11: How does a swimming pool heat exchanger work?
Swimming pool heat exchangers work by transferring heat energy from a hot water circuit, to the cooler pool water circuit, without the two fluids ever coming in direct contact with each other.
Most swimming pools are heated via a boiler, using fuels such as Gas, LPG or Biomass, as the energy source. In theory, the most efficient way to heat the pool water circuit would be to connect it directly to the boiler.
Were this to happen, the chemicals and minerals added to the pool water to keep it safe for use, would quickly erode and damage vital components inside the boiler, leading to premature failure and a costly replacement.
However, by using a heat exchanger to act as an ‘interface’ between the boiler water circuit and the pool water circuit, the boiler is protected from damage and the pool water is quickly heated up to the required temperature for use.
Shell and tube design heat exchangers are extremely popular for swimming pools, due to their efficiency and ease of maintenance. Inside the ‘shell’ there is a bundle of tubes, known as the ‘tube core’, through which the pool water passes in a single direction.
At the same time, hot water from the boiler is circulated around the outside of all the tubes in the tube core. Traveling in the opposite direction to the pool water flow, the boiler water transfers its heat to the pool water, before being recirculated back to the boiler, for reheating.
Both water circuits operate in a continuous heating cycle, until the total pool water volume has reached the required temperature, which is usually around 28 – 30 °C.
Bowman manufactures a comprehensive range of swimming pool heat exchangers for everything from spa pools and hot tubs, up to Olympic size pools.