I bought a 3 year old one for £250 and had it fitted with a new flue for less than £500 all in.
e.g.
eBay Item
Has anyone got a Air Sourced Heat Pump? If so what are your thoughts?
I am having a extension built and it means moving my 18 year old OIL FIRED combination boiler. 3 plumbers have said its probably on its last legs and
the flue is now unavailable to purchase along with any rubber seals. So if the plumbers damage it getting it out and moving it things are going to be
difficult. A new combi boiler is a whopping £4.5K. A heat pump is huge money (7K - 11K) but the RHI (renewable heat incentive) from the government
makes it a possibility.
Several comments, just talking generally, a heat pump is supposed to give something like 3 to 4 kW out for every kW in, however gas price is generally
roughly half electric cost if you compare kW to KW for the 2 alternatives, so the heat pump SHOULD ( I emphasise should!) be loads cheaper to run.
The price you've been quoted for the gas combi sounds extortionate, I put a Worcester Bosch 24 (can't remeber if thats 24kW or 24,000 btu?)
into a large 4/5 bed property less than a couple of years ago & cost a little over £2k installed, around £2300 IIRC with a 5 year guarantee
I have no idea if the quote for the heat pump sounds expensive or not, nor what you can get back as an incentive, however, another property we own is
ex council & they had a stupid massive central boiler for the whole estate & then piped the hot water everywhere, hardly anyone used it after
a few years cos it was so expensive, but even if you had the system taken out you still get charged an annual fee for the system maintenance (around
£350!), they have finally worked out their system simply doesn't work & now needs massive repairs, so they've employed consultants to
work out best option - they are now installing new electric heat pump boiler & radiator systems in every house which anyone who has bought the
property will subsequently own.With the government incentive, there will be no cost to us & the maintenance charge we currently pay will be
written off in 7 to 8 years, in other words it must be costing around 7.5 x £350 (the maintenance charge) to get these systems installed. Now
obviously this is on a large scale so there will be significant cost savings, but nevertheless that is substantially less than £3k per property &
the owners/tenants will have hugely reduced bills as there is currently no gas on the estate so everything is electrically heated at the moment
without the efficiency of the heat pump system
Sorry, that's a bit long winded, but basically saying I think the heat pump route must be well worth investigating if you are going to be living
there for more than 5 years or so
Be very interested to hear others views on this particularly anyone in the industry
Hi
My mother has Air source heating and my wife works in the renewable industry, there are a few issues to consider
1, renewable heating doesn't work like fuel base heating, the temperatures in the heat exchangers are a lot lower so instead of on/off (on
demand) heating to work effectively the heating is on most of the time maintaining temperature. My mother has found that if you treat the heating
system like a gas system the electricity usage is huge.
2, the radiators need to be very large to be able to effectively exchange the heat from the lower system temperatures.
3, the air sources pump randomly turn on in the middle of the night to either maintain the house or hot water temp, or they start working very early
in the morning to increase temperature to the programmed requirements in the heating controller.
4, the air source heating will work much more effectively if its combine with solar water heating and more efficiently combined with solar PV.
My wife tells me that in the future we'll need to change from single source heat generation and have a combined system, and it wont be one
solution fits all. With electrical PV and storage price set to drop massively in the coming years mirco generation and electric heating will be come
the norm. The electrical companies (DNO's) are already gear up for this with a wiring reg change any time now which require all new house to have
earth electrodes because the electrical network can be relied on to proved sufficient earth with the expected increase in house hold micro generation,
this is partly why the is a 4.5kwh limit on PV systems without DNO approval.
Charlie
I would get a gas boiler but there is no GAS in my village. My only option is a OIL FIRED boiler or Renewable Energy Source.
New oil boiler prices are not cheap however they come up second hand very cheaply and quite often:
I bought a 3 year old one for £250 and had it fitted with a new flue for less than £500 all in.
e.g.
eBay Item
From my experience with renewables in the Housing industry (when the Code for Sustainable Homes was more relevant), Airsource heat pumps were
generally considered the best of the options on paper, if you can find a suitable place to site the equipment, which was often the Achilles heel - and
why most developers went down the PV/Solar or waste water heat recycling and more 'bolt on' options. However the above would always be
backed up by a traditional source of heating.
[Edited on 5-9-17 by loggyboy]
A couple of other points to add to the above.
As has been said the temp from the heat exchanger is lower and therefore a larger surface area of radiator is needed. This is most efficiently
achieved by underfloor heating but special radiators are available.
The RHI payments were very good but did reduce, bizarrely I see they have actually increased again this month. Well worth having.
Most Important - If the house is not particularly well insulated and the ASHP struggles to cope then electricity is used to 'top up'. Single
rate electricity is about twice the price of oil per Kwh. Although you may be able to use dual rate at times eg. immersion on a well insulated hot
water cylinder. Buffer tanks are useful for the heating circuit but need extra space.
