Electric heating for a granny annexe

[Mekondelta]

We have a granny annexe we're creating from a garage and another room in the house.

We need to use electric heating to heat the annexe.

I'm thinking of using infrared radiators to heat the annexe and have a couple of questions:-

- Am I mad? Or is this a viable option? Are there any other ways of electrically heating the annexe cheaper or more efficiently?
- Do I need a radiator in the small kitchenette and bathroom or will heat flow into there by itself. I think with traditional radiators the warm air moves round the house but with infrared it doesn't? I'm guessing they need their own heaters?
- I'll be using an electric shower, and localised water heaters for bathroom and kitchen sinks. Can't see any other way around that.

Anyone else been in this situation and have any advice?

 

[JohnD]

no, but electric heating is so expensive to run, that I have been thinking it is a good use of solar power, if you can put some PV panels up.

I reckon a heated concrete floor slab, or storage heaters, would enable you to smooth out the times when the sun is shining, and the times when you need heat.

With an electric shower as well as electric heating you will be drawing a lot of power. Has your house got enough to spare? What is the rating of your main fuse? You will most likely not be able to use an electric shower in the rest of the house at the same time.

Why do you want infra-red heaters instead of oil-filled radiators?

A granny gets older she may want more and more warmth.

There is obviously some reason why you don't want to extend your central heating into the annexe. What is it?

 

[Mekondelta]

The house fuse is 100A. Is that enough? Upstairs has a conventional shower but electric oven and hob. We'd need at least 2 radiators (one per room) plus anything for kitchen/bathroom.

I've been thinking of infrared radiators because they seemed to be the most efficient type of electric radiator, heating objects rather than the air. Am I wrong?

I don't have the space upstairs really to install a big enough boiler to power the whole house. Not plumbing the whole flat would also save us some money. We'd have to do the electric anyway so no extra cost there.

 

[JohnD]

What sort of boiler have you got? Not a combi? Most modern boilers have more power than the house needs so don't run flat out even in cold weather.

The amount of energy you need to heat the flat will not vary by type of heater, but oil-filled (or hot water) radiators give a more even temperature.

 

[OwainDIYer]

you should consider using Low Surface Temperature heaters.

http://www.akw-ltd.co.uk/product-listing/icare-electric-lst-radiator/

(Other makes are available.)

 

[Mekondelta]

Thanks for all your responses. The LST heaters look interesting! However, looking at our plans and given that we're digging the floor up anyway, seems like we may as well upgrade the water/gas pipes and get gas into the annexe. It's the safer, more well trodden path I think.

 

[kbdiy]

Let's hope granny is going to contribute her winter fuel allowance towards the running costs as well!

 

[Richardthe3rd]

It's all down to leccy tariff, if you can get a cheap rate/standard rate tariff then a 'storage unit' electric type boiler is by far the cheapest to run. A unit like this heats on the cheap rate, overnight or whatever;
http://www.advanceappliances.co.uk/electric_combination_boiler.html

Loads cheaper than these daft panel type heaters to run.

Another option is a split unit ASHP or two, 3-4 times cheaper to run than a standard electric heater;

http://www.coolequipment.co.uk/air-conditioning

HTH

 

[JohnD]

It's all down to leccy tariff, if you can get a cheap rate/standard rate tariff then a 'storage unit' electric type boiler is by far the cheapest to run.

but still not as cheap as gas.

 

[Richardthe3rd]

It's all down to leccy tariff, if you can get a cheap rate/standard rate tariff then a 'storage unit' electric type boiler is by far the cheapest to run.

but still not as cheap as gas.

Never will be John. Lots of Landlords are fitted leccy boilers as it's easier for them & less hassle, but not cheaper for the tenant.