Wood pellets or oil, ufh or rads
Discussion
It's almost time to decide on heating for our new build, no mains gas!
The house will be approx 475sqm , average insulation but no where near passive levels
Approx 125mm floor, cavity block walls 100mm xtratherm, 300-400mm in the attic
Will be trying to make as airtight as possible with 3 small kids running in and out.
Walls insulation were already fitted and we only can fit 125mm in the floor or I would have specified more
We seem to have narrowed it down to either a wood pellet boiler to avail of the the 7 year rhi payback or good old oil
Ruled out gshp due to costs and a friend who installed one and doesn't rate it at all
Any thoughts or recommendations appreciated
The house will be approx 475sqm , average insulation but no where near passive levels
Approx 125mm floor, cavity block walls 100mm xtratherm, 300-400mm in the attic
Will be trying to make as airtight as possible with 3 small kids running in and out.
Walls insulation were already fitted and we only can fit 125mm in the floor or I would have specified more
We seem to have narrowed it down to either a wood pellet boiler to avail of the the 7 year rhi payback or good old oil
Ruled out gshp due to costs and a friend who installed one and doesn't rate it at all
Any thoughts or recommendations appreciated
I'd go for oil for a wet heating system. No idea how much wood pellets cost compared to oil, but plenty of oil suppliers in this area, never seen a wood pellet truck?
In a new build, I'd seriously consider electric, as it's unlikely to run out. I had storage heaters in my last house, with the unit in the lounge being an underfloor element buried in a large concrete slab. Not that expensive to run on Economy 7, and pretty much zero maintenance.
Back it up with a multifuel stove.
In a new build, I'd seriously consider electric, as it's unlikely to run out. I had storage heaters in my last house, with the unit in the lounge being an underfloor element buried in a large concrete slab. Not that expensive to run on Economy 7, and pretty much zero maintenance.
Back it up with a multifuel stove.
I think it's a case of preference really.
I looked into the pellet boilers and frankly they seemed a pain - cheap to run BEFORE everyone started wanting pellets - still if you have a lot of room and want something different - go ahead.
I have room but am going with oil.
I have seriously considered UFH but I have never had any issue with rads, they heat up quickly and as the house is empty for 8hrs a day I'm not minded to heat it, nor at night.
I turn my rads on for 15mins and the house is warm - UFH simply can't do this and costs more to install - it really makes little sense unless you live in it 24/7 or are super insulated.
I looked into the pellet boilers and frankly they seemed a pain - cheap to run BEFORE everyone started wanting pellets - still if you have a lot of room and want something different - go ahead.
I have room but am going with oil.
I have seriously considered UFH but I have never had any issue with rads, they heat up quickly and as the house is empty for 8hrs a day I'm not minded to heat it, nor at night.
I turn my rads on for 15mins and the house is warm - UFH simply can't do this and costs more to install - it really makes little sense unless you live in it 24/7 or are super insulated.
clockworks said:
I'd go for oil for a wet heating system. No idea how much wood pellets cost compared to oil, but plenty of oil suppliers in this area, never seen a wood pellet truck?
In a new build, I'd seriously consider electric, as it's unlikely to run out. I had storage heaters in my last house, with the unit in the lounge being an underfloor element buried in a large concrete slab. Not that expensive to run on Economy 7, and pretty much zero maintenance.
Back it up with a multifuel stove.
Pellets are about £210 a tonne blown into a hopper, oil currently dropping. Approx 47p per litreIn a new build, I'd seriously consider electric, as it's unlikely to run out. I had storage heaters in my last house, with the unit in the lounge being an underfloor element buried in a large concrete slab. Not that expensive to run on Economy 7, and pretty much zero maintenance.
Back it up with a multifuel stove.
The rhi for pellets is a big draw , approx £1500 give or take a few hundred quid a year payback, basically free heat for 7 years. Do have access to quite a bit of wood
So many variables out there it's a minefield
I run a company that supplies and installs underfloor heating, it is the superior solution for almost all circumstances. We use exclusively air sourced hot water heat pumps, this being by far the most cost effective way to heat a house in New Zealand.
Yes, even in Christchurch on the South Island the weather is better than the UK - but an air sourced unit still beats oil by a long way. I have converted some houses from oil to a heat pump simply to save money.
Oil is very straightforward, 10 kWhrs in every litre. Hence about 7p/kWhr I believe for the UK. A heat pump can be 3 or 4:1 efficient, so that works out at say 4p/kWhr. (with electricity at 13p a unit).
Note underfloor heating pipes can only go into a concrete slab, and the low temperatures required suit a heat pump really well. Maximum temperature of water going into the floor is 35.
Is the house really 452sqm?
