Electric heaters

[Hotrodder]

This latest cold snap has caused us to re-evaluate our heating situation. Sitting here with the 14kw fan assisted woodburner running flat out dressed with everything we can fit on at once we are still freezing. I was wondering what other options might be open to us. We have tried varous paraffin heaters but I can't stand the fumes they produce. It brings on wheezing and shortness of breath. LPG gas heaters do much the same and require humping heavy gas bottles to and from the supermarket, etc. Back to electric heat sources then. We have used various radiant electric heaters, fan heaters, and even storage heaters in the past but only as "top up" solutions, not the main source. I would like to assume the technologies have improved over the years and could this sort of thing be practical for a main heat source these days. I know electricity is at an all time high these days but is there any chance it could be an option?
The idea would be to give up on the woodburner and switch to electric. The woodburner is costing €1000 for a few cold months in winter and involves a lot of work. I would expect to put the cost of the logs toward the increase in EDF bills. I was just wondering which of the heater systems is the most cost efficient to run. We don't even dream about a boiler or heat exchanger system, etc. as we don't have the dosh to throw at that. I was thinking individual heaters plugged into kitchen, sitting room, and bedroom.
Any ideas out there, or links to websites that do the calcs?

[niemeyjt]

No idea - but 14Kw of heat - by electricity - may not be cheaper than wood.

I like Halogen/Ceramic heaters to heat objects (i.e. you) instead of the air. Maybe worth a look/test - smaller ones can be had cheaply.

[L Austin France]

ny ideas out there,

14 kw is a lot of heat. Where's it going?
Our 10 kw woodie, which never runs flat out, is more than adequate for our
50m2 lounge with enough residual heat rising to the bedrooms to undress without freezing our bits off.
Insulation & draught proofing doesn't cost a shed load if you can DIY.

[RobertArthur]

@ Hotrodder, the new technologies come as a mix between the old radiateur and accumulateur, less on/off switching going on, from a liitle bit too warm to a little bit too cold, a more constant temperature. Or the infrared panels, not trying to warm up the air, but heating up objects, including the human body. A more direct effect.

I'm not a believer: the PR guys say, 30 to 50 % more efficient than the old radiateurs, type grille pain. Your electric bill will go down. Because all the electric energy of those outdated radiators (ours already 40 years and still doing their best from time to time), goes up in warm air, 1 kW electric input is 1kW of radiated thermal energy, an efficiency of almost 100 %, I sometimes asked: does this imply that with 1000 watt electric input energy I will be rewarded with 1300 to 1500 watt thermal output energy? Sweet sounds of heaven, performance better than a perpetuum mobile. Never got a clear answer in the brico sheds.....

Not a cheap option, usefull for additional heating. Better insulation, reducing air leakage should do the rest to keep you both warm without breaking the bank.

About your installation électrique, a topic I find difficult to avoid. Cut, copy and paste from NFF:

RA, Sun Nov 03, 2019 10:02 pm

A question about this 9 kW boiler. In Mysty's opening remarks almost everything has been mentioned: easy installation, maintenance free, no flue, tiny and silent, and in this case to be used as backup heating for a woodburner. Although not the primary heating source no mention has been made of the puissance souscrite you are supposed to have. Black and white picture: sorry dear, no tv, no lights tonight, electric heating is going to get every electron available. Top priority.

With a 9 kVA puissance souscrite in single-phase you can upgrade to 12 kVA. Higher? You'll have to change to three-phase, 15, 18 kVA or more. See v12mike's 18 kW three-phase boiler, probably the primary heating source. Still simple, but it comes at a price, standing charges and also revamping your distribution board. With a type 2 connection to the grid even more in depth investments, not in gold, in copper wiring.

@ Mysty: interesting follow-up question: LINKY smartmeter for power surveillance or still the old friendly disjoncteur de branchement?

------------------------------------------------------------------------------------------------------------------------------

As LD already suggested: a power shedding system can be your best friend in these cases. Priority for lights and sockets etc., others please wait a few minutes or longer. A simple unit (délesteur) in your distribution board and probably one (or more) contacteurs to switch the many amps. Or a a christmas tree to arrange a form of cohabitation between a 12 kVA puissance souscrite and once upon a time about 25 kW of electric heating: accumulateurs and convecteurs. It used to be interesting, all those litttle red lights indicating the status of what circuit had the honour to receive it's daily bread, only for a few minutes: who is next? Switching from left to right, top to bottom. Trying to keep all customers satisfied.

--------------------------------------------------------------------------------------------------------------------------------

Délestage, power shedding.

And nothing wrong with off-grid heating, you never know.

[Hotrodder]

No idea - but 14Kw of heat - by electricity - may not be cheaper than wood.

I like Halogen/Ceramic heaters to heat objects (i.e. you) instead of the air. Maybe worth a look/test - smaller ones can be had cheaply.

The 14kw was presented in the blurb, probably an exagerated claim. I don't expect to be finding a cheaper source of heat, but more efficient and hopefully a lot less physical work to achieve.

The mrs. found some halogen heaters rated at 2000watts for very cheap.

[Hotrodder]

ny ideas out there,

14 kw is a lot of heat. Where's it going?
Our 10 kw woodie, which never runs flat out, is more than adequate for our
50m2 lounge with enough residual heat rising to the bedrooms to undress without freezing our bits off.
Insulation & draught proofing doesn't cost a shed load if you can DIY.

Our lounge is only about 44m2.
I have dry lined and put insulation behind the placo downstairs but the bedroom is probably the worst culprit. Just a pent roof with no ceiling apart from 50mm thick expanded polystyrene panels on thin batten framework. All windows are double glazed but for some ridiculous reason all face East so no free heat from the sun (when it dares to shine). I put 3/4inch extruded polystyrene down over the concrete floors before laminated flooring. Everything done improved the situation a bit but clearly not enough.

[Nomoss]

The answer probably is to improve the insulation especially the ceilings/roof.

We have 30 cm of blown-in cellulose below the loft, but even that could be improved.

[RobertArthur]

Isolation des murs intérieurs : quelle épaisseur d'isolant choisir ? At least 12 cm/18 cm nowadays. In the late 70's visiting Norway: a huge log cabin in the mountains, dimensions inside: much less. About 30 cm of insulation, little windows, triple glazing, warm and cozy.

[Hotrodder]

Very little opportunity to increase insulation. Very little loft to insulate. Any increase will have to be hung from a false ceiling reducing internal volume and adding weight to the lightweight structure.

RA: Your link to Aterno offers a lot of useful info explaining the different types of electric heaters. Many thanks.

And also: We are on the 6kva abonnement so I suspect this puts the kibosh on any idea of electric heating.

[L Austin France]

All windows are double glazed but for some ridiculous reason all face East so no free heat from the sun

Must be a Breton thing. All of the main windows on our house faced east until I built a single storey kitchen along the rear with west facing windows.