The Thermalec sizing chart is for outdoor swimming pools in the South of England, running from the beginning of May until the end of September. For swimming pools in the North, multiply the heater size by 1.3 - 1.5 depending on the exposure of the pool. 

 

The figures shown for capacity of the pool - in gallons or M³ - are based upon an average depth of 4'6" (1.36m) and are provided as a guide when an exact surface area is not known. 

 

Indoor pools: providing the indoor air temperature is maintained at least 1°C above the pool temperature by an alternative form of heating 24 hours per day, the heater size may be reduced by multiplying by 0.7, but since running costs are related to the size of the pool and the temperature required, not the size of the heater, we advise keeping to the table where possible. 

 

In countries where off-peak electricity is not available, heaters sized at 1kW per 1000 gallons (4500 litres) with the heater operating 24 hours per day, will normally be adequate and will give an 8°F (4.4°C) rise in 24 hours assuming no losses 

 

All information given is an approximation, to get a more accurate sizing please contact our main sales office on +44 (0) 1752 313343 where our staff will be happy to answer alll your questions.