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Hot tub insulation review (Good, better, best)

Thinking of buying a hot tub and asking yourself ‘how to insulate a hot tub?’ or ‘what is the best insulation for my hot tub’. The better the insulation, the warmer the water stays, the less power you use and the lower your power bill.

In this article you will learn about the significance hot tub insulation can have on reducing running costs and the most effective options to keep in mind from good, better to best.

The J-200™ Collection

Challenges of no hot tub insulation and running costs

Less insulation & lower quality materials leads to -

-Less heat retention

-Greater amount of heat lost 

-More energy used to maintain heat 


Benefits of hot tub insulation and running costs

More insulation and higher quality materials leads to -

-More heat retention

-Less heat lost

-Less energy used to maintain heat - better energy efficiency


The J-200™ Collection at a glance

No hot tub insulation - Quick review

That’s right, some hot tubs aren’t fitted with any insulation. You can make your own mind up about that to be honest!

Yes the hot tub may have a cheaper price tag, but it won’t come out on top when it comes to lowest running costs.

Thermal wrap hot tub insulation (traditional material insulation)

Mineral Wool insulation- quick review

Most mineral wool options do not have additives to make it fire resistant, making it poor for use in situations where extreme heat is present.

Fibreglass insulation - quick review

A great value product. The high weave of fine strands of glass into an insulation material minimises heat transfer. It is an excellent non-flammable insulation material.

J-300™ Collection

Polystyrene insulation - quick review

A rigid insulator, unlike its fluffier cousins. Typically the foam is created or cut into blocks.

Cellulose insulation - quick review

In a nutshell: A very eco-friendly form of insulation and it is also one of the most fire resistant forms of insulation.

Thermal wrap review

To consider: All these insulation types are positioned next to the parts of a hot tub and can leave voids. Anywhere air can gather, means it can cool. You want your insulation to eliminate as many voids as possible.

For example, think of the underneath of the shell. The curves and angles are not really compatible with flat sheets of insulation, no matter how pliable. So, you get voids.

You may find some hot tubs use thermal wrap as well as shallow foam insulation.

J-300™ Collection at a glance

Partial foam insulation in hot tubs - Quick review

Spray Polyurethane Foam (SPF) delivers a very effective form of protection because it is sprayed directly onto every internal part of the hot tub.

As you have already read, the aim is to eliminate the voids between the unit parts and the insulation. By spraying the foam directly onto the interior parts of the hot tub, it creates ‘permanent contact’. This reduces the initial air gaps that forms between components and material insulation.

Other benefits include:

· The foam sets hard adding a protective layer as well as insulation.

· It’s waterproof.

· Thinner layers of insulation, yet more effective coverage.

· Covers difficult to reach areas.

· Begins to deliver sound insulation.

The key to the foam working more effectively than traditional material insulation is down to air bubbles within the polyurethane. These air bubbles help to create the honeycomb effect so vital in retaining warmth and not letting it escape.

Hot tubs with full foam insulation - quick review

Hot tubs with full foam insulation - Quick review

Full foam insulation is maybe the easiest option to talk about and probably the most effective.

Full foam insulation fills three sides of the hot tub, leaving the equipment area non-filled so it’s accessible. You will actually find full foam insulation on Jacuzzi® Hot Tubs.

By filling every void - but leaving a gap so the control panel can be accessed, you remove the places for heat to escape. In addition, and to complement the money saved in potential heat loss. Full foam insulation also reduces any noise created from the pumps and jets too. This means you can enjoy a quieter soak in your hot tub. 

It's worth noting that if there’s a leak, full foam insulation can restrict access and make it more challenging to find the leak. This may put your hot tub out of action for longer than a material insulated hot tub. However, leaks from a quality-build hot tub should be rare. 

What hot tub insulation is best?

Whichever kind of insulation you choose, you must remember to check where it touches and fills. Ideally you want it to -

· Wrap completely under the shell.

· Cover the base.

· Fit fully against the cabinet sides.

· Fill as many of the voids within the unit as possible

What hot tub insulation is best?

We often get asked ‘What is the best hot tub insulation?’ To be honest, the answers vary across make, model and location. In this instance we want to help you make your own mind up with an easy to follow rating system - Good, Better, Best.

Good - Thermal wraps. Easy to access and locate any problems with this insulation type. Works well as a heat reflector back towards the hot tub. 

Better - Partial foam. Good for heat retention due to the shell being sprayed with foam. 

Best - Full foam. Fills most areas except the equipment zone. The only downfall, finding a leak can be more challenging but it’s still possible to solve. 

Hot tub frame review (Good, better, best)


After reading this article, you should now be able to scroll on a product page or visit a showroom with more clarity and awareness on what type of insulation is most effective at retaining the heat in your hot tub.

From listing what we recommend as the good, better and best options, you have the learning tools you need to find out if the insulation in your preferred product will help you save money on energy costs over the life of your hot tub.

Remember - the better the insulation, the better heat retention and the better the savings on energy.

hot tub

Interested in learning more about the insulation you’ll find in Jacuzzi® Hot Tubs and finding a dealer close to you?

Click the link below to find your nearest showroom where you can speak to our friendly sales team.

Find my Jacuzzi® Hot Tub dealer