Heating a pool or jacuzzi through the Egyptian winter

What sets the size of the heater

Four things: the volume of water, the temperature you want, which months you want to swim, and how much heat the pool loses. Most heat is lost from the surface, through evaporation and wind, especially on clear winter nights.

An outdoor pool in Sahel in December loses far more heat than an indoor pool in a Cairo villa. Indoors, the pool hall’s air and humidity are part of the design too.

The cover comes first

A pool cover is the cheapest heater there is. On at night, it cuts evaporation and holds in the heat the heater put in during the day, so the heater can be smaller and runs less.

For a jacuzzi, a fitted insulated lid does the same job and keeps the water ready to use.

Heat pump, boiler or solar

A pool heat pump takes heat from the outside air, like an air conditioner in reverse, and gives back several units of heat for each unit of electricity. It warms a pool steadily over days and then holds it there, which is ideal for Egypt’s mild winters.

A gas or electric boiler with a heat exchanger heats faster, so it suits jacuzzis and pools that are heated only now and then. Solar collectors can carry much of the load in autumn and spring, with another heater for the coldest weeks. Where the home already has a heat pump or boiler for its heating, it can sometimes serve the pool too.

Fitting it to the pool equipment

The heater connects into the filtration circuit, after the filter, and needs space in or near the plant room. A heat pump needs open air around it and a place where its fan will not disturb anyone. Pool water chemistry matters: heat exchangers must suit chlorinated or salt water.