I believe the majority of complaints are due to extra electricity used to top up the ASHP. Whilst you are looking at RHI check out the biomass (wood
pellet) rates. Some of the pellet boiler/stoves are worth considering if you have the space.
There are so many variables and it is difficult to get independent advice as each company are trying to promote their own product.
What about a ground source heat pump? A 300 foot hole in the garden with 600 feet of plastic pipe down and up...
I enquired aboit this but we not allowed to go that deep cause there's a 6 foot seam of coal 100 feet down that according to our deeds we not
allowed to extract....
[Edited on 5/9/17 by coozer]
Have a look at wood pellet systems too. my dad installed one that ran his radiators and heated the room it was in.
ASHP and GSHP are good if its fitted into a new build and the build has been designed to use it, ie insulation, rad sizes, UFH all being considered. If it was mine I would be going the LPG route, get calor or a one of there competitors to bury a tank in the garden for free. Most boilers can be converted to LPG easily. Easier, cheaper and more reliable.
Air source heat pumps have to be sized correctly (obvious) most installers dont know how too.
The KW output of the ASHP is only acheived when ambient is 7 degrees, at -4 degrees their output will fall to 50 percent and their efficiency will go
through the floor, so their running cost equals gas, although this is much better than oil, and if you select the output incorrectly your house doesnt
get warm. There was one supplier who used to take 80percent of the heat loss as the size selection - got into a lot of bother.
As others have said their water temp output is only 40-45 degrees a boiler is 85 degrees so. You need radiator sthree times larger to get the same
output. Another poor installer would say the plumber who put the original rads in will have oversized them so they will be ok.
I spent the winter of 2012 when it was minus 12 running round trying to help house owners who had been given poor advice regarding heat pumps.
So would you change from oil to ASHP yes but it only just makes sense.
Would you change fron Gas to ASHP, definately not.
quote:
Originally posted by Irony
I would get a gas boiler but there is no GAS in my village. My only option is a OIL FIRED boiler or Renewable Energy Source.
I'm having a meeting soon with my friend who is a renewables expert so I should get good advice. I'll post up the results. From what I have
read a combination of systems will probably work out to be the most efficient but costly. I.e a Solar setup powering a heat pump with a log burner to
top up when cold. I already have the log burner so it makes sense.
I am currently using on average 1250 litres of oil a year (averaged over the last four years) but I am extending my property by two rooms. At its
cheapest thats a tiny £300 but at its most expensive its a whopping £700. Currently today 1250 litres costs £518 delivered.
It's just the payback period that I am concerned about. I don't mind getting a loan but it has to make financial sense to me.
[Edited on 6/9/17 by Irony]
They are quite a different animal to conventional heating.
Regular heating water is 82 degrees and assuming your room temp is 22 that's a 60 degree difference.
With air to water heat pump, max water temp is 42, a difference of 20, so radiators need to have 3 times the area.
The ones we have have loads of fins throughout.
They operate quite differently too. Rather than issuing water at 82 and turning off when the room is up to temp, the water temp is increased and
decreased based on outside temp and are left to run at very light power for longer periods, so they may have a smaller power level kW.
Typically when outside is
-5, water is 45
+15 water is only 25 degC
Mine does hot water for showers too at about 60 degC
It has its own energy meter to track radiator kWh and shower water kWh and electricity used in kWh
12 months of use has a COP (coefficient of performance) of 2.2. (Not manufacturers figures of 3.5-4.0)
That means for 1 kWh of electricity, I get 2.2 kWh of water heat.
When it gets very cold, heat pumps don't work well and has an internal electric element.
Not sure what uk energy costs are but I pay €0.14 for electricity (24 hours) so I am paying €0.06 kWh for heat, which is the same as natural gas.
I wouldn't spend my own money on the upgrade cost but as it was already fitted to my house, when it needs to be replaced, I'm not sure
I'd spend the higher cost.
quote:
Originally posted by big-vee-twin
Air source heat pumps have to be sized correctly (obvious) most installers dont know how too.
The KW output of the ASHP is only acheived when ambient is 7 degrees, at -4 degrees their output will fall to 50 percent and their efficiency will go through the floor, so their running cost equals gas, although this is much better than oil, and if you select the output incorrectly your house doesnt get warm. There was one supplier who used to take 80percent of the heat loss as the size selection - got into a lot of bother.
As others have said their water temp output is only 40-45 degrees a boiler is 85 degrees so. You need radiator sthree times larger to get the same output. Another poor installer would say the plumber who put the original rads in will have oversized them so they will be ok.
I spent the winter of 2012 when it was minus 12 running round trying to help house owners who had been given poor advice regarding heat pumps.
