Best portable heater for a big room

[Stringagal]

Our attic bedroom is freezing on a morning, it’s a big room with one radiator that’s sufficient when it’s not sub zero temps outside.

What is the best/quickest - and cheapest - way of heating such a large space, just needs to be on for 30 minutes in the mornings while getting up and dressed.

Thanks!

Electric convection I would say. Heats up quickly, the heaters are cheap to buy but pricey to run. But probably less pricey than running gas for the entire house.

I have a bog standard switchable one that can tune the output power. 700W is enough to keep the home office warm.

Alternatively have you considered just upping the Ch loop temperature on the boiler.

Another thing you could do is increase the radiator output.

If it is a single radiator then you could replace it with a double of the same size and double the output power.

Gas is 4x cheaper than electric.

Thanks @GasPanic I think in time we need to get a much bigger radiator in there, but it won’t be this winter. I’ve already upped the CH temp, the rest of the house is quite toasty.

I have a tiny halogen heater that doesn’t seem too costly to run, I use that in my little office. I was wondering about getting a big one of those? Daft question but does eg a 400w heater cost a third of the price of a 1200w to run?

Yes correct.

It will be ((wattage in W)/1000) x price per kWh,

so if it is 30p per kWh a 400W unit will cost (400/1000)*30=12p per hour to run.

A lower wattage heater will also warm the room less though so you would need to run it longer to warm the room up by the same amount iyswim - swings and roundabouts.