Type of heating for conservatory conversion?

wittynamegoeshere

Yep, energy in = energy out.

If they're still hot after switching off then that's because you've paid for some heat that's still trapped inside it.

Sadly the likes of Fischer and other cowboys try to create the impression that you somehow get this for nothing.  You don't, it's rubbish.  Also they state that their heaters consume less because they switch on and off.  If a 2kW heater is on half of the time then, on average it consumes 1kW of power.  But it still only emits 1kW of heat, not 2kW.  A 2kW fan heater running flat out would use twice as much power but would emit twice as much heat.

You don't get owt for nowt, be extremely suspicious of any heater company that even mentions efficiency, the chances are they want to bamboozle you with fake science to justify a joke price.

The one exception is the heat pump.  This really does use magical fairy dust.  Actually it doesn't but it absolutely does output more heat than it consumes in electricity, but this is genuine.