Electric house heating - any new tech savvy members?

[Jacob]

How much cheaper is Economy 7? Had a search online but quite difficult to find. Do you pay a higher daytime rate etc?
I guess we all go all electric in the near future as fossil fuel use draws to an end.

 

[Jacob]

.......

• Insulation will reduce operating costs of any system, but how to insulate a lath and plaster, solid granite wall construction. Put on a jumper and turn the thermostat down.

Fitz

Strip off all lath and plaster on inside of external walls and replace with 4" studs with 4" or more Kingspan between. 2" on door/window reveals
That's what we did here. 2000 sq ft top 2 floors of chapel conversion.
My energy bills (gas+electric) currently total £100 per month but expect them to rise.
Wood burner is brilliant and must be saving a bomb - all free scraps, sawdust etc and very rapid warm up - should be top priority for any woodworker.

 

[mikej460]

Insulate insulate insulate ....
Large bore piping with increase efficiency too - insulated if course..

A thermal cylinder like a megaflow will be efficient for water on demand.

Agreed, we have a megaflow and it is excellent. The problem comes when the hot water tap is some distance from the tank resulting in wasted water but also energy lost from the hot water left in the pipe run. It could be argued this heat is dissipated into the house so not such an issue in winter but a waste in summer. There is the law of diminishing returns when contemplating expensive retrofits mind you.

 

[Phil Pascoe]

How much cheaper is Economy 7? Had a search online but quite difficult to find. Do you pay a higher daytime rate etc?
I guess we all go all electric in the near future as fossil fuel use draws to an end.

My night rate atm is 10.5p, day rate 17p. The day rate was a couple of pence ott when I took the contract out. It hasn't gone up yet as I had an 18 month fix. (I dread to think what it'll go up to in August). You need iirc 55%+ of your usage to be at night for it to make economic sense. My meter is set for night to be from 12.30am - 7.30am GMT so it's better in the summer as the night rate lasts til 8.30am so if we do need the tumble drier when the it rains (i.e. most of the summer) the washing gets done overnight then goes in the drier. I expect when Smart meters are universal E7 contracts will disappear anyway, as variable pricing will be the norm.

Without wishing to go down the political rabbit hole, the ever increasing demand for electricity will increase the use of fossil fuels, not end it. Millions of electric cars on dull, still days and all that.

 

[Phil Pascoe]

Incidentally, my only electricity used in heating is the 6" 48w inline fan in the roof. I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom. It works really well and cost less than £200 all in - it also makes the room with the stove more comfortable when the stove is blazing. This is a bungalow, though, not a house.

 

[Jacob]

My night rate atm is 10.5p, day rate 17p. The day rate was a couple of pence ott when I took the contract out. It hasn't gone up yet as I had an 18 month fix. (I dread to think what it'll go up to in August). You need iirc 55%+ of your usage to be at night for it to make economic sense. My meter is set for night to be from 12.30am - 7.30am GMT so it's better in the summer as the night rate lasts til 8.30am so if we do need the tumble drier when the it rains (i.e. most of the summer) the washing gets done overnight then goes in the drier. I expect when Smart meters are universal E7 contracts will disappear anyway, as variable pricing will be the norm.

Without wishing to go down the political rabbit hole, the ever increasing demand for electricity will increase the use of fossil fuels, not end it. Millions of electric cars on dull, still days and all that.

My unit rate a year ago was 14.20p, so not bad compared to yours above.
It's gone up to 18.20p now though.

 

[Jameshow]

Incidentally, my only electricity used in heating is the 6" 48w inline fan in the roof. I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom. It works really well and cost less than £200 all in - it also makes the room with the stove more comfortable when the stove is blazing. This is a bungalow, though, not a house.
View attachment 134697

I fancy doing that between lounge and dining room. How to make in neat in the lounge is the issue for the Mrs!!

 

[Pedronicus]

Incidentally, my only electricity used in heating is the 6" 48w inline fan in the roof. I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom. It works really well and cost less than £200 all in - it also makes the room with the stove more comfortable when the stove is blazing. This is a bungalow, though, not a house.

