Pool heating systems

Press, 18 November 1981, Page 32

Pool heating systems

A body of water as large as a swimming pool needs some sort of heating system.

A heater also enables the pool to be used more frequently. Various types of heating units are available, from solar heating panels to oil-fired heaters and to electricity. The pool heater must be capable of heating the pool to the maximum required to cater for the average minimum monthly temperature for the period the pool will be in use. There are two main heating requirements — to heat the total volume of the pool to the required temperature and to allow for normal operating heat losses such as evaporation. As the majority of heat from a pool is lost at the

surface, the area rather than the litre capacity is used to determine the heater required. An increase in wind velocity over the poo! of about skm to 16km can double the heat losses from the surface. It is estimated that heat losses from covered pools are from one third to one half lower than an open pool, depending on wind velocities across the open pool and relative humidity. All pools should have adequate wind breaks or screens to save heat loss from the surface. With the high costs of fuel, a definite place has been established for solar heating. There are two proven methods of heating swimming pools with solar energy — either solar collectors outside the pool or solar radia-

tion through transparent pool covers. A heat pump system has been designed that can also utilise existing piping for solar heating. The heat pump works on the same principle as a refrigerator, but in reverse. The pump extracts warmth from the atmosphere, concentrates it and transfers it to the pool water. Electric pool heaters range from 2kW to 36kW and because they are thermostatically controlled there is no waste of power. The electric flow heater is connected into the pipework of the pool filtration system: Elements inside the unit are connected to an off-peak supply. The flow heater unit contains all equipment for automatic control over power requirements.