Most swimming pool insulation material deemed suitable by manufacturers and swimming pool builders for use in pools, has never been independently tested for swimming pools. This certainly isn’t the case with Thermapool.
We’ve spent the last 8 years working with Universities in the UK, building institutes and swimming pool trade bodies to help us get a comprehensive view of how to prevent swimming pools from losing heat.
We’ll spare you the science lesson, but this is what we discovered to give Thermapool significant insulating benefits:
Heat doesn’t just escape from the top of a pool
It makes sense that heat evaporates from the tops of swimming pools. However, there are other areas that lose significant amounts of heat that are often not considered by builders due to cut backs. It doesn’t matter whether the pool is above-ground or in-ground, the sides and bottom of the pool will still lose heat into the soil.
By fitting insulation to the sides and bottom of a pool, Thermapool have discovered they can prevent an incredible 86% of heat loss from the pool.
Insulation needs to be dry to be effective
Insulation materials used in general building construction are excellent at keeping heat in because they stay dry. Unfortunately, they’re ineffective for insulating swimming pools, because they become wet and lose their insulation properties.
This discovery led us to develop Thermapool insulation which is completely waterproof and impervious to moisture. Thermapool has been independently tested to keep its thermal performance for more than 40 years so we guarantee it for 25 years ensuring its insulating properties.
Fitting insulation to the inside of the pool is more effective than fitting it to the outside
You wouldn’t think it would make much difference whether pool insulation was fitted to the inside or the outside of a pool. Well it does: a 50% efficiency difference in fact! When pool insulation is fitted on the outside of the pool, only 41% of heat loss is prevented. Thermapool’s unique waterproof qualities mean it can be fitted to the inside of the pool and prevent a significant amount of heat from escaping into the soil.
Pool insulation needs to be robust
Like a normal building, swimming pools can be affected by minor ground settlement causing them to crack. Unlike other pool insulation materials, Thermapool has been designed to withstand these minor movements as well as the incredible weight and pressures water puts on to the walls of a pool. This means it can not only be used on the sides of the pool but also on the bottom. This means it can be used to insulate the entire pool.
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Heat Loss From Swimming Pools
Professor Hassan Shirvani of Anglia Ruskin University, Cambridge is one of the country's leading specialists of heat transfer in fluids working with Rolls Royce Jet Engines and Jaguar on technical issues. He has been working with the founder of TOPIC UK Ltd, Nigel Rose.
Shirvani and Rose believe there is much more research that can be carried out on the subject of energy loss and energy gains from swimming pools which both the pool industry and customers will benefit from financially..
Whilst energy losses from the ground are relatively simple to calculate due to the steady state of the soil temperature, the benefits of solar energy gains from the sun's rays into a swimming pool "the green house/solar heating of pools" is not. In other words, how energy is gained by the water from the sun, thus heating the swimming pool for free.
If you scuba dive you will know that the deeper you dive the darker and colder the sea becomes, this is because the sun light rays are absorbed by the water. As water is transparent it allows the rays to travel through it, but as it does so it loses energy as it has moved the water molecules which generate heat.
30% of the suns energy reflects off the earth's surface and goes back into the atmosphere, a clear swimming pool absorbs 100% of this radiant energy and magnifies it, like a pencil does in a glass of water.
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Heat doesn't just rise for a pool. Heat comes from many sources.
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The human body radiates heat on the skin surface at 37 °C. Strenuous exercise can raise the body's temperature to as high as 41°C.
Municipal swimming pools operate at 27°C. Swimmers exercising, radiate heat at +14°C from their bodies into the swimming pool, thus heating the swimming pool water for free. At peak times, when there can be more than 20+ adults exercising, there is considerable energy being radiated from these swimmers into the pool.
In the same way that eco buildings have been developed to reduce energy requirements and reduce running costs, by making the most of the natural energy that exists around us, (eg. south facing windows to make the most of solar gains and the use of energy efficient products in the design), is the way we want to help developing the swimming pool industry.
In 2008 TOPIC is carrying out monitored tests on a domestic outdoor swimming pool to research the benefits of different heating methods, comparing everything including different swimming pool insulation, heat pumps, solar heating, solar covers, and insulated/safety covers.
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Pool Experiment
These test swimming pools were not covered, yet there is still a 7˚c temperature difference.
Two identical miniature swimming pools (500x300x300mm) were constructed and set into the ground to compare the benefits of insulation.
Both miniature swimming pools had a concrete and steel construction which was then tiled, one pool had a 14mm layer of Thermapool applied.
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Conclusion
Both miniature swimming pools were heated for three days with a 1.2kW heat lamp placed 1.5m above both. The pool on the right has 14mm of Thermapool insulation. The differences in temperature in both water and soil temperature clearly show benefits of installing insulation.
Significant heat gains are shown in the soil from the un-insulated pool and a 7˚c water temperature difference between the two pools.

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> 75mm of Thermapool Swimming Pool Insulation will give a Thermal Resistance of 2.5 m²kW.
> 3.75m of dry clay soil will give a Thermal Resistance of 2.5 m²kW.
> 8.75m of rock soil will give a Thermal Resistance of 2.5 m²kW.
These diagrams are scaled to show the amount of conduction into the ground showing the end elevation of a 5m wide x 1.5m deep pool (normal domestic pool 10m x 5m x 1.5m deep).
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Our system Therma Pool 75 mm of internal insulation area of conduction. 75mm of Therma Pool will give a Thermal Resistance of 2.5 m²kW. . |
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Dry clay soil thermal conductivity 1.5 W/m·K (dry) area of conduction. 3.75 meters of dry clay soil will give a Thermal Resistance of 2.5 m²kW . |
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| Rock soil thermal conductivity 3.5 W/m·K area of conduction. 8.75 meters of rock soil will give a Thermal Resistance of 2.5 m²kW |
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Thermapool is the first and only swimming pool insulation of its kind available - there are no imitations - Cheap or otherwise.