Most cost effective way to heat...one room

FlaatusGoat

Trying to save one the heating bill, and I'm after some advice on two heating methods. Which is cheaper, basically. First option is (or was until it broke) the heated blanket I had on my chair. Only bought it two weeks ago and it was brilliant until it broke today. I'm guessing the thermal fuse was tripped. Never mind.

Second option is to use the combi-boiler. Probably a no brainer but I wanted to compare the two. Additionally, I've turned off all the valves on the radiators in the house. Except for the kitchen where I'll be with the door closed and the curtains drawn. I've also cranked the boiler flow rate right down and my thermostat is set at 17c maximum.

Will the heated blanket still (if less practical) be substantially cheaper to run?

tacpot12

Trying to save on the heating bill by not heating the house is a false economy when the temperature outside is below freezing as you will get frozen pipes inside the house. While the outside temperatures are above freezing, it's ok, but you will get condensation and damp problems if you don't heat the house a bit. 

The boiler will be about 90% efficient while its running, whereas the electric blanket (when it works) will be 100% efficient, but you need to know the price per kWh you are paying for gas and for electricty to workout how much each is costing you, and hence which is cheaper. You also need to know how much heat the kitchen loses (at 17C) as the cost to run the boiler will be 11% more than the heat that is lost from the kitchen. If you google "calculate heat loss in a room" you will find a number of online calculators that  will help you figure out how much heat your kitcehn loses.  

Grumpy_chap

What activity do you do in the one room that you plan to heat?  

If you have used a heated blanket and that worked well, then my experience in my home office may be relevant.  Obviously, in the home office I spend much of the time in the same position and limited movement.  Is your environment like that?

I use a heated footrest and find it works really well as it is keeping me warm, not the room.  There are several types available, but this is the one I have:
https://www.amazon.co.uk/Fellowes-Professional-Climate-Control-Adjustable/dp/B002YNU7YK

I actually had a thread on much the same subject:
https://forums.moneysavingexpert.com/discussion/6306330/wfh-heating/p1

You may find that an interesting read.  There may be some differences if your room is living / dining room rather than home office / study.

comeandgo

If your heating blanket has stopped working after two weeks take it back to the shop.  You are also trying to compare apples and pears.  A heating blanket heats you, not the room.

grumbler

I think a single blanket is about 150W at max setting, i.e. about 1kWh,  for 6-7 hours.

It has a built-in thermostat, so can be not permanently on, depending on the conditions.

No way can it heat a room, as per your title, but it's certainly cheaper for heating you than heating the entire room with a boiler.

Murmansk

Well I've been running my central heating (combi boiler) for three hours per evening with all the radiators off except the one in the living room. It's a double panel double convector radiator about 1.5 metres long and the room is a large one with high ceilings in a Victorian house with a double glazed bay window.

This costs me £1.50 in gas for each three hour period.

FreeBear

grumbler said: I think a single blanket is about 150W at max setting, i.e. about 1kWh,  for 6-7 hours.

A blanket is possibly less than that. I have an electric blanket on my bed - Just 60W, and keeps me toasty even on the lowest settings.

A combi boiler, even modulated down to its lowest output could well be running at 7KW until the thermostat kicks in. Depending on the size of the kitchen, a small electric fan heater may be enough to heat the space.

grumbler

FreeBear said:

grumbler said: I think a single blanket is about 150W at max setting, i.e. about 1kWh,  for 6-7 hours.

A blanket is possibly less than that. I have an electric blanket on my bed - Just 60W, and keeps me toasty even on the lowest settings.

Mine is 150 (max). And I checked this one - https://www.argos.co.uk/product/9231856?clickPR=plp:2:44 (see Q&A).

FlaatusGoat

Well, it appears my electric blanket died yesterday. Probably overheated and blew the thermal fuse. Once that goes and that's it. With retailers evidently price gouging electric throws (which would have probably been more suited to my application) I've decided to buy a 12v to 240v converter (£15) and I have a spare electric heated car seat cover that I no longer use that's extremely powerful drawing 3-4 amps @ 12v. That with a regular blanket over me should be overkill even in the sub-zero forecast next week.

andre_xs

Personally, I also can wholeheartedly recommend hot water bottles: One for the feet and one on the lap.

The only thing to consider really, as mentioned by others, is that you make sure that you don't get problems with condensation, dampness (damage to walls, ceilings, etc), mould, etc. I'm not an expert, but there should be sufficient information on the internet. For example, maybe you need to air more/less, and/or it's worthwhile to 'heat up' the whole house twice a week for a few hours.

casper_gutman

This BBC podcast is pretty relevant:
https://www.bbc.co.uk/sounds/play/m001dxtx

Spoiler alert: gas is cheaper, but has the disadvantage that most currently installed central heating systems will make it inconvenient to heat one room. To get the required zonal control you'd most likely have to run around the house turning all the TRVs in other rooms down/off, and even then there may well be a rad somewhere (in the bathroom?) which is "always on" whenever the boiler is producing heat. The electric heaters all cost the same (unless you're looking at a heat pump) so the choice between them comes down to other factors relating to user experience and acceptability or otherwise of noise and high surface temperatures.