So would you change from oil to ASHP yes but it only just makes sense.
Would you change fron Gas to ASHP, definately not.
quote:
Originally posted by on_eighty_runner
They are quite a different animal to conventional heating.
Regular heating water is 82 degrees and assuming your room temp is 22 that's a 60 degree difference.
With air to water heat pump, max water temp is 42, a difference of 20, so radiators need to have 3 times the area.
The ones we have have loads of fins throughout.
They operate quite differently too. Rather than issuing water at 82 and turning off when the room is up to temp, the water temp is increased and decreased based on outside temp and are left to run at very light power for longer periods, so they may have a smaller power level kW.
Typically when outside is
-5, water is 45
+15 water is only 25 degC
Mine does hot water for showers too at about 60 degC
It has its own energy meter to track radiator kWh and shower water kWh and electricity used in kWh
12 months of use has a COP (coefficient of performance) of 2.2. (Not manufacturers figures of 3.5-4.0)
That means for 1 kWh of electricity, I get 2.2 kWh of water heat.
When it gets very cold, heat pumps don't work well and has an internal electric element.
Not sure what uk energy costs are but I pay €0.14 for electricity (24 hours) so I am paying €0.06 kWh for heat, which is the same as natural gas.
I wouldn't spend my own money on the upgrade cost but as it was already fitted to my house, when it needs to be replaced, I'm not sure I'd spend the higher cost.
I have done some basic calculations with figures I have obtained from websites and quotes from plumbers. See below.
Renewable Heat Cost
Installation of Heat Pump – 11K (courtesy of which.com)
Installation of Solar Panels – 5K (courtesy of which.com)
Renewable Heat Incentive for Heat Pump & Solar £12414 (over 7 years)
Cost for borrowing 16K from Tesco over 7 years £1734
Electrical Usage extra £100 per year (courtesy of my brain I.e. Total guess)
Here comes the maths
£11000(heat pump) + £5000(solar) - £12414(RHI) + £1734 (loan interest) = £4926 Total Installation Costs over 7 years
£4926 (installation costs) + £700 (extra electricity costs over 7 years) = £5626
Total Installation and Running Costs over 7 years = £5626
Oil Fired Boiler Cost
£4500 installation costs
£300 to 700 per year in oil. We use 1250 litres per year according to boiler juice and today 500 litres costs £518
£518 x 7 years = £3626
Here comes the maths
£4500 + £3626 (oil costs over 7 years) = £8126
Total Installation and Running Costs over 7 years = £8126
This means that going GREEN saves £8126 – 5626 = £2500 over a 7 year period.
I have made a couple of assumptions when doing the above:
1. Cost of Solar Installation according to Which.com is 3K - 5K. So I went with 5K
2. Cost of Heat Pump according to Which.com 7K - 11K. So I went with 11K (I have a quote from a door to door salesmen for £12K
3. I don't believe the solar setup will 100% cover the difference in the extra electricity required by installing the heat pump. I have also
ignored any revenue from a Feed in Tariff that is obtained. I have literally guessed that my electricity bill will go up by £100 per year once the
system is installed. I admit that this is a total guess.
4. I have assumed the price in Oil will stay at todays prices for seven years. Which it obviously won't.
[Edited on 7/9/17 by Irony]
My house uses Consort PLC Panel Heaters as does all my relatives houses. I've had them for over 10 years. Ok so their electric so cost a bit more
to run than gas central heating but -
1) They cost £80 - £100 per panel heater, deliver to your house, fit it yourself with a screw driver
2) Controller cost £80 and you can have one or as many as you want
3) Cost nothing to install, just plug them into the wall
4) Can be moved anytime (handy if you rearrange the furniture)
5) Have no contract costs
6) Have no maintenance costs (apart from replacing two AA batteries every 2 years)
7) Never break down
8) Totally silent
9) Super accurate within 1/2 a degree
10) Fit and forget...completely
Personally I would have nothing else and I've tried just about everything else before
You know the kids even stuck a plastic fork in one and once I got the remains out of it (set off the smoke alarm) I just ran it outside till it burnt
off the rest and put it back on the wall.
[Edited on 7/9/17 by Mr Whippy]
"Ok so they're electric so cost a bit more to run than gas central heating"
Well, roughly double actually if you are looking purely at running costs per kWh! They also aren't going to heat any hot water for you, so a bit
like comparing apples with oranges, there is certainly a place for electric heating, particularly where you have no access to gas & I'm
pretty sure that if you start to add in the capital cost of a gas boiler every 12 - 15 years & the servicing & upkeep of same then gas
doesn't look quite as much better as appears from first glance, but in the long term the gas is going to win hands down, particularly for an
"all in " system that does heating & hot water
As gas isn't available in this instance think Irony's figures make an interesting comparison & you might be pleasantly surprised at the
income from the solar panels, I had mine installed about 4 & 1/2 years ago & get the best FIT, which means I get cheques for a bit over a
grand every year, plus around £200 saving on fuel bills, another couple of years & they'll be showing a profit!
