Electric heating

[Observer]

I'm looking for some pointers on electric heating in an apartment block comprising 11 apartments constructed ~35 years ago. It is a 'shared ownership' development so has different occupants each week.

Each apartment is two bedrooms (one en-suite) with living room/kitchen and a second bathroom. There is no mains gas so the heating is all electric and comprises night storage heaters with convectors for 'top up' heating. The radiators - all Dimplex and installed 5-7 years ago - are as below:

1 x CXLS18N (2.5kW) for each bedroom
2 x CXLS24N (3.4kW) for living room
1 x XLS12N (1.7kW) for hallway

So installed capacity is 13.5kW plus (say) 3kW immersion heater for hot water.

The development is on a commercial tariff so (at present) doesn't receive any Government support and pays 20% VAT, so the winter heating costs are expensive - for example >£250 for a single week in one apartment at the end of January. The usage (nigh tariff) was 480kWh for that, which could be accounted for by (say) ~4.5 hours/night for heating (425kWh) and the rest for hot water.

I'd be grateful for any general pointers on whether anything can be done to improve heating efficiency and reduce costs. As a starting question, is the radiator technology reasonably up to date?

TIA.

 

[oldbutnotdead]

Oh dear.
Insulation. Is there any? Windows- modern A grade double/triple glazed or aged steel frame things?
Night store heaters have always been a bit rubbish- their poor performance was mitigated by them charging up on cheap rate electricity. Without that benefit they are an expensive way of keeping the flat comfortable- likely better off forgetting about them and using your panel heaters (assuming they have time and temperature controls).
Electric heaters (even night storage ones) are near enough 100% efficient (as in every watt consumed gets converted into heat) so beware the witchcraft purveyors.
Are you responsible for the whole building or just one or 2 flats?

 

[Observer]

I'm chairman of the owners management committee. I own two weeks in July so not so much of an issue for me but £250 for one week!!

The windows are all double glazed and relatively recent (<10 years) but there's a lot of them as it is a waterside location. Even the cheap rate electricity is 43p/kWh.

What do you mean by "panel heaters"? The convector function on the existing storage heaters? Or do you suggest they should be replaced?

Edit
Not sure about insulation. I could look into it but it would be major piece of work.

 

[Observer]

Oh dear.
Insulation. Is there any? Windows- modern A grade double/triple glazed or aged steel frame things?
Night store heaters have always been a bit rubbish- their poor performance was mitigated by them charging up on cheap rate electricity. Without that benefit they are an expensive way of keeping the flat comfortable- likely better off forgetting about them and using your panel heaters (assuming they have time and temperature controls).
Electric heaters (even night storage ones) are near enough 100% efficient (as in every watt consumed gets converted into heat) so beware the witchcraft purveyors.
Are you responsible for the whole building or just one or 2 flats?

Sorry if I'm slow to catch on here. Is your suggestion that an electonically timed/controlled panel heater system that turns on/off according
to temperature settings could be more economic than night storage heaters that (mostly) use night rate energy.

Is this the type of heater you have in mind?

Dimplex Electronic Panel Heaters

 

[oldbutnotdead]

Ah, you didn't mention you had a dual rate tarriff for the night store heaters. Problem there is the things tend to leak heat (so rooms are very warm overnight) and will be pretty much depleted by early afternoon so you need additional heat for the afternoon/evening.
Yeah it was the convectors you referred to, I assumed they were additional to the night store heaters.
It's not really about efficiency, more to do with how you heat the place to suit your lifestyle.
I assumed (when I saw 'flats') concrete slabs everywhere. Concrete is a rubbish thermal insulator, so is brick.
Best way to save energy on heating is to reduce the leakage- so insulate and draughtproof everywhere.
Any scope for solar panels? Heat pump(s) for heating dhw?

 

[ericmark]

more to do with how you heat the place to suit your lifestyle

This is the major point, all well and good saying fit a heat pump, but is there room to fit one? And do the flats need cooling as well? We tend to only look at our own homes, and only when one moves do you realise how much things change home to home.

