WilliamH said:
................ A radiant floor heater won't directly heat the air the same way a fan or convector heater will.
Hope this helps!
Hello William,
Honestly I'm not trying to pour cold water on your posts, but I do see some technical inaccuracies which may give the wrong impression about the abilities of a product.
You acknowledge We have discussed the capability of of underfloor heating for caravans in another thread, and we agreed that underfloor heating on its own would be insufficient to heat a whole caravan. Interestingly this article also raises the same concerns.
http://www.caravantalk.co.uk/caravan-advice/electrics/electric-underfloor-heating
I have to take issue with your last paragraph (quoted above) The fact is the amount of heat a body (or floor) can radiated is determined by the temperature difference of the surface of the body to its surroundings.
As it is generally accepted the surface temperature of a heated floor should not be allowed to exceed 29C (302K) and for comfort the surface temperatures of the surroundings in a caravan will be about 20C (293K) the conditions will not allow a great deal of radiated energy to be released. This actually means the majority of the heat produced will be lost by conduction into adjoining materials, and convection from the surface. Consequently its a bit misleading to call underfloor heating a radiated system, it does heat the air above it through conduction, which will begin to circulate by convection.
Even with that changed perception of its operation, underfloor heating does have some value in a caravan. Most people find having cold feet quite uncomfortable, and they can even tolerate lower ambient air temperatures if their feet are warm, so the UFH can achieve this by conduction.
In addition the combination of gentle convection of the warm air rising around the lower legs and the long wave length IR radiation also means the occupant does not have to work so hard (Cardiovascularly) to keep their lower limbs warm, so they feel more naturally relaxed.