I concur with Bob. That aside, here is an additional resource to get information on heating: http://www.getproquotes.co.uk/prices-and-costs/heating-prices.php
 

I realise that Green Building is a small magazine, but do you think that you could actually read these PR puffs before you publish them? This one contains the phrase "Infranomic® heating elements omit Far Infrared energy". Does this mean that they miss it out ? Or is it the wrong word and should be "emits"? It's obviously been copy/paste straight from supplier's brochure since the same mistake occurs there...