Yes, even in Christchurch on the South Island the weather is better than the UK - but an air sourced unit still beats oil by a long way. I have converted some houses from oil to a heat pump simply to save money.
Oil is very straightforward, 10 kWhrs in every litre. Hence about 7p/kWhr I believe for the UK. A heat pump can be 3 or 4:1 efficient, so that works out at say 4p/kWhr. (with electricity at 13p a unit).
Note underfloor heating pipes can only go into a concrete slab, and the low temperatures required suit a heat pump really well. Maximum temperature of water going into the floor is 35.
Is the house really 452sqm?
Renovation said:
That CAN is my problem - I've looked into heat pumps and everyone makes bold claims but will anyone guarantee a maximum cost / KWHr ?
I looked at all the bold claims as well. Didn't believe them.If it's Fooking cold outside (and you have an air source heat pump)
Then you are going to be mostly using electricity to heat your house.
Sounded expensive to me..............So then the salesman says ahh but you have to average it out over the whole year.
No I say , I only want to heat the house in the winter , when it is cold outside.
We've been mulling this over for the past year or so.
Similar scenario, albeit slightly smaller property at around 330m2. Just about to pick the plumber to carry out the works actually...
We've decided to go with oil (just bought 1000l at 44p/litre), 350-400l thermal store, plus a Multi fuel/wood burning boiler stove (22kw to water). 70m2 of UFH to the extension (as we are having flagstones/tiles and don't want to be walking on cold floors), original part of house and the First Floor to the extension is being heated via radiators.
We already have a boiler (2008 Grant Vortex) - we picked ours up secondhand a couple of years ago for £150!
The way we looked at it was, when we come to resell, it'll be more appealing to have at least two sources of energy; Can't be bothered to light a fire? no problem, switch the oil boiler on. Don't want to use oil? Light the boiler stove (our property does technically have a free supply of wood).
Further down the line we could even incorporate Solar PV for the immersion heater/electrics.
Similar scenario, albeit slightly smaller property at around 330m2. Just about to pick the plumber to carry out the works actually...
We've decided to go with oil (just bought 1000l at 44p/litre), 350-400l thermal store, plus a Multi fuel/wood burning boiler stove (22kw to water). 70m2 of UFH to the extension (as we are having flagstones/tiles and don't want to be walking on cold floors), original part of house and the First Floor to the extension is being heated via radiators.
We already have a boiler (2008 Grant Vortex) - we picked ours up secondhand a couple of years ago for £150!
The way we looked at it was, when we come to resell, it'll be more appealing to have at least two sources of energy; Can't be bothered to light a fire? no problem, switch the oil boiler on. Don't want to use oil? Light the boiler stove (our property does technically have a free supply of wood).
Further down the line we could even incorporate Solar PV for the immersion heater/electrics.
If I was doing this and had the space in the garden, I would go for a GSHP, backed up with a log burner and thermal store, together with some PV panels if they can be hidden away. I don't think oil is the best option in the medium term - it requires storage, access, boilers need lots of servicing, it's expensive, you run out just when you don't want to, people steal it, etc, etc.
My dad has a ASHP and is very happy with it. It has been cheap to run in all weather. It's ugly though!
My dad has a ASHP and is very happy with it. It has been cheap to run in all weather. It's ugly though!
A few posts and everyone with basically a different opinion
This is my trouble, there doesn't seem to be a general consensus on which option to go for
It's probably going to be financially the biggest outlay on the property and I really want to get it right
Oil, pellets, Ashp, gshp, log burner with back boiler
How about ufh or rads? Another thing I don't want to make a mistake on
Think we have decided on rads upstairs, it's just downstairs with about I think 250-270 sqm to cover
Always had rads and like the idea of fast heat on the other hand ufh gives a better feel and apparently is more efficient
But needs to be on for longer periods of time than rads albeit at a lower heat
This is my trouble, there doesn't seem to be a general consensus on which option to go for
It's probably going to be financially the biggest outlay on the property and I really want to get it right
Oil, pellets, Ashp, gshp, log burner with back boiler
How about ufh or rads? Another thing I don't want to make a mistake on
Think we have decided on rads upstairs, it's just downstairs with about I think 250-270 sqm to cover
Always had rads and like the idea of fast heat on the other hand ufh gives a better feel and apparently is more efficient
But needs to be on for longer periods of time than rads albeit at a lower heat
Oil is cheap atm but 60+p/l is more normal.
Renovation said:
That CAN is my problem - I've looked into heat pumps and everyone makes bold claims but will anyone guarantee a maximum cost / KWHr ?
Any heat pump has a performance curve (more a line), the larger the difference you are trying to pump through the lower the efficiency.Underfloor air sourced (hot water) heat pumps are generally quoted at 7/35, 7 degrees ambient and 35 degree water.
