Hot Tub Insulation Guide
One of the most important factors in determining how much a hot tub costs to run is how well it is insulated.
A home spa with good insulation may cost more up front, but once the cost of running the spa is taken into account, the increase in energy efficiency will make it cheaper over time.
So, if insulation is so important, what is the best hot tub insulation?
Here's everything hot tub owners need to know so they don't get a nasty surprise when they look at their smart meter.
Types of hot tub insulation
Not all hot tub insulation is the same. Here's a breakdown of each type of insulation found on home spas on the market, as well as our recommendations for the best hot tub insulation.
What if there is no insulation?
Some hot tubs do not include any insulation at all.
This category includes all inflatable hot tubs. As a result, they are expensive to run and and cost more to heat up before being used (especially in colder months).
One of the reasons we recommend never buying a hot tub without asking for specifics and proof that it is insulated, is that some hot tubs made in other countries come with no insulation at all between the shell and the exterior.
Unscrupulous hot tub sellers will frequently call a hot tub "insulated" because it comes with a cover filled with a thin layer of insulation. Although these spas are technically insulated, they will not retain any heat. Also do not be duped if dealers attempt to suggest that insulation is a marketing ploy!
These hot tubs are expensive to operate and take an eternity to heat up. Furthermore, the components will have to work harder, to maintain the same temperature, which will reduce their life span.
Furthermore, you can bet your bottom dollar that any hot tub manufacturer willing to sell spas without insulation, is also cutting a lot of other corners!
Thermal wrapping
Some low-cost hot tubs will be insulated with nothing more than a "thermal blanket," which is a reflective material wrapped around the shell to reflect heat back into the tub.
This type of insulation is only marginally more effective than no insulation at all and is therefore unsuitable for hot tubs. It doesn't work as well as foam insulation because it doesn't keep as much heat in.
However, thermal wraps are appropriate for swim spas' swim chambers, which do not require as high temperatures as a hot tub. As a result, this type of insulation isn't as much of a red flag when shopping for a swim spa, as it is when shopping for a hot tub.
Insulation with partial foam
Most hot tubs are partially insulated by a layer of foam insulation sprayed onto the shell. This helps a home spa keep its heat and gives it structural support, so the shell doesn't crack or warp over time.
We suggest that you don't consider any hot tubs that haven't been partially insulated with spray foam.
However, it's worth noting that partially-insulated home spas are best suited to warmer climates than the one we have here in the UK. While they are a step up from a thermal wrap, choosing a fully foamed model will save you money on your annual hot tub operating costs.
Complete foam insulation
High-quality foam is used to completely insulate the most energy-efficient home spas.
A fully insulated hot tub will obviously cost much less to operate than one that is poorly insulated. It will also be less prone to repairs because the insulation will keep the pipes in place, reducing the likelihood of leaks. Choosing a "fully-foamed" hot tub could save you money on repair bills as well as energy costs.
The only part of the most efficient spas on the market that isn't insulated is the equipment bay, which must be ventilated and easily accessible for service. However, aside from the equipment panel, the more insulated a hot tub is—and the higher the density and quality of the insulation—the better.
The cover for the hot tub
Hot tubs lose approximately 60% of their heat through the water's surface. So, even a hot tub with the best-insulated cabinet in the world won't retain much heat if the cover isn't up to par.
Choose a hot tub with a high-density polyurethane foam cover that is at least four inches thick in the centre and tapered to the edges to allow rain to drain.
A high-quality cover folds in the centre, with a "continuous heat seal" along the underside to create an airtight seal that significantly reduces heat loss.
We also strongly advise you to purchase a hot tub with a cover that has lockable clips. These will keep the air out, keep the cover from blowing off in the wind, and keep kids from getting into your home spa when you're not around. Also using a tarpaulin or soft cover over your hot tub will protect your cover from weather deterioration and it will significantly prolong it’s durability.
How should I insulate my hot tub?
Not happy with how much your hot tub is costing you in terms of electricity or regretting purchasing a home spa without insulation after reading this guide?
If you're a gifted DIY’er, you can add insulation to your existing hot tub to prevent heat loss and make it more energy efficient.
However, we strongly advise against purchasing a home spa with inadequate insulation and attempting to insulate it yourself. The best job you can do will pale in comparison to what any half-decent hot tub manufacturer will send off the assembly line as standard.
Even if you wrap thermal blankets around your hot tub's cabinet or spray foam on its shell, it won't lower your energy bill as much as replacing a poorly insulated model with one that is fully foamed.
Furthermore, adding any type of insulation to your hot tub on your own is likely to void its warranty, leaving you out of pocket if something goes wrong.
Conclusion
We strongly suggest that you only buy a hot tub that is fully insulated.
And if your budget allows for a spa that has been fully insulated with multiple layers of high-density foam, we recommend you pay the extra up-front cost so you can enjoy much lower running costs over the life of your hot tub.
There are multiple factors that combine to make our spas the most energy efficient Hot Tubs on the market:
Manufactured using multiple layers of high-density foam which reduce heat loss significantly
Low current pumps consume less energy than a 75W light bulb
The inside of the Hot Tubs route warm air back into the system to reduce the energy required to heat the water
Covers which use high density foam to create a seal minimising heat loss
During circulation the water temperature is kept at a regular temperature, reducing the energy used in a standard heating/cooling cycle.
All our Hot tubs at Creative pools and Leisure are R rated and have consistently won the UK energy efficiency awards in the UK.
We hope you found this discussion on hot tub insulation informative and helpful. At Creative Pools and Leisure, we believe that insulation is a crucial aspect of hot tub ownership, and we are committed to providing our customers with the best products and services to ensure their hot tubs are as energy-efficient and comfortable as possible. If you have any questions or would like to learn more about hot tub insulation, please don't hesitate to reach out to us. Until next time, stay warm and enjoy your hot tubs!