Electric heating

LongtermLandlord

I have small (one and a half bedroom) cottage that I have rented for a number of years. It is fitted with night storage units that are over 20 years old and an Economy 10 meter. It was Economy 7 until a couple of years ago when the old meter was changed and the supplier said that Economy 10 was the only option if sticking with night storage. It also has a smart meter.

There is no gas in the village and no room for oil tanks, heat pumps etc. so I think electric heating is the best option - but which one?

I get on well with my tenant and their preference is for electric radiators. I think that is mostly driven by relatively high electric bills. I have asked them to check the meter is working correctly (clock, timing) and what percentage of their electric use is day/night.

Regardless of that, the units need upgrading/changing but, as it's going to be a reasonable investment, I'd like to make sure I do the right thing for the long term to provide an effective, economical form of heating.

Night storage: from what I've found this seems to be the most cost effectrive option assuming it fits with your lifestyle. New units that are more efficient and controllable should (I hope!) provide a good saving.

Electric radiators: What are the pros/cons of the various types - oil filled, ceramic etc. and are any makes better quality/more reliable than others?

Both: would it be possible to basically use night storage but have an electric radiator (wired into the standard circuit) in the most used room?

Are there any other options I've missed?

Any suggestions would be really appreciated as it seems to be impossible to find unbiased opinions online, just suppliers pushing their own.

Many thanks.

CliveOfIndia

LongtermLandlord said:

Night storage: from what I've found this seems to be the most cost effectrive option assuming it fits with your lifestyle. New units that are more efficient and controllable should (I hope!) provide a good saving.

All electric heating is 100% efficient - that is, 1Kwh of leccy in equals 1Kwh of heat out.  The only difference in terms of cost is if you can make use of cheaper off-peak electricity (Economy 7, Economy 10, whatever it may be) rather than more expensive peak-rate electricity.

In principle, all storage heaters are equally effective, and they still give 100% efficiency.  A newer unit will probably have an advantage in practical terms, since they tend to be better insulated and more controllable - meaning there's more heat available for when you actually need it, and less tends to leak out when you don't want it, up to a point.

LongtermLandlord said:

Electric radiators: What are the pros/cons of the various types - oil filled, ceramic etc.

Again, in terms of efficiency there's no difference, it's just how they release the heat.  At the cheapest end of the spectrum, a fan heater is cheap to buy, gives almost instant heat, and stops giving heat the moment it's switched off.  But they tend to be quite noisy.  An oil-filled rad takes a while to heat up, but continues to give out some heat for a while after it's switched off.  And they're arguably a little bit safer, since there's no moving parts and no exposed (or semi-exposed) elements.  And they make no noise.

If you get one that has a built-in thermostat, this means it's not drawing current constantly - it'll switch itself off and on to maintain whatever temperature you've set.  So if it's switched on for an hour, it might only draw current for 30 minutes (obviously dependent on the size of the room and the temperature).

But ultimately they're all as "efficient" as each other, but some may distribute the heat more "effectively".  And if they're running on peak-rate electricity, they'll be more expensive to run than storage heaters that have got most of their heat from off-peak electricity.

LongtermLandlord said:

Both: would it be possible to basically use night storage but have an electric radiator (wired into the standard circuit) in the most used room?

Absolutely.  In fact a lot of storage heaters do have a "boost" function to give an extra - well, boost - if you need it, but that'll use peak-rate electricity.  Or you could just use any old electric heater either wired or plugged into the ordinary circuit.

You can get infra-red heaters, which can be useful as they heat the person rather than the whole room.  Handy if you're sat watching TV for a couple of hours, but not so practical if you're moving around and want the actual room to be warm.

Aside from all that, what's your insulation like?  You don't want to be paying a fortune for heat, only for a big chunk of it to leak outside.  That's a whole different discussion - e.g. loft insulation is cheap and makes a sizeable difference, so pays for itself in a very short time period.  Double glazing, cavity wall insulation - more expensive to install and a longer pay-back period, but can be worth considering.  Draft excluders on the letter-box and door frames, all sorts of possibilities, but it's always a case of "is it worth spending £x in order to save £y per year ?"