I had cause to test one of our units recently, quite a straightforward procedure. Temperature rise, flow rate and current draw. The results were almost identical with the Chinese claims.
Sorry for the formatting, this is a test result page from one our units.
Water Outlet, Ambient Temp, Heating Capacity, Power Consumption, Coefficient of Performance
35 -15 4.64 2.29 2.03
35 -7 5.72 2.34 2.44
35 -2 7.1 2.35 3.02
35 2 8.08 2.39 3.38
35 7 10.36 2.42 4.28
35 15 11.07 2.41 4.59
35 20 11.92 2.41 4.95
50 -15 4.16 3.06 1.36
50 -7 5.14 3.13 1.64
50 -2 6.16 3.14 1.96
50 2 7.63 3.23 2.36
50 7 9.92 3.23 3.07
50 15 10.65 3.23 3.30
50 20 11.03 3.26 3.38
Hence for underfloor, with 35 degree water out, and at -7 ambient, unit is still 2.44:1.
Not forgetting of course underfloor is a form of storage, and heating can be done BEFORE it gets really cold outside (so raising the efficiency).
A lot of people just don't understand heat pumps, and dismiss them "because they don't work when it's cold" etc etc.
With a standard NZ house, heating costs work out about 50p per square metre per month. Use an insulated slab and this can drop to 30p.
Electricity here is around 12p a kWhr - so using an air sourced unit with underfloor heating works out about 3p a kWhr.
Fit a log burner in the main living area in a new UK house, and if the heat pump can't keep up light the fire.
Our 10kW (output) unit, that could just about be run through a UK plug, we charge 3,000 pounds for.
(I lived in the Midlands for 40 years so I know what it's like)
I run a GSHP and UFH and would recommend both strongly.
UFH is the most gentle, comfortable heat you can get and a real pleasure if you like tile or stone floors. I'm bare foot in the house all year round and would use it again for sure.
The GSHP has been installed for about six years and works faultlessly, I don't know how much worse ASHP would be in winter with low air temps??
UFH is the most gentle, comfortable heat you can get and a real pleasure if you like tile or stone floors. I'm bare foot in the house all year round and would use it again for sure.
The GSHP has been installed for about six years and works faultlessly, I don't know how much worse ASHP would be in winter with low air temps??
Go for oil, its cheaper than gas to run, more efficient burn also.
Don't get sucked in by ground source, the numbers don't stack up at all. It/installers/sellers quote an average over the year, which you don't use/need in summer.
I did look at pellet systems myself for the Feed in rates, however they're expensive to look after and not overly reliable yet.
Don't get sucked in by ground source, the numbers don't stack up at all. It/installers/sellers quote an average over the year, which you don't use/need in summer.
I did look at pellet systems myself for the Feed in rates, however they're expensive to look after and not overly reliable yet.
caziques said:
Water Outlet 35
Ambient Temp -2
Heating Capacity 7.1
Power Consumption 2.35
Coefficient of Performance 3.02
Not forgetting of course underfloor is a form of storage, and heating can be done BEFORE it gets really cold outside (so raising the efficiency).
With a standard NZ house, heating costs work out about 50p per square metre per month. Use an insulated slab and this can drop to 30p.
Electricity here is around 12p a kWhr - so using an air sourced unit with underfloor heating works out about 3p a kWhr.
Our 10kW (output) unit, that could just about be run through a UK plug, we charge 3,000 pounds for.
So looking at the above scenario please can you explain exactly what is happening.Ambient Temp -2
Heating Capacity 7.1
Power Consumption 2.35
Coefficient of Performance 3.02
Not forgetting of course underfloor is a form of storage, and heating can be done BEFORE it gets really cold outside (so raising the efficiency).
With a standard NZ house, heating costs work out about 50p per square metre per month. Use an insulated slab and this can drop to 30p.
Electricity here is around 12p a kWhr - so using an air sourced unit with underfloor heating works out about 3p a kWhr.
Our 10kW (output) unit, that could just about be run through a UK plug, we charge 3,000 pounds for.
I presume it means that the max the heater can provide is 35 degrees when it's -2 degrees outside and that takes 2.3KW ?
Heating capacity - is that 7.1 litres of water ?
Coefficient of Performance - does that mean it does it 3x better than an electric kettle ?
Storing heat is a bit misleading - my house is EPC B so easily inside the top 10% if I turn my heating off in winter it is noticeably colder within an hour - within 8 hours it is freezing - yes you could measure that it is warmer than outside only by a couple of degrees.
200m2 house x 0.5 £100 / month PLUS you need a fire for cold days.
I only pay £100 / month in winter for my (mains) gas bill and that can heat my house no matter what the weather and does my hot water too.
Admittedly for my new house, mains gas isn't an option.
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff