Renovating a house - new heating system

niktheguru

Bevarama said:

Hasbeen said:

Bevarama said:

Woah woah, everyone jumping on here and making lots of assumptions.

Yes, gas is more expensive per kWh, but how much kWh does it take to heat a space using Gas CH compared to underfloor heating (UFH)? The price of gas and electric is only half the equation. Yes, 1kWh of electric is 5x the cost of 1kWh of Gas, but how many kWh does UFH use to achieve the same heat level as gas central heating? I am just trying to get a good grip of the numbers as it is likely to be place we live in for the next 20years, I want to get the most efficient system in the long run and not shell out on huge upfront costs blindly.

@Mickey666 - A builder friend quoted that as the cost of connecting it to the mains, based on previous experience in the area. He said it would involve paying the utility company to dig up&repair the road/pavement, the cost of materials, and then the costs of plumbing the supply to the part of the house where the boiler is located.

Have you read the posts? A kWh is a kWh.

Do not see anyone here making assumptions?

You asked a question/advice and received it. 

I did ask for advice indeed, my comment is more about the tone in which people use to convey their information. Some people's response can come across a bit condscending, especially if it is coupled with only a partial answer or not an answer at all.

For example, I don't need someone to tell me a kWh is a kWh, that just states the obvious, and doesn't address the question; which is, generally how many kWh's of electricity are used in UFH for keeping the house a certain temperature, compared to the number of kWh's needed for the same effect with Gas CH. Its a question about efficiency.

Your answer is like: "Me: this car runs on petrol and that car runs on petrol, but which is the most efficient" and your response being "You: well a litre of petrol is a litre of petrol", "Me:.."

To get the answer in the detail that you want you need to give people a bit more information.
Given that you are doing structural work downstairs in an old property we will assume you will be redoing the insulation of the walls and the ceilings to keep heat in. Will you be redoing windows to upgrade to double/triple glazing too?

If considering underfloor heating which one are you thinking of? complete electric underfloor (cheaper to install, like mats on the ground before putting carpet down.....but very expensive to run) or water underfloor heating, which is generally run with gas, and has a higher cost for installation but cheaper to run in long run.

Gas central heating is the tried and tested. Now how efficient and how it heats a room depends on what boiler you get, how many radiatior and what sizes etc etc. The outlay will be higher as you dont have gas at the property, but the running costs over time will be far less. Given that gas unit prices are around 5-6 times lower than electric, it will always win in terms of cost savings.

So it really depends on your purpose....if this is YOUR home for living then I would say gas every time (though worth looking at heat pumps too) as you will avoid massive monthly bills (just look at all the "electric only home" threads in this forum)

If this is a refurb project for "flipping" or selling - you may be able to get away with all electric, as will be cheaper to install but may put off some buyers.....lots of people will not buy electric only homes due to high costs involved (even if the heating is electric underfloor), this is similar to rental properties. People who have no clue will rent an electric only property, but usually its an expensive lesson and the next property they rent will always include gas central heating! either that or they'll sit in the property with 7 sweaters on!

When we redid our house we got electric underfloor heating in the kitchen (and gas everywhere else), and although it is nice to have a warm floor to walk on, after seeing how costly it was having it on, we very rarely use it anymore.

Bevarama

BUFF said:

just to throw another option at you - Green Homes Grant for an Air Source Heat Pump? It won't be the cheapest now but over the long term it may work out as the cheapest.
If the house was built in 1969 hopefully you will be bringing the insulation etc. up to date. 

I haven't even heard of that before.
The idea is that we will bring the entire house up to spec, complete gut and retrofit, including insulation etc. Exploring all options at the moment.

matelodave

Any heat that may be lost travelling through the pipes will usually be inside the house so you'll still get the benefit unless you run the pipes through the loft. However if pipes are run in the loft then they should be insulated so they wont lose a great of of heat. If you really want to start splitting hairs then even a 50% efficiency would only cost you 6p/kwh compared with 13-14p for leccy. Which ever way you cut it leccy is significantly more expensive than mains gas.

BTW we have underfloor heating fed by an air source heat pump because we are all electric. With a decent tariff of 12.25p/kwh (not avaiable anymore) together with a notional COP (efficiency) of say 2.5 still costs me around 5p/kwh.  COP is not as good at this time of the year as it is in the spring, summer and autumn, so it costs more - I'd change it for gas if gas ever became available where I live. Even though its relatively cheap to run, it cost a lot to install and is nowhere near as flexible as gas heating taking hours to respond. It suits us as we are home all day but not so good if we were out all day and wanted a rapid warm up when we got home.

[Deleted User]

Just a passing thought. The Government is phasing out gas boilers for new builds from 2025 and it has set a target of 600,000 heat pump installations a year from 2028.  The CEO of Octopus Energy and others are now suggesting that the 2028 target will not be met without the imposition of a gas Sin Tax. With a blank canvass, I would be looking at future proofing my home. I would thinking about enhanced installation; triple glazing, and a heat pump. 

Hasbeen

Bevarama said:

Hasbeen said:

Bevarama said:

Woah woah, everyone jumping on here and making lots of assumptions.

