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by alison1971 » Tue Jan 06, 2009 3:37 pm

If getting a new gas supply is going to be really expensive, and I do believe it would be....Could economy 7 be the way to go in a house with no heating?
Would economy seven act as efficiently, bearing in mind this house is only small? And does anyone have a clue how much economy seven costs to set installed. Would be 6 or 7 heaters ??

any opinions / advice is greatly received

I am ok at diy and decorating etc, will give any job a go, but if i have no idea or too little info...i have to ask....a little knowledge is mighty dangerous :wink:



by ericmark » Wed Jan 07, 2009 2:20 pm

Economy 7 is a tariff not a heating system when electricity used in a 7 hour slot is sold at a much reduced rate but electricity outside this time is more expensive.
For it to work energy needs to be stored and items like dish washers, washing machines and tumble driers need to run over night.
There are two main methods to store heat.
1) Heat up bricks with heavy iron content to around 1000 deg C and hold them in an insulated box with adjustable vents so heat gained at night can be released slowly through the day.
2) Heat up water in a large insulated container and circulate it when heat is required.
The first is cheaper to install but control is somewhat lacking and a smaller water heater is still required for domestic water anyway.
The second is far more controllable being able to store heat for a week if required but costs more to install.
For the latter there are also two types those which store the water at mains pressure and those which use a header tank. In both cases the shower can be run from mains pressure water but the type which stores water at mains pressure needs an annual inspection.
Of course electric showers are out and you need to used stored water for showers as during the day electric cost so much.
The old brick system with wife and children at home during the day may work OK although just before the power switches back on a night it tends to get cold just when you could really do with it getting warmer.
However the water system can nearly be switched completely off in the day and where all occupants of the house are at school or work it is a far better system.
Also the wet system can be combined with solar power so reducing the bill still more.

You must also consider noise and running washing machines, dish washers over night may be OK in a house where they are remote from bedrooms but starting up at 11 pm may not be best option!

I would expect Gas heating will be far cheaper than electric by time you include all the work required.

Also electric normally has a 100 amp limit and this is for 7 hours so total amount of power per day is 6.7Kw/Hours average but most gas heaters will be around the 27Kw/Hours for the smallest which means in any large house it will struggle to give enough heat using the Economy 7 and will require a boost. There are other systems I think there is an Economy 10 which gives a boost at some point during the day.

Also to work well you may need to change washer, drier, dish washer etc. to used the cheap power. So I think it may work out more expensive than gas to fit as well.

Normally it is only used where Gas is not available.

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by mattpark » Thu Jan 15, 2009 10:22 pm

To get the gas board to fit a gas supply to your house will be expensive. To move onto the Economy 7 tariff will cost nothing, but to wire up and install the storage heaters will cost you a bit.
I have used Economy 7 storage heaters and I thought they were fine - but not as good as gas ctl htg.
As you house is small I would say Ec 7 is your best bet, but ensure you have timers on all your major appliances so to use them at night when the 7 hour cheap tariff (Ec 7) is available. Remember if you change to Ec 7 your day time unit rate will increase noticably.
Finallly, consider how many people are at home during the day as this will affect the heating demands and times units of electricity is used.


by ericmark » Fri Jan 16, 2009 3:11 pm

I am not saying this is what you want but take a look or ... enDocument To see how whole system works look at ... nt_how.pdf very easy to follow. Their main site is one of the things I have looked at is difference between vented and non vented especially in maintenance costs.

The big problem with old brick system was you could not turn them fully off so you also heat the house when no one at home and when it turns out to be a warm day. Also it is not central heating but individual heating in each room so if your not using a study or spare bedroom you can't turn it off yet be able to change your mind at a moments notice. With the exception of a few specially designed houses with central heat store room and ducted hot air the brick system was separate to each room.

With the wet system you have much more control as to where and when you used the stored heat plus can use multi-fuel with solar, electric and any other heat source so if you latter changed to gas or oil only a boiler will be required the rest is the same for all types of heat source.

I have two boilers and the one for hot water has never been very good and I was considering one of these systems to replace hot water boiler so all heated from one gas boiler. But it would also allow if the boiler was to fail to use electric so giving a better back-up system.

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