My last house never seemed to get too hot, but parents house and this house the living rooms catch the sun, parents planted apple trees to shade out some of the sun, my house I either use a portable AC or live in the dinning room in summer months.

But parents house reaction speed on the heating system was very important, we swapped to electronic TRV heads to increase the speed at which the radiators turned off when the sun hit the windows, with that house storage radiators would be a non starter.

Life style also a big thing, when my wife and I worked, we did not heat house 8 am to 6 pm, again storage radiators would not work, but now retired, want home warm 24/7, so looking at my boiler keeping the house warm, not re-heating as fast as possible when we get home.

I know some flats gas is banned after the Ronan Point failure. But around here LPG gas central heating is used, as well as oil, and both are cheaper than electric.

You have a problem when the flats are used as holiday homes, as any cost to heat the home is not going to help those who have summer slots, so maybe easier to sell the idea of heat pump when it heats and cools.

 

[Why Not Indeed]

I could look into it but it would be major piece of work.

Besides "turn the thermostat down" and "thicker curtains", anything you do here is going to be major and thus require cooperation from all the owners to fund it. I am struggling to think of anything else you can do at an individual apartment level that will help.
Improving insulation is the #1 thing to do, it will work as a "force multiplier" for every other measure you take.
I suggest you seek professional advice, as many of the domestic solutions aren't particularly relevant in a larger development.
I assume that you've investigated the VAT you're paying on electricity and that the 5% rate is not applicable here?

 

[flameport]

whether anything can be done to improve heating efficiency and reduce costs. As a starting question, is the radiator technology reasonably up to date?

Insulation first. Otherwise you are just pouring money away regardless of what heating is installed.

Storage heaters user cheaper electricity, but have the massive disadvantage that you will be heating the building 24 hours a day whether that's required or not. 50 years ago that was valid for a lot of homes - not so much today. The difference between day and night rate for electricity is also far less than it used to be, and it's usually more expensive in the day if you have a cheaper overnight rate.

Other electric heaters that can be used as and when required may well be cheaper to use overall if the property is not occupied and heated 24/7.

Beware of companies selling magical 'efficient' electric heaters containing miracle ceramics, gels, cores and whatever else. Ultimately any direct electric heating coverts all of the energy input into heat whether it's a £50 item from Argos or an £800 one from some boutique heating emporium.
Heating costs are a direct function of how much energy is required to heat a particular space and how long you heat it for. For any given heat source, the only ways to reduce the cost are to reduce heat losses with more insulation, heat it for less time, or heat it to a lower temperature relative to the outside environment.

 

[brig001]

7 year old storage heaters will be a lot better than those from the 1970s; our 20 year old ones are not too bad, but nowhere near as good as modern Lot 20 compliant ones of course
Are the heaters definitely coming on at the right times? Best way to check this is to read the day and night meters last thing at night and first thing in the morning. The day rate should not have increased significantly overnight
As others have said, insulation, but also check for draughts - in our flat the builders left half a breeze block out for the cold water pipe. Filling that made quite a difference

Brian

 

[SpecialK]

Any space to fit an ASHP?

 

[ericmark]

There is another thread where the high heat retention (HHR) storage heater has been talked about, it seems EN60531:2000/A11:2019 has been withdrawn, so not sure what is going on, but it seems some storage radiators have a fan in them, and are designed to not allow as much heat to escape when the fan is off.

Using water tanks similar to used with solid fuel heating can help.

The idea is multi methods can be combined, and the water tank is very well insulated so can retain the energy for a long time, mainly designed for use with the wood burner as for a wood burner to work efficiently without particular emissions it has to work at a set rate.

The down side is the cost, the storage tank is well over £1000 and my brother-in-laws old house needed two and the floor reinforced to take the weight. It is like when the EPC report says insulate the floor as first point to increase energy rating, it is far too expensive to do as a retro job, only really an option with a new build.