sure they didn't insulate it any more than necessary when built.

Ideally, you'd like to fill the entire cavity (except the pump area) with foam spray. Many spas come with full foam insulation now. As for the pumps overheating, i've read different things about it, and not sure what is right. I'll I know is my sap has full spray foam insulation everywhere except the pump compartment, and has no issues.

[ps558]

Bought a used hot tub at public auction last Sat. didn't know anything about tubs (still don't) but pulled the side panel off to check things out and it appears there is a thin, 1 to 1 1/2 inch thick coating of some type of spray on insulation on the tub. I am wondering if more could be added also if it is possible to insulate one to the point that the pump and other components behind the wood part get too hot. I have read enough to know this is not a high end tub, it's a Blue Ridge by Jacuzzy and marketed by Lowe's so I am sure they didn't insulate it any more than necessary when built.

Ideally, you'd like to fill the entire cavity (except the pump area) with foam spray. Many spas come with full foam insulation now. As for the pumps overheating, i've read different things about it, and not sure what is right. I'll I know is my sap has full spray foam insulation everywhere except the pump compartment, and has no issues.

You could add more insulation around the pipes. The warm water in the pipes is going to try to warm the open space. Most full foam spas are filled with open cell foam which has a very low R value and soaks up water if it leaks. The easy way of adding is using rigid foam were the thin stuff was just inside the cabinet walls and adding regular rolled insulation around the base of the spa I think most of these has a open floor design you could also cut the rigid stuff to fit in between the base frame and then use the spray foam just to fill in the cracks.

Most pumps are rated at 105 c degree that is 220 degree f they will be ok. Not very much heat loss are transfer in through the shell but you will lose more from the exposes pipes. Also a good cover with at least 2 pound foam core will help alot

[Dr. Spa]

Most full foam spas are filled with open cell foam which has a very low R value and soaks up water if it leaks.

?????????? Most full foam spas use Sprayed Polyurethane Foam which is closed cell and has an R value of about R-6.88 per inch of thickness. This is more insulation value than either expanded or extruded polystyrene ("rigid foam").

[spatech (the unreal one)]

Most full foam spas are filled with open cell foam which has a very low R value and soaks up water if it leaks.

?????????? Most full foam spas use Sprayed Polyurethane Foam which is closed cell and has an R value of about R-6.88 per inch of thickness. This is more insulation value than either expanded or extruded polystyrene ("rigid foam").

You beat me to it; that was a softball.

[ps558]

Most full foam spas are filled with open cell foam which has a very low R value and soaks up water if it leaks.

?????????? Most full foam spas use Sprayed Polyurethane Foam which is closed cell and has an R value of about R-6.88 per inch of thickness. This is more insulation value than either expanded or extruded polystyrene ("rigid foam").

You beat me to it; that was a softball.

The soft foam that Watkins, sundance, D1 use that can easily removed by hand and retains water like a sponge is a open cell type foam it used more for sound deadening than insulation. Closed cell foam has a higher insulation value and water proof. if they would enclose the entire cabinet with the rigid stuff parts would break off. Why do think cold water comes out of the jets when the pump is first turned on after sitting. The heat from the water in the pipe tried to heat its surrounding which is a open cell foam and it cooled the water because something warm will try to heat anything cooler around it.

I know you still won't believe but here it is from sprayfoam.com. Its the same stuff used in spas

Closed Cell vs. Open Cell Foam

What is the Difference between Open-cell and Closed-cell Polyurethane Foams?

This may be one of the most important pages on the website if your interest is in spray foam insulation. When it comes time to actually put the foam product in your home or commercial building structure, you must identify whether you will use 0.5 lb./cu. ft., open cell foam, or 2.0 lb./cu. ft. closed cell foam. This makes a big difference in cost, application methods, and performance.

With the open-cell vs. closed-cell issue, there are two major factors to understand and consider. The first is the nature of the foam. It is either open-cell foam, where the tiny cells of the foam are not completely closed. They are broken and air fills all of the “open” space inside the material. This makes the foam weaker or softer feeling than closed-cell foam.

Closed-cell foam differs in that all of its tiny foam cells are closed and packed together. They are filled with a gas that helps the foam rise and expand and become a greater insulator. These cells can be formulated to obtain many characteristics, the most common being size and density.

Density is measured by weighing one solid cubic foot of foam material. Open cell foams typically weigh in at 0.4 to 0.5 lb./cu. ft. Closed cell foam for insulation applications range in density from 1.7 lb./cu. ft. to 2.0 lb./cu. ft. Roofing applications typically use a 2.8 to 3.0+ lb./cu. ft. to support traffic and loads better. The higher the density the foam, the heavier, or stronger it becomes. Some polyurethane foams are molded into decorative interior molding and painted or stained for a simulated wood effect. These “higher density” foams are typically in the 30 lb./cu. ft. to 40 lb./cu. ft. density range.

The advantages of closed-cell foam compared to open-cell foam include its strength, higher R-value, and its greater resistance to the leakage of air or water vapor. The disadvantage of the closed-cell foam is that it is denser, requires more material, and therefore, is more expensive. Even though it has a better R-value, typically the cost per R is still higher than open-cell foam. The choice of foam can also be based on the requirements for the other performance or application specific characteristics such as strength, vapor control, available space, etc. Open-cell SPF has an R-value around 3.5 per inch and typically uses water as the blowing agent. Closed-cell SPF has an R-value of around 6.0 per inch (aged R-value) and uses high R-value blowing agents.

Both types of foam are commonly used in most building applications and the choice for which to use can depend on many of the factors discussed above. Some foams are inappropriate in specific applications. For example, you typically would not use open-cell foam below grade or in flotation applications where it could absorb water; this would negate its thermal performance because water is a poor insulator compared to air. Closed-cell foam would be a good choice where small framing sizes need the greatest R-value per inch possible. Closed-cell foam would be used for roofing applications.

Always contact your material supplier for performance and application data on their specific materials. What type of foam being used in your building or home is always a good issue to discuss with your spray foam contractor up front, before the job starts.

[hrustar]

The soft foam that Watkins, sundance, D1 use that can easily removed by hand and retains water like a sponge is a open cell type foam it used more for sound deadening than insulation. Closed cell foam has a higher insulation value and water proof. if they would enclose the entire cabinet with the rigid stuff parts would break off. Why do think cold water comes out of the jets when the pump is first turned on after sitting. The heat from the water in the pipe tried to heat its surrounding which is a open cell foam and it cooled the water because something warm will try to heat anything cooler around it.

I know you still won't believe but here it is from sprayfoam.com. Its the same stuff used in spas

I don't know about Watkins, but my Spa has full, closed cell sprayed foam insulation. It does not absorb water, nor is my water cold when I turn on the jets. Further, as for parts breaking off, this makes zero sense. Since how could something that is held securely in place by dense foam be more likely to break off than unprotected lose pieces that can vibrate and shake.

Insulate however you like, but the only real down side to full foam that I could agree to is the hassle involved in repairing a leak should it ever occur.