Electric Radiators V LPG central heating.

[cliff1010]

Can I ask some advice I am in the process of converting a building into a granny Annexe and am undecided on what to go for. we are not on mains gas and only have LPG. I like the idea of the electric rads as can fit myself no expensive boiler fitting and engineers. I have seen various companies and wonder if anyone has electric rads and can tell me if they like or dislike them. I have been forwarded loads of info re how efficient they are but nothing is as good as a personal referal from someone that uses them already.

One quote I have had shows the one bed annexe should have 3 rads approx £1000

Thanks Cliff

 

[londonboy]

I would use LPG, its cheaper in the long run.

Your existing electricity supply may not have the capacity to run a house and annex (with electric heating).

 

[EFLImpudence]

Electric oil-filled radiators are quite good.

 

[ban-all-sheds]

Air-source heat pumps are cheap to run, as the heat you get out will be 3-5x the amount of electrical energy you put in.

 

[Scoby_Beasley]

I've lived in places with oil c.h./gas c.h./electric (of whatever form) heating.

Electric is the only one I've ever been frightened to turn on as it would be cheaper to burn notes for all the heat you ever got!

 

[ericmark]

Electric must be bottom of the list. It's what you use when other forms fail while getting it repaired.

People like the http://www.energysavingtrust.org.uk/ will give you the figures but do remember they want to fly the green flag and miss out some of the bad bits.

Any one who has lived in the days of smog and coal fires would never dream of fitting a wood burning stove but these guys still promote them so do exercise some care.

 

[londonboy]

Air-source heat pumps are cheap to run, as the heat you get out will be 3-5x the amount of electrical energy you put in.

Which are suited to well insulated properties, presumably this annex is a new build (well insulated) so ASHP may be the way to go.

 

[cliff1010]

Thanks for all the advice;

the property is a conversion from a stable and insulation will be as current spec required. I am just concerned that the cost of the LPG central heating install over that of the electric.

It would be good to find out ( I will check the link to the energy saving trust ) the costs per kw for all. I think if we do have to go down the boiler install route it will have to be LPG

but some of the info we have from these electric rad companies state as little as 1p per hour to run. it that all rubbish then ??

Cliff

 

[bernardgreen]

but some of the info we have from these electric rad companies state as little as 1p per hour to run. it that all rubbish then ??

Averaged over a year that might be true as the heaters won't be used in summer. One kilowatt heater on for an hour uses one unit ( kilowatt hour ) of power, That is somehwere arounf 10 to 15 pence for that hour. So if it iwas on for two hours in a day then the lowest average cost per hour would be 2 times 10 divided by 24.

As you are doing the conversion think about putting in more insulation than the minimum required by building regulations. Then install active ventilation that recovers heat from air being expelled and uses it to heat the incoming air. There are units which chill the outgoing air to near freezing to make a over all gain in heating. The only problem with this is power cut leaves the house without ventilation other than opening windows

 

[cliff1010]

Thanks thats helpful, now totally confused looking at ground source heat pumps also.

 

[ban-all-sheds]

Big job to install those - AFAIK unless done at the same time as the groundworks for a large building project you never get a return on the investment.

 

[cliff1010]

Yes I spotted the grant available then wrote my post and took 3 or 4 web sites before seeing it could cost 14K thats out of the budget.

 

[SimonH2]

Air-source heat pumps are cheap to run, as the heat you get out will be 3-5x the amount of electrical energy you put in.

Have you looked at the spec sheets for them ?

They may have a CoP* of 3+ in warm weather, but at the moment you'd be lucky to get more than 1 out of some of them. I believe they often have an immersion heater in them which is used instead of the heat pump when it gets cold outside ! They also lose performance considerably as you raise the required outlet temperature (so forget about heating the DHW).

* CoP (Coefficient of Performance) is the technical term for the ratio of heat out (heating) or heat in (cooling) to power in. CoP in heat mode is usually around 1 higher than CoP in cooling mode (think about it).

 

[ericmark]

I have had a guy around trying to sell my Father-in-law This system in our case where we have gas not really worth it but may work out OK for you.

 

[SimonH2]

Hmm, claims that they can do up to a CoP of 3 - OK everyone can do that (under the right conditions).
And heat water to 90˚C - OK, that's doable with the right design.

But get hot water, and a CoP of 3, and with our climate - lets just say I'm 'a tad sceptical'.

In this country, if you have a mains gas supply, then on cost grounds you will not beat a decent condensing boiler properly installed so it does actually condense. I believe the economics are different if you are using LPG.