Scot_39

If the NSH are wired on a restricted circuit - something like Snug Octopus - might be far cheaper than E7 or E10.  It offers 6 plus hours overnight plus a 1 hour boost (the FAQ sats in winter only). It was 9p night rate - and the day rate was cheaper than E7 too.

But again with old lossy heaters - it may not be as suited as E10 was - some old NSH are better insulated than others - and you were on E7 for a period so.... .

A full upgrade to ASHP might not be cheap even with grant - as house has no wet radiators.

Reverse per room air conditioning units might work - but will need holes drilled in walls in each room - but they get a similar COP ratio advantage to ASHP tech - so cheaper to run even at day rates.

Electric wall mounted heaters - on current rate electric - range from simple convection panels - to fancy claims for cermaic and other magic dust materials - all at heart are resistive element heaters - 1kW in = 1 kWh out - only the delivery / timing of the heat varies.

Electric heating is expensive - single rate maybe 3x the price ofgas allowing for some gas inefficiency.

NSH are designed to maximise the use of off peak electric - traditionally that is overnight on E7.

E10 if like mine - gives 10 hours - in my case 5 overnight, 3 afternoon, 2 evening - so I run my 25 yr old NSH on lower input (Its a brick core temp regulation not air thermostat like modern NSH and panels I guess) - but they are het back to that level in afternoon and evening - so give out total heat (kWh energy) more smoothly - than say taking the same total charge overnight on E7.

NSH - old ones in particular - are sluggish in their response - they are better for comfort heating - steady - and low if want lower costs.

They arent switch on heat switch off no heat - like the simpest of panels - it can be hours from cold - and thats what they were designed to do - charge overnight - heat all day.  

Ceramic radiators etc have some heat retention - but like NSH you are then heating a core - not the room - to heat the surface - and so again an initial delay - but you get the payback when thermostat kicks in - and they release the heat.

New NSH are more dynamic - HHR like Elnur Ecombi or Dimplex Quantum both come recommended by users here - as far more controllable / thermostatic air temp regulated too. I looked at the level below too - now the top end is approaching £1000 - so things like the Creda TSRE - a couple of £100 less per heater - but still fan assisted and programmable.

A user here @QRizB - did some useful running cost comparisons of different heaters - gas vs single rate vs E7 (as a lot more common than E10 - but E10 is being retrofitted to some old RTS homes now - so might be catching up).

https://forums.moneysavingexpert.com/discussion/comment/78557202/#Comment_78557202

If the old heaters are losing a lot of heat when the tennant doesn't need it - then there are savings to be had by more modern NSH / lot 20 or top end HHR tech.

Dimplex for instance claim savings of upto 27% for their quantum vs older NSH tech and an even higher c47% vs conventional convection / radiator panels only

See the bottom FAQ question "Can Quantum storage heaters save money ?" on

https://www.dimplex.co.uk/products/installed-heating/storage-heaters/quantum

Following that and the posts / previous versions of the post - may help you have a better understanding of the pros / cons of NSH and time shifted rates vs on demand heating systems.

But the bottom line is if you want to heat the room to say same 15-20C profile over 24 hours a day - it will need the same kWh in output energy from any heater.

But more modern heaters are better regulated to achieve that.

(Many wont use NSH in bedrooms as rooms were getting too hot with old lossy panels - heat when not desired / required)

But assuming that profile - with any conventional tech - pretty much the same input energy in kWh - as billed.

NSH help cost by timeshifting cheap rate electric for charging - to all day use.

Old lossy heaters tend to lose heat when not required - especially if out all day say.  So better insulated modern - and ultimately those with High Heat Retention certification - could help many save.  Dimplex iirc quote savings as above - by reducing loss and cheaper rate energy storage.

And the only way to reduce that input energy for the same profile - is to get ASHP style (from ASHP or reverse air con) COP advantage - to reduce the cost - so if a COP of 3 - you only pay for 1/3rd the metered energy.

My gut reaction - is probably the simplest, least disruptive and cost efficient - and hopefully still save £££s for the tennant - is to upgrade the first NSH in say the living room - and see how the tennant gets on with a programmable and thermostatically regulated version of a HHR NSH.

Then think about other rooms - a panel - of only need to heat a bedroom for 1-2 hours per day - might be better for lower running costs.

[But remember as a landlord you want the rooms het sufficiently to avoid damp / structural issues too.]

FreeBear

CliveOfIndia said: Aside from all that, what's your insulation like?  You don't want to be paying a fortune for heat, only for a big chunk of it to leak outside.  That's a whole different discussion - e.g. loft insulation is cheap and makes a sizeable difference, so pays for itself in a very short time period.  Double glazing, cavity wall insulation - more expensive to install and a longer pay-back period, but can be worth considering.  Draft excluders on the letter-box and door frames, all sorts of possibilities, but it's always a case of "is it worth spending £x in order to save £y per year ?"

Loft insulation is cheap and easy to install yourself if reasonably fit. Minimum recommended level is 300mm, but it doesn't hurt to go to 400mm. For the investment, it has the biggest return.

Double glazing is only really worth doing if the old windows are single glazed or you have rotting timber frames - I had ~50 year old aluminium/timber framed with 14mm sealed units. Hinges & seals were failing, and most of the units had blown. Replaced with new low-e uPVC windows & door, and killed most of the cold draughts in the process. Although I'm unlikely to recover the cost via energy savings, it has improved quality of life immensely.

Got cavity wall insulation, and to be honest, can detect no improvement. It is a waste of time and money in my opinion... Internal wall insulation is an alternative - I've done few walls here, and have yet to measure any reduction in heating costs. However, it has reduced condensation on walls to zero, so no mould or peeling wallpaper to contend with. Also have nice smooth walls without any cracks, so a great surface to decorate on to. Even with doing the work myself, I'm not likely to save on heating bills to cover the cost of materials. But it is another "quality of life" investments that is difficult to place a value on.

zxzxzx

Have you considered an A2A system? £1500 for heating/cooling … one unit might work if the property is small enough. Maybe with a heated towel rail in the bathroom. SCOP of 4 so much cheaper to run than any other form of electric heating.
Worth looking at.

LongtermLandlord

Thank you for your feedback. I haven't worked out how to do the quoting thing so here goes ....

CliveOfIndia - The point about all electric heating being 100% efficient and the only way to reduce cost is to use cheaper electricity is well made. 

Newer NSH units being better insulated and more controllable thereby having more heat available when needed is important. I wonder how that compares to an oil filled radiator with built-in thermostat ....? (I will read through the link provided by Scot_39)

I also need to look into the 'boost' function of NSH as, following the first point, that will cost the same as an electric radiator assuming they are as effective at distribution as each other.

and FreeBear - I can't do much more with insulation. It has some loft insulation but is thatched so, according to the EPC man, couldn't do better if I filled the loft! There is mostly secondary double glazing apart from an extension which is double glazed; that wood/glass door is double glazed but maybe a composite door would be better. I'm not sure about the walls but think that will be a step too far for me!

Scot_39 - Snug Octopus seems worth looking into whatever changes I make to the NSH units.

You mention the benefit of ceramic heaters having a thermostat; am I right in thinking that HHR like Elnur Ecombi, Dimplex Quantum or the Creda TSRE you mention also have this thermostatic control?

I haven't yet had time to go through the links you provided but will do so - there's a lot to take in!

Considering your point about NSH and bedrooms, perhaps it might be worth fitting a different form of electric radiator there and your conclusion is certainly worth discussing with my tenant.

zxzxzx - I haven't looked too far into A2A as my initial conclusion was that it needs a lot of 'stuff' (technical term!) to install and it's a small cottage with limited space both inside and out. I'll take another look.

Thank you again, it's great to have some straightforward information not sales talk!

CliveOfIndia

LongtermLandlord said:

Newer NSH units being better insulated and more controllable thereby having more heat available when needed is important. I wonder how that compares to an oil filled radiator with built-in thermostat ....?

The main difference between NSH and oil-filled is that the latter won't store heat (well, not for more than a few minutes).  If, for instance, you work shifts and you actually want the heating on during the night, then an oil-filled rad might actually be a good choice - it's easily controllable, reasonably "instant", and it would be running off cheap-rate electricity (so the same cost as NSH).  But it would be no good if you're thinking of "charging it up" using off-peak electricity in order to use the heat later, they don't work like that - that's the whole point of NSH.

Hope that makes sense !

Scot_39

Yes dimplex and elnur hhr are thermostat regulated.  Both also contain day boost elements if need demands - but both dynamically adjust charge taken to match user demand so shouldn't get caught short.

Sensor on the units so think per room radiator trv rather than central wall thermostat by default.

As are the cheaper non hhr rated level creda and others.

I think hhr and decent lot20 would be fine for bedrooms cf old lossy types - hhr will stay cooler to touch - but both rely on fan to distribute a lot of heat on demand.

Personally I worry about expense of sone fancier radiators and that ceramic heaters (*) are kind of snake oil salesman products - expensive and really caught in between cheap instant response panels and nsh that give you cost savings timeshifted off peak rates that will last all day.  (*) Clouded perhaps in past when likes of Fischer had to settle out of court for the claims their sales reps were making with Leicester trading standards.  A colleagues parents were compensated via that agreement at tge tine as one of original complainants.

Air 2 air as quoted above is I suspect a reference to single room reverse air conditioning units - some of these everything is in the internal wall unit - maybe not to dissimilar in size to large nsh - so just need 2 largish holes drilling for volume air (few inches guess similar to wall air vent for gas appliances) -  some the heat exchanger is in a seperate external unit - so smaller holes for "refrigerent" type pipework - and some of those can do multiple rooms - see examples - of various types - just from top of Google search - not a recommendation - if you've never looked at them in past

https://www.aircondirect.co.uk/ct/air-conditioning/air-conditioners/wall-mounted

Not experienced them in UK - you might need planning permission as they also cool ?

FreeBear

LongtermLandlord said: I can't do much more with insulation. It has some loft insulation but is thatched so, according to the EPC man, couldn't do better if I filled the loft! There is mostly secondary double glazing apart from an extension which is double glazed; that wood/glass door is double glazed but maybe a composite door would be better. I'm not sure about the walls but think that will be a step too far for me!

A thatched roof in good condition will outperform just about any other form of insulation. If you have really thick solid walls, a good chance that they are already thermally efficient so won't benefit from EWI/IWI. Modern materials slapped on the walls would likely be detrimental to the building anyway..

Have memories of visiting a small unheated thatched cottage out in the fens one winter many years ago. Just the heat from half a dozen bodies was enough to get the internal temperature up to a comfortable level quite quickly.

LongtermLandlord

I'm geting there! Seeing how to work out relative costs of peak/off peak vs standard was really helpful, so now it's coming down to heat being 'wasted' during the day when it's not required.

For my current tenant, who is mostly out during the day, this is a waste - but may not be for a future tenant.

Here on MSE it states that with most suppliers you can switch (relatively easily) between tariffs without the need for a meter change; the current supplier is listed. 

So, if I were to fit better end NSH could my tenant switch to a standard tariff and basically run them on boost as and when required, simulating a standard electric heater? This would enable a future tenant to revert back to NSH on a dual tariff if it suited them better.

I'm not sure this a serious option yet, just wondering if it would be detrimental to the NSH units to run them this way.

Scot_39

No idea if would do any real damage - or even if it's really an option - but I personally wouldn't invest in expensive NSH just to run them off of boost.

(I seem to remember the Elnurs had a max setting for how much their automatic mode oversspill boost element could use - not sure if there was a manual limit - I suspect was a bill control thing - rather than a power / lifetime thing.)

Take largest Dimplex QM150RF  - first google retailer - supply only - £950 + your fitting costs.

They only really make - and it's long term - investment sense if can get the payback from offpeak timeshifting.

The day element in that - their largest domestic model - 1.1kW - and its basically then potentially just being used as a very expensive low powered fan heater.

A cheap plug in floor sitting fan heater will get you 2kW output heat for maybe as little as c£20-25

And your not the one paying the bills in any case - so if the current tenant is potentially resistant - then what - at least for now - is the point anyway ?