Yes, gas is more expensive per kWh, but how much kWh does it take to heat a space using Gas CH compared to underfloor heating (UFH)? The price of gas and electric is only half the equation. Yes, 1kWh of electric is 5x the cost of 1kWh of Gas, but how many kWh does UFH use to achieve the same heat level as gas central heating? I am just trying to get a good grip of the numbers as it is likely to be place we live in for the next 20years, I want to get the most efficient system in the long run and not shell out on huge upfront costs blindly.

@Mickey666 - A builder friend quoted that as the cost of connecting it to the mains, based on previous experience in the area. He said it would involve paying the utility company to dig up&repair the road/pavement, the cost of materials, and then the costs of plumbing the supply to the part of the house where the boiler is located.

Have you read the posts? A kWh is a kWh.

Do not see anyone here making assumptions?

You asked a question/advice and received it. 

I did ask for advice indeed, my comment is more about the tone in which people use to convey their information. Some people's response can come across a bit condscending, especially if it is coupled with only a partial answer or not an answer at all.

For example, I don't need someone to tell me a kWh is a kWh, that just states the obvious, and doesn't address the question; which is, generally how many kWh's of electricity are used in UFH for keeping the house a certain temperature, compared to the number of kWh's needed for the same effect with Gas CH. Its a question about efficiency.

Your answer is like: "Me: this car runs on petrol and that car runs on petrol, but which is the most efficient" and your response being "You: well a litre of petrol is a litre of petrol", "Me:.."

You also posted that gas was more expensive.

My post was if it takes 1 kWh of electric to heat a room at 15 pence per hour and approx 1kWh of gas at 3 pence per hour you are using the same amount of kWh.

Mickey666

Agreed - you beat me to the point about radiator pipework losing heat . . . . it doesn't really matter if the heat is lost into the house.  It still contributes to the kWh of heat going into the house, so there's no loss of efficiency.

As for UFH, some people seem to think of it as radically method of heating but in reality it's just another radiator, just a very large one.  And because it's a very large radiator then it can run at a lower temperature but the key thing is that this doesn't make it somehow more efficient because, as mentioned above, if a room needs 20kWh to maintain the required temperature then it needs 20kWh - regardless of the source.  Wall hung traditional radiators have to run hot because of their much smaller surface area, but the calcs are the same - 20kWh from UFH will perform the same as 20kWh from wall-hung rads.

The one big difference with UFH of course is the lag between switching it on and the floor heating up.  But it works both ways because it takes a lot longer to cool down, so it's just a case of adjusting timers accordingly.

So, in a complete renovation project there will be plenty of options.  In my case, I mixed UFH in some rooms with floor-standing cast-iron rads in other rooms, some of which are supplemented with multi-fuel stoves.  But the key reason why my fuel bills for such a large house are sensible is primarily because my fuel costs are basically as low as possible - mains gas and free firewood - and there were no large capital investments needed for things such as heat-pumps or PV panels . . . the numbers for which could not convince me of sensible payback periods.  

Meanwhile, there is one other very good reason, I think, to choose mains gas wherever possible - numbers.  Not numbers as in costs but numbers as in the millions of mains gas installations around the country, domestic and commercial.  Because of that alone, mains gas will receive a great deal of attention from government, industry, manufacturers and basically everyone in the energy business because that's where the biggest market and the biggest requirement for change will be, so that's where the bulk of the R&D will go.  And who knows what might result over the next 20-30 years?

When I started my large renovation project I was full of enthusiasm for 'going green' and envisaged GSHPs, solar PV & thermal, I even investigated short-rotation coppicing to fuel a woodchip boiler (I'm fortunate to have a large paddock) . . . all perfectly sound technologically-feasible options - except the numbers just didn't make financial sense when mains gas was thrown into the mix.

In 20 years time, maybe 10, then I wouldn't be at all surprised if the numbers tell a different story and if I'm still here and need to replace my mains gas boiler with something else then I'll revisit the numbers and take it from there.  But as of today I'd still choose mains gas as my primary energy source.

Tallerdave

@Mickey666 has taken the words out my mouth. UFH is just a massive horizontal radiator but with massive lag on heating up. With top notch insulation though, it's great - heat without a visible heat source is cool (hmmm!).

Direct electric heating is insane but if money is no object, a ground source heat pump would be a future proof alternative to gas. Combine with solar panels and a powerwall to timeshift E7 off-peak power to peak and you'll be sorted.

macman

Does no-one consider the option of a more modern E7 system using Dimplex Quantum NSH's or similar? After mains gas, that may be the next cheapest option to run, and with a much lower capital cost

Gerry1

macman said:

Does no-one consider the option of a more modern E7 system using Dimplex Quantum NSH's or similar? After mains gas, that may be the next cheapest option to run, and with a much lower capital cost

Just for the record, I think you'll find oil and LPG would beat NSHs, although all three are completely pointless when mains gas is available.

Lower running costs, adds value to the property, makes it quicker and easier to sell, gas is simply a no brainer for this property, end of.

macman

I agree, but mains gas is only available at a cost of £2k capital investment to make the connection. That could represent several years (maybe 5 or 6?) worth of savings on actual usage wiped out.

Like you, I'd consider it a worthwhile investment too, but it has to be factored in.