Irony, I'm a bit surprised at the price of your oil bill, £500 odd a year sounds very low, is that doing heating & hot water? as if so
doesn't sound that much different to gas (depending how big the property is of course)
quote:
Originally posted by russbost
"Ok so they're electric so cost a bit more to run than gas central heating"
Russ - what kilowatt is your solar system?
I could add your solar power saving into my equation and it would make it better. However the FIT is not as good these days as it was 4 years ago.
Its about 4 - 5p a KWh I think.
I have worked out my oil usage from the last four years of oil purchases from Boiler Juice. It heats both the hot water and the heating. We
generally keep the house bit colder than most people would keep theirs and the kids bedroom is heated electrically at night. We also have the largest
wood fired stove in the living room that tries its utmost to heat the whole house. I probably have spent £120 a year on wood and coal. Those factors
combined probably lead to a low figure in that department. All the factors however make the renewable option more appealing
[Edited on 7/9/17 by Irony]
4kWh, not that it ever gets to anything like that output apart from about 3 days a year, round here we call that Summer, anyone living North of
Birmingham probably has yet to experience it!
I knew it would never put out as much as it should as we are quite heavily shaded for substantial parts of the day, but knowing we were unlikely to
move for at least 10 - 12 years it was a no brainer for us, I viewed it as an investment.
IIRC we get about 45p (& increasing in line with inflation!) a unit + about 3p a unit for half the output as they assume that's what you put
back in the grid. Ours is purely PV, but some friends who have a large all electric house (no gas) more recently had solar installed & that has an
extra box of tricks which whenever you're not using everything the panels are putting out it tells you you can put an appliance on, do the
hoovering etc. for free assuming you are at home. If you still don't use all available power instead of sending it back to the grid it
automatically heats your hot water so you get a substantial amount of your hot water for free for 3 - 4 months of the summer, all very clever & a
bit tricksy considering you still get the 3p a unit back for half of what you generate irrelevant of the fact that you almost never send anything back
to the grid! They get a lot less per unit than us, around 15p I think, but their installation including the extras was only just over half the cost of
ours. Installation is still gradually getting cheaper, didn't realise the FIT had dropped as low as you say though, worth checking on that as can
make a significant difference
The large wood burner would explain the low oil usage! 
[Edited on 7/9/17 by russbost]
quote:
Originally posted by Irony
System is 12 months only.
I thought the COP was not great but figures quotes are under best conditions.
Energy Prices vary by region.
From my perspective electricity is 14 cent/kWh
With a cop of 2.2 that's 6.5 cent per kWh of water heat.
Night rate would halve this.
Oil here is ca 60 cent/litre and there is 10.5 kWh in each litre.
Loosing 15% in the boiler means 9kwh of water heat per litre or 7 cent/kWh of heated water.
A slight distortion for me is I have a big discount on electricity as a big user. I have an electric car and this adds another 4-5,000 kWh per year.
If I'm honest the biggest saving is the electric car not the heat pump.
Electricity cost me about €4-500 year for 25,000km
Petrol would cost be €2,500
That's ~€2,000 a year for 15,000 miles!
+ tax/maintenance savings.
quote:
Originally posted by on_eighty_runner
They are quite a different animal to conventional heating.
Regular heating water is 82 degrees and assuming your room temp is 22 that's a 60 degree difference.
With air to water heat pump, max water temp is 42, a difference of 20, so radiators need to have 3 times the area.
The ones we have have loads of fins throughout.
They operate quite differently too. Rather than issuing water at 82 and turning off when the room is up to temp, the water temp is increased and decreased based on outside temp and are left to run at very light power for longer periods, so they may have a smaller power level kW.
Typically when outside is
-5, water is 45
+15 water is only 25 degC
Mine does hot water for showers too at about 60 degC
It has its own energy meter to track radiator kWh and shower water kWh and electricity used in kWh
12 months of use has a COP (coefficient of performance) of 2.2. (Not manufacturers figures of 3.5-4.0)
That means for 1 kWh of electricity, I get 2.2 kWh of water heat.
When it gets very cold, heat pumps don't work well and has an internal electric element.
Not sure what uk energy costs are but I pay €0.14 for electricity (24 hours) so I am paying €0.06 kWh for heat, which is the same as natural gas.
I wouldn't spend my own money on the upgrade cost but as it was already fitted to my house, when it needs to be replaced, I'm not sure I'd spend the higher cost.
Interesting figures thank you. Out of interest how old is the system?? The level of the COP is a bit disappointing in a real world scenario