Cheapest way of heating one room

chris1973

Even if she has the central heating on all day she says she does not feel the benefit

When was the last time the system was checked and serviced?. Seriously, if a fully working gas central heating system is struggling to warm one room then a domestic convector heater isn't going to be a magic bullet.

A double sized wall mounted radiator is rated at around 3.2 - 4KW output, even a single radiator of a size running a windows length will produce 2.6kw easily. Compare this to the output of a 2KW convector, which is.....2KW

Provided the heating system is working correctly, if a couple of red hot central heating radiators aren't heating the room adequately, then there is little chance of a single 2kw convector heater, being any more effective.

Even an average sized (4.5m x 6m x 2.5m high), reasonably insulated room will require around 4.8KW of heat output to maintain a steady 21c when its 0c outside. I envy anybody who can comfortably heat one main living room, and at the same time, background heat another all from one single 2kw heater.

You can work out the 'heat input' based on your room size by using the calculator here:- http://www.flickeringflame.co.uk/tech_detail/tech.htm

If the central heating is struggling to warm the property then I can only assume that its very poorly insulated, in which case, whether you use Electricity and Gas its going to be both wasteful and extremely expensive.

Therefore the only conclusion really, unless money is available to better insulate the property would be to stop trying to heat the interior altogether other than to keep damp at bay, and instead concentrate on heating the person.

In this respect, a heated throw is going to be the best option. consuming around 100W - 150W it is the most economical form of personal electric heating there is, even compared to an halogen heater with a loading usually between 400W and 1600W

An Electric blanket will also consume a similar amount of electricity as the throw, so the best advice I can give as to the original question which was centered around the cheapest form of heating, would be to use an heated throw whilst sat watching TV and then an electric blanket to preheat the bed and then keep her warm whilst asleep. Switching between both options during waking / sleeping would probably cost no more than 30p in Electricity per 24 hours of toggling between the two, which is roughly exactly the same as it would cost to run a 2kw convector heater for around 2.5 - 3 hours!

Not the most practical solution as far as moving around the house is concerned, however when sitting still for long periods and sleeping, its about as economical as you will get.

rogerblack

In very old houses with little or no insulation, you can heat one room far, far more cheaply than the whole house, simply as the insulation of the outside walls is broadly comparable to that of the interior walls.

The problem with trying to do that with modern houses is that the relative saving isn't as high.

A couple of issues.
In times past, when heating one room, it would typically not have been heated to close to 20 or 21C.
The rise in living temperatures over the past decades of cheap fuel and moderately improving household insulation is very noticable!

In the past, the energy needed to heat one room - compared to the whole property is not too far off what the calculator Chris mentioned implied.

If you heat 1/10th of the volume, you use 1/10th of the power.

Now, however, with increasingly well insulated homes, it doesn't work that way.

The interior walls are no longer about as insulating as the exterior ones, the exterior walls are vastly more insulating.

This means that your ability to heat one room of a property is vastly diminished, as the interior walls conduct heat 20* as easily as the outside walls.

Of course, this doesn't make the one room harder to heat compared to the uninsulated case - it just means that the savings you can make differ.

In a very old uninsulated property, heating 1/10th of the volume may cost you 1/10th of the amount it normally costs to heat.
In a modern property however, heating 1/10th of the volume may cost you 1/2.

Sure - the total energy used is less, in absolute terms, but not in relative terms.

I heartily agree with electric blankets/throws.
I'm lying here, with the temperature at 12C, with a couple of blankets over me.
If I turned the electric blanket on full, I'd be sweating in about half an hour.
Even last winter, when it was 5C in the house, I couldn't have it on full.

On full, it uses 60W.

To answer the original question - perhaps in an unhelpful manner.
Last winter, I was living in a mostly uninsulated house, apart from attic, which I was heating to 5C.
Now, with about 150 quid outlay for insulation from ebay, and some plasterboard, I've converted one room into a very well insulated box - to the degree that simple bodyheat will heat it noticably, and with around 500W I can heat it to 20C with 0C outside.
Over the summer I'll be insulating the rest of the house, but this one warm room will be where I'm hibernating this winter.

grizzly1911

rogerblack wrote: »

I'm lying here, with the temperature at 12C, with a couple of blankets over me.
If I turned the electric blanket on full, I'd be sweating in about half an hour.

Just being nosey - where are you at 12 degrees?

I am sitting in our house, most internal doors open, fully insulated and it is 19 degrees with no added heat apart from TV and a few energy saving bulbs?

As you and a PP have said is it possible to add insulation and draft proofing to improve things? Grants are available. The biggest difference I have noticed is more even warmth throughout the house particularly upstairs which also cuts out draft downstairs.

rogerblack

grizzly1911 wrote: »

Just being nosey - where are you at 12 degrees?

I am sitting in our house, most internal doors open, fully insulated and it is 19 degrees with no added heat apart from TV and a few energy saving bulbs?

As you and a PP have said is it possible to add insulation and draft proofing to improve things? Grants are available. The biggest difference I have noticed is more even warmth throughout the house particularly upstairs which also cuts out draft downstairs.

Scotland.
The house is poorly insulated, and I have only around 150W of electrical devices on average.

Grants are not applicable.
Cavity wall is out, and the loft is already insulated.

Poorly insulated = walls are constructed of 50cm stone, 5cm air-gap, plasterboard.
This is around 1/20th as insulating as a modern spec house.