meljones35
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We have to decide on a heating system for our cottage. There is nothing at present. No real garden and very close neighbours. Any suggestions?
- Thread starter meljones35
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If you are on mains gas then get a gas boiler. Unless gas prices go up a lot relative to others (unlikely) then this will be the cheapest solution.
If you aren't on mains gas then your options are:
Electric night storage - cheap to install, not particularly cheap to run and you don't get the heat when you want it though E10 is better than E7.
Ground source heat pump - with no land you will need a drill down which adds to the install cost which isn't cheap. Running costs are good though. Works best with a very well insulated house, without this you may not be able to get enough heat into the house to make it warm. Works well with underfloor, doesn't work well with radiators.
Air source heat pump - Not as efficient as a GSHP but still not too expensive to run and cheaper to install.
Oil tank + oil boiler - A bit cheaper to install than GSHP but more expensive to run.
Gas tank + gas boiler - Similar costs to oil to install but you do get tied to a single supplier for your gas which can then get expensive to run.
To make your decision, you will have to cost out each option for your particular requirements. I have a GSHP which is great for us so ask questions on this if you are considering it.
If you aren't on mains gas then your options are:
Electric night storage - cheap to install, not particularly cheap to run and you don't get the heat when you want it though E10 is better than E7.
Ground source heat pump - with no land you will need a drill down which adds to the install cost which isn't cheap. Running costs are good though. Works best with a very well insulated house, without this you may not be able to get enough heat into the house to make it warm. Works well with underfloor, doesn't work well with radiators.
Air source heat pump - Not as efficient as a GSHP but still not too expensive to run and cheaper to install.
Oil tank + oil boiler - A bit cheaper to install than GSHP but more expensive to run.
Gas tank + gas boiler - Similar costs to oil to install but you do get tied to a single supplier for your gas which can then get expensive to run.
To make your decision, you will have to cost out each option for your particular requirements. I have a GSHP which is great for us so ask questions on this if you are considering it.
meljones35
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Thanks for ideas. No gas in village. Do you run underfloor heating or radiators?
meljones35
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Sorry missed your comment on underfloor heating/radiators. Unfortunately the house is poorly insulated at present. I had heard that water temps can be low with GSHP. What problems have you had?
Underfloor downstairs and no heating at all upstairs. This only works if you have good insulation. GSHP works well with underfloor due to low output temp. It is too cool when operating efficiently for radiators.
-- edit - cross post.
With poor insulation, forget GSHP, you can't get enough heat into the floor to compensate for the heat loss unless you make the floor too hot to be comfortable. The only problem we have with the system at the moment is heat loss through the back of the house due to poor insulation which is an issue we are going to fix. Running costs are great and should go down further when we get the insulation sorted.
-- edit - cross post.
With poor insulation, forget GSHP, you can't get enough heat into the floor to compensate for the heat loss unless you make the floor too hot to be comfortable. The only problem we have with the system at the moment is heat loss through the back of the house due to poor insulation which is an issue we are going to fix. Running costs are great and should go down further when we get the insulation sorted.
I have a mix of underfloor and rads with ASHP which works OK but as complicated to get right and is pretty expensive to run - certainly no cheaper than oil.
Bear in mind that the cost of electricity tracks the price of fossil fuels so if oil or gas gets more expensive so does electricity.
I echo the comments about insulation - if you don't make the house efficient then everything will be expensive to run
With GSHP and ASHP it's much better with both to maintain a low flow temp over a large emmiter as this is the most efficient way to run them and it costs substantially more per degree as you get towards the flow temps rads need (about 55C). If you insulate and fit underfloor heating then GSHP is a good combination, ASHP isn't that much worse. You can use oversized radiators but the higher flow temperatures mean greater running costs and you can run out of capacity on ASHP during very cold spells.
However there is an inherent issue with underfloor and smaller rooms. If you have a 2m x 2m room you have 4m2 of heat emitting surface at a maximum temperature of about 35C and say two external walls of 4m length.
If you have a 4m x 4m room you have 16m2 of heat emitting surface - 4 times as much available heating - but only 8m of external wall - only twice as much.
There are some losses into the floor but these don't rise proportionately to area, just to exposed edge and similar things apply to the ceiling losses.
If you want greener heating and can afford it then there are also log boilers (a.k.a wood gasification) and pellet burners. These are comparatively expensive to install but are potentially much greener if you have local supplies for the fuel and they work with radiators which suit smaller rooms and older houses with higher heat demands.
Bear in mind that the cost of electricity tracks the price of fossil fuels so if oil or gas gets more expensive so does electricity.
I echo the comments about insulation - if you don't make the house efficient then everything will be expensive to run
With GSHP and ASHP it's much better with both to maintain a low flow temp over a large emmiter as this is the most efficient way to run them and it costs substantially more per degree as you get towards the flow temps rads need (about 55C). If you insulate and fit underfloor heating then GSHP is a good combination, ASHP isn't that much worse. You can use oversized radiators but the higher flow temperatures mean greater running costs and you can run out of capacity on ASHP during very cold spells.
However there is an inherent issue with underfloor and smaller rooms. If you have a 2m x 2m room you have 4m2 of heat emitting surface at a maximum temperature of about 35C and say two external walls of 4m length.
If you have a 4m x 4m room you have 16m2 of heat emitting surface - 4 times as much available heating - but only 8m of external wall - only twice as much.
There are some losses into the floor but these don't rise proportionately to area, just to exposed edge and similar things apply to the ceiling losses.
If you want greener heating and can afford it then there are also log boilers (a.k.a wood gasification) and pellet burners. These are comparatively expensive to install but are potentially much greener if you have local supplies for the fuel and they work with radiators which suit smaller rooms and older houses with higher heat demands.
childrenanddogs
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AMc said:
We looked in to a wood pellet boiler but I think 'comparatively expensive' may be a bit of an understatement - we were quoted £25k just for the boiler (no plumbing or underfloor heating included).
I'll be following this thread as we are also not on mains gas and scratching our heads as to what to do re: heating. At the moment ground source heat pump, underfloor heating and log burning stoves seem to be winning, but again a ground source heat pump is a fairly big investment, so we may just do a cheap gas boiler (bottled) for now. Tