Dimplex has described claims currently being made about some electric appliances in the market as confusing and "unachievable".
Chris Stammers, marketing director at Dimplex, said: “Some surprising assertions with regard to efficiencies and running costs are being made in the marketplace at the moment. But frankly, many of these claims are unachievable, and specifiers and installers need to be able to see through the hype, by making some straightforward comparisons.”
Dimplex said that any electric resistance heater can only ever be 100% efficient. A 1kwh input of electricty will transfer 1kw of heat into a room for one hour, and the company said it’s not possible to improve on that.
Not all electric heaters operate in the same way. A fluid-filled radiator transfers the heat uniformly around the radiator, giving more radiant than convected heat, compared with a convector heater. A slower warm-up and continued release of heat after switch-off are also characteristic of the fluid-filled design. But they both release exactly the same amount of energy to the room.
Some electric radiators, filled with so-called ‘thermodynamic’ oil or water-based fluids, claim to be more efficient and even more economical to run than either storage heaters or panel convector heaters.
Dimplex said that neither the European Commission nor the government’s SAP system of energy ratings recognises the claims of these ‘thermodynamic’ appliances, with both stating that the efficiency of all electric room heaters is 100%.
When it comes to running costs, Dimplex said storage heaters that use low-cost, off-peak electricity to heat a given property will always be cheaper to run over a 16 hour day than direct-acting heaters which use day-rate electricity – whether these are fluid-filled or convector heaters.