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Solar Thermal Warms Hot Lava Pool in Hawaii

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Here’s an original idea. The Hawaiian pool builder PacificGunite makes molds of real lava into poolside decking, then incorporates passive solar thermal heating elements into the thermal mass created by the concrete to soak up the heat of the sun and transfer it into the pool.

Passive solar thermal is the best way to heat your pool without carbon emissions: let the sunshine do it. This company builds on that with artistic recreations of lavaflows to supply the thermal mass.

The technique employed by PacificGunite builds on the ideas used in radiant flooring. In a radiant floor, a solar collector on the roof (or a basement water heater)  sends hot water to rubber tubes embedded in a concrete or mortar (and stone) floor which then radiates heating up through the thermal mass of the concrete to warm a house.

In this case, the opposite occurs. There is a circulating system of water going through these rubber tubes that are set into the deck by the pool.

As the pool pump is running to clean your pool, some of the pool water is diverted through the rubber tubes. Once the thermal mass of the Lavacrete has been poured surrounding those rubber tubes, that sunshine warmth soaks into the Lavacrete and transfers to the water in rubber tubes. The warmed water goes into the pool while the next lot of cool pool water is fed into the rubber tube system to be warmed. The hot sidewalk is cooled as the pool water becomes warmer. Automatic controllers regulate how warm the water will get.

And in case you just can’t get enough of lavaflows outside; you can also make your living room into a lava lounge. PacificGunite certainly has made some great molds of a force of nature.

Source: PacificGunite