Wish I'd thought of that 25 odd years ago. We have a AGA in the kitchen which would have nicely heated the bathroom. House is up for sale now so I will mention it to the successful new owners.

 

[Lard]

Incidentally, my only electricity used in heating is the 6" 48w inline fan in the roof. I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom. It works really well and cost less than £200 all in - it also makes the room with the stove more comfortable when the stove is blazing. This is a bungalow, though, not a house.
View attachment 134697

Incidentally, my only electricity used in heating is the 6" 48w inline fan in the roof. I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom. It works really well and cost less than £200 all in - it also makes the room with the stove more comfortable when the stove is blazing. This is a bungalow, though, not a house.
View attachment 134697

i like that idea and have thought about doing it myself for years. Do you ever get the smell from the wood burner in the bathroom or the bedroom?….. in other words is there a risk of dragging in any fumes?

 

[Phil Pascoe]

For anyone thinking to do this, an in line fan is more expensive than a ceiling fan, but is quieter and far more efficient. I had an Xpelair 6" ceiling fan that broke down in a few weeks so replaced it with a Manrose 6" in line one.
It also allows open ends with no grids/meshes, which increases the already much greater throughput.

 

[Phil Pascoe]

I fancy doing that between lounge and dining room. How to make in neat in the lounge is the issue for the Mrs!!

Note the turned wooden "halo".

 

[Jacob]

Kitchen/bathroom etc: If just venting to the outside then zero energy passive vents are brilliant but you need a fairly straight run to somewhere near the roof ridge for them to work.
This is one supplier, there are others. Passivent
We've got one in each of two upstairs bathrooms and they effectively keep the whole building dry and condensation free. No powered fans anywhere.

 

[Lard]

We bought a bungalow with an oil boiler, fitted a wood burning stove and then a heat recovery system that heats a 200ltr cylinder for ‘nothing’ (if you know what I mean). My plumber converted the ‘old’ oil boiler/cylinder/tank system into a pressurised stand-alone unit to enable me to get rid of the attic cylinder/tank. The means that my oil boiler is now used as a backup for central heating only when the wood burner can’t cover it sufficiently.
We have a downstairs internal shower room (ie no external walls so no natural ventilation/windows) and an upstairs en-suite in the attic conversion with no ventilation also. The heat recovery deals with the lot. It’s really good and, although it has a second unused heating coil in the cylinder, it will not take an electric immersion to allow us to use any spare solar output from the panels we had fitted a few years ago.

It was our neighbours who had the solar fitted first (persuading us) and they had the ‘eddi’ system fitted. This provides all of their hot water heating from the solar and if we hadn’t already had the heat recovery I would have had this as well.

My point is that hot water heating does not have to tied into your boiler and so you can manage the central heating and domestic hot water with completely separate systems…..this opens up several ways of achieving it.

 

[Terry - Somerset]

The current cap rate per kwh is electricity 28p and gas 7p. Any on fixed deals will eventually need to move to the cap. What will happen in August when rates are reviewed ???

Electricity is ~3.5 times the cost of gas as no gas boiler works at 100% efficiency. A heat pump with an efficiency of 3.0-4.0 will make the cost of gas vs electricity about equal. Both can be used for heating and hot water - although gas mantles have mostly been made obsolete by LEDs.

Irrespective of heat source, optimising insulation is a given. Second issue which is given little prominence is control - there is no point in keeping rooms warm when not in use.

Energy generation is often confused with how energy is used. Mains supply, PV, turbines, batteries are all ways of generating energy. How best to use it to light and heat the home is another matter.

• Ground source heat pumps - space needed, expensive installation. Low grade heat requiring installation of larger radiators or underfloor heating.
• Air source heat pumps - cheaper than GSHP but it seems with many of the same drawbacks of low grade heat.
• Existing gas and electricity solutions.
• Air conditioning/heating units - low cost installation, can be configured as central compressor with either ducting or separate units in each room. Very controllable.

The last seems to get little attention. It frees up wall space occupied by radiators, installation is straightforward (ducting excepted). Separate solution required for hot water - small gas boiler, immersion heater (use surplus PV??).

For several decades the default solution for homes with a gas supply (77% of dwellings) was gas central heating and hot water. Electricity for lighting and appliances. Those without gas were often smaller flats in urban areas + some rural and more remote properties.

We are a long way from a default today - we are creating an increasingly complex web of solutions:

• energy generation could be PV, gas, mains electric, solar hot water, batteries, turbines
• installation depends on costs, size, lifestyle of occupiers, electric vehicle use, batteries, space, planning constraints etc

Hopefully over the next few years the optimal solution for different property types will emerge.

 

[Lorenzl]

The problem comes when the hot water tap is some distance from the tank

Our boiler at one end of the house and the bathrooms will be in the middle; the furthest radiator 21m from the boiler. It is a long narrow house.

Wood burner is brilliant and must be saving a bomb

There is a wood burner in the lounge; again at one end of the house. The other end has a fireplace so we might add another wood burner there.

Agreed, we have a megaflow and it is excellent.

We currently have one and it is quite larger but I was thinking about the thermal battery to replace it.

I have very well insulated 6" ducting from the living room where the stove is to the bedroom and bathroom.

A friend converted a barn years ago and had a full height lobby. He decided to put a bathroom fan near the apex of the roof ducted down to floor level. He said it wasn't worth the effort.

My night rate atm is 10.5p, day rate 17p.

I had a look at the rates the other day and it was ~£0.09 economy 7 and ~£0.20 peak and was only £0.16 all day. I don't think electrical companies loose out.

We've got one in each of two upstairs bathrooms and they effectively keep the whole building dry and condensation free. No powered fans anywhere.

Interesting but I am not sure I want a vent sticking out of the roof. I couldn't actually find anything interesting on that site and will ask my friend Google about it later.

there is no point in keeping rooms warm when not in use.

I am finally getting my wife to understand that. All I have to do next is to get her to close doors!

A lot of our decisions are really form over function. Heating water for rads from electricity is inefficient and I should use for example IR panels everywhere. I suppose I could install rads for their appearance and still have IR panels but would need to hide the panels so they probably wont be as efficient. We could cover the whole roof of the house and garage in solar panels but don't want to. The boiler will be in the kitchen if we have one and would probably be hidden in a cupboard but in fact can go anywhere as no flue. If I do go down the thermal battery route they can go anywhere in the house and can again be hidden as they don't need access to an outside wall for a flue.

Ground source heat pumps look a better option but need a lot of room unless you use a bore hole.

 

[mikej460]

Ground source heat pumps look a better option but need a lot of room unless you use a bore hole.

And a lot of money..

 

[Lorenzl]

I suppose with insulation and heating you have to decide where to draw the line. This is not a new house and so I don't need to meet any regulations and I may not stay that long. The longest I have lived in one house is 12 years. I could put the minimum insulation in or none and just pay the for the heating

 

[Sideways]

I'll not try to justify this on grounds of money saving - it feels more like a prepayment plan - but we have a large roof and I've just had 9kW of solar panels fitted. It's April, and we're making 20 to 40kWh a day. I expect that peak production in summer may get as high as 50kWh a day. I've put in an Eddi unit hooked up to the immersion and a week ago, I turned off the gas boiler schedule for the hot water tank as the surplus solar is giving us 150- 200 litres of 75C water each day.

One Eddi unit can only handle 3.6kW of what can be several kW of PV but it adds up over the day.
We're happy with the output from the panels and the fact that they generate even on pretty dull days (the reason for installing so many) but I think that the large battery we have on order will be essential to even out the very variable solar energy so that we can use it.

 

[Jameshow]

Our house is a former bungalow with I guess no cavity wall insulation nor roof insulation both if which are hard to get too. However the ground floor is fully accessable via a shallow cellar would you use 50mm or 100mm celotex?

Cavity wall insulation would be the next stage, can it be blown into rafter spaces between plasterboard and the roofing felt.

 

[Lorenzl]

I have just remembered a youtube video from years ago where a guy made a warm air heater from beer cans. There are quite a few examples on youtube now.