Heating

Press, 26 November 1980, Page 20

Heating

Pool water frequently drops below the 20 deg. most swimmers find chilly, even when air temperatures are well above this, so a pool heater is a good investment. The cost of operating a heater hooked to the filtration system depends on many variables. The obvious ones are the volume of water and its surface area, but others include the temperature rise needed to off-set daily heat loss, wind speed and the humidity of the air. The effect of all these can be reduced by enclosing the pool or, much more cheaply, using a cover that traps solar heat. The cost of the energy used for heating is a major factor in the price of warm water.

A new possibility in the electric line-up is the heat pump. The idea is not new but has only recently been employed in a heater package sufficiently small and cheap for private pools.

The basic principle is like that used in a refrigerator,. only in reverse. The heat pump extracts warmth from the atmosphere, concentrates it and

transfers it to the pool water.

Solar heating using roof collectors requires an auxiliary pump. An unshaded.’solar heated pool, protected from wind and covered with an air-cell “solar cover” when not in use, can provide comfortable swimming well into autumn The solid fuel pool heater has advantages, though. It is much easier to install than either a heat pump or a solar panel system and does not depend on the vagaries of the weather. There is no mess at all associated with electric pool heater and no pollution, either. They range from 2kw to 36kw and thermostatic control ensures there is no waste of power Natural gas heaters with sensitive thermostats provide another possible choice in the North Island but it is likely to be a while yet before supply makes this an option south of Cook Strait.

Similarly, the constantly rising cost of fuel oil is reducing the attractiveness of large-capacity, oil-fired jet burners.