Oil filled or electric radiators?

[Gemma]

Hi all,

Am getting lots of advice for heating!  We have just bought a 3 storey house compromising of 6 (large-ish) bedrooms.  I was told electric radiators are the way to go if you don't have central heating...then I was told oil filled ones were better.  Also how many would I need for a large bedroom?

Would appreciate some other opinions please!

Thanks!

 

http://www.discoverthepyrenees.com

[Dick Smith]

We have some large oil-filled ones (1.5 or 2kW) but in large cold rooms they are really only good for background heating unless you leave them on full for hours/days...

We use a woodburner and gaz heaters for getting the place warm, and the radiators to top up/maintain. You may also have to consider the rating of your electricity supply if you get several.

[Owens88]

Radiated heat provide a good sensation of warmth, but the radiated heat doesn't travel far. Modern wall mounted flat panel radiators may be more efficient at that than oil filled ones.

Space heating needs convection of hot air, sometimes speeded up with a fan. What is best for heating the air and how effective it is at generating a flow is going to be different for different situations..

You probably need to provide both. A room which is purely heated by hot air convectors can feel cold to sit in yet give a dry feeling in the mouth. A room which is radiator only will have 'cold shadows' (remember behind the sofa when the coal fire was on !).

 

[Alan]

[quote user="Dicksmith"]. You may also have to consider the rating of your electricity supply if you get several.
[/quote]

 

This is a good point, we have had guests in all three of our letting rooms for the past 10 days and have found at night when we go over to the cheaper electric we are not able to run the dishwasher or washing machine as the electric cuts out.with the extra load

[Gardian]

We've had to put in electric rads here & they're pricey to buy and to run. Can't really help with which system is best for you - there are so many factors and I don't have the technical competence.

But, if it helps, here's my bro-in-law's info given to me on the watts you need. French opinion is that it's 'over the top', so if you more or less follow it, you shouldn't be cold - and you can always turn down the wick:

Try this!!

 

1.    Lounge/Dining Room        multiply the room volume in m3 by 50.

 

2.    Bedroom                        multiply the room volume in m3 by 40.

 

3.    Kitchen/corridors            multiply the room volume in m3 by 30.

 

4.    Exposed site or north facing rooms allow an additional 15%.

 

5.    French doors/ windows    allow an additional 20%.

 

I have given you all the info for different room so you can see the relationship between them.  Hopefully this gives you the output required in watts.

 

While I have the info this is the imperial equivalent which gives output in Btu's:-

 

1.    Lounge/Dining Room        multiply the room volume in ft3 by 5.

 

2.    Bedroom                        multiply the room volume in ft3 by 4.

 

3.    Kitchen/corridors            multiply the room volume in ft3 by 3.

 

4.    Exposed site or north facing rooms allow an additional 15%.

 

5.    French doors/ windows    allow an additional 20%.

 

Please check this with your man, but I hope it is of use.

 

[BJSLIV]

Here is a manufacturers calculator:

http://www.atlantic.tm.fr/atlantic/calcul/edit/puissance/ch

It allows you to play around with location, insulation, type of room, type of convector.

Don't forget that one reason that the heaters may seem underpowered is because the French approach is to trickle charge the heat into the room rather than a big blast of heat 5 minutes before you go into the room.It alos fits in better with the low power supply that is the norm .

 

[powerdesal]

Ian,

Having very quickly checked your 'rule of thumb' method I would say

that the results are at least 33% over the top, if not more, certainly

in terms of watts ( I dont do BTUs !!!!!!).  Doing the

calculations properly using U values, air changes etc is not

particularly onerous and gives you a much more accurate heat requirment

figure. Whilst you can, as you say, always turn it down, it is not

particularly cost effective to install a bigger system than needed.

Regards

[Quillan]

Having an all electric house please do not forget what somebody else has said, what the amount of current dawn because the largest single phase supply is 60A thats around 15KW, With our rooms heated we can't use a washing machine or a oven else the power trips, even a 2kw electric kettle will trip it from time to time. If you are going t run a B&B having the power go out when trying to cook a meal is a nightmare.

There is a way round this, we have a three channel délestage installed. This device chops power to particular things round the house. The first thing it turns off is the water heaters, then the radiators in the lounge (we have parafine heaters and a wood burner as backup) then the guest rooms. This means we can use the oven without the whole house tripping out every 5 minutes and so far this year (it's our first year with this) it works really well and we have not lost power.

The other thing I would strongly suggest is you consider the Tempo option with EDF, this could potentially save you a fortune but there is a catch. If you hit a red day when you have guests you can't have the heating on because the cost of electricity is like 0,40 cents a unit instead of 0,10 cents for normal electricity so it's 4 times as much. There are things you can do like use parafine heaters (the modern ones are very stylish and efficient with no smell).

The other thing I would say is to 'zone' the house. We have the bedroom areas on one zone and the rest of the house on another. Where as the heating in the main part comes on at 06:00 and goes of at 22:00 hrs the guest bedrooms come on two times a day, 06:00 to 09:00 and again at 18:00 to 22:00. The reason for this is that they won't switch them off and they go out for the day and you are heating the room for nothing. I have seen a system with a switch in each room that over rides the timer for say 30 minutes then goes off again for those that return early or leave late.

To be honest I would really prefer gas or oil but the thing is the prices are going up and up where as electricity in France is only going up a little in comparision (what with it being nuclear) and electricity in a well insultated house is becoming more and more cost effect to the point where one day (we are not there quite yet) when it will be considerably cheaper than oil or gas.

[Gardian]

Steve ...........

I'm sure you're right, but you're not married to my wife! Whatever the opposite of a hot house plant is, she's it. Definitely needs that extra 33%, but I'll sign off now and tell her that she's going to be one third too hot. You'll probably hear the ranting in Sharjah.

Ian