Best hot tub insulation

What is the best insulation for a hot tub?

The best insulation for hot tubs is full foam, multidensity foam, barrier insulation or FiberCor. When comparing energy-efficient hot tubs, look for full foam or multidensity foam. If the description doesn’t specify full foam, the tub is likely only partially insulated with spray foam.

» MORE: Most energy-efficient hot tubs

Hot tub insulation types

There are many different ways for hot tub manufacturers to insulate their tubs. Hot tub insulation foam is usually made out of urethane and sprayed inside the cabinet. Barrier insulation, thermal wraps and FiberCor are also common types of hot tub insulation.

Partial foam insulation

With partial foam insulation, spray foam only fills part of the cabinet. While it won’t add the highest levels of energy efficiency, it’s a solid option if you're primarily concerned with the cost of the hot tub. Partial foam insulation is the most common and affordable option for hot tub insulation.

Full foam insulation

Unlike partial foam, this type of foam insulation fills the entire cabinet so no air can escape. Full foam insulation also helps protect parts from movement and makes the shell more durable and stable. Full foam is more expensive than partial foam insulation, but it’s more energy-efficient and effective.

Multidensity foam insulation

Manufacturers make multidensity foam by using a variety of density levels when adding foam insulation. This variety allows the manufacturer to put the right level of insulation density where it makes the most sense, leading to the highest level of support and efficiency. However, it’s more expensive because it takes longer to install and costs more to make.

Thermal wrap insulation

This is more commonly used in swim spas than hot tubs because it doesn’t add that much insulation in the long run. Thermal wrap insulation blankets the inside or outside of your tub and help keep in some heat. Sometimes the outside wrap can be coated with reflective colors to help minimize the escaping warmth.

This insulation is better than no insulation, but it's not the best option overall. However, you can choose to add this to your tub alongside other insulation to provide added benefits. Thermal wraps can also combine with spray foam insulation.

Barrier insulation

Barrier insulation coats the inside of the spa cabinet while allowing for air to move through it. This type of insulation allows heat to transfer more effectively without the use of pumps or vents, which are needed when using foam insulation. Reflective foil barriers reflect heat while doubling the barrier for added insulation.

FiberCor insulation

This is a new type of proprietary insulation by Watkins Wellness. FiberCor is similar to full foam because it’s sprayed into the cavity. However, instead of foam, this type of insulation uses a fiber similar to wool. It is four times as dense as foam and easier to remove.

Find the best ways to insulate a hot tub

There are a few other excellent ways to add more insulation to your hot tub:

• Hot tub cover: Make sure you have the proper cover and straps to retain heat when the hot tub is not in use. Using a high-quality insulated hot tub cover is the best way to get the most bang for your buck.
• Hot tub or spa blanket: Investing in a hot tub or spa blanket helps optimize insulation because it floats on top of the water and decreases evaporation.
• Pump shroud: A pump shroud transfers heat from the hot tub components to the water, which minimizes energy consumption.
• Hot tub platform: You can reduce contact with the ground by placing your hot tub on a platform, which helps prevent heat from escaping.
• Spray-foam kit: Owners can use spray-foam kits to improve hot tub insulation, but the DIY process can be complicated.

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Ultimately, the best way to insulate a hot tub is to pay a professional. By consulting a professional, you avoid problems that are a byproduct of beginner mistakes, including mold growth and malfunctioning products.