WHEN designing heating systems and sizing radiators, various factors are required to calculate kilowatt (kW) heat loss for the building and deciding on which type of fuel to use.

So it is with interest that I read in the Business section (The Press, February 5) that an online firm is experiencing high sales of “energy-efficient” electric heating products.

Now I know that modern slim ceramic core storage units have replaced the old brick night-storage heaters running on off-peak electricity and that electricity efficiency is 100 per cent, as opposed to gas at, say, 85 per cent, depending on energy supplier’s charges, which do vary, electric costs in this instance would be around twice as much as gas per kW.

If an on-peak electric radiator was installed, the same output as one heated by a gas boiler, the running cost would be around three times as much per kW. It would be interesting to hear the thoughts of someone with full electric heating and from someone with gas central heating in a similar house regarding annual running costs if that was possible.

Mike Harrison, Millfield Lane, Nether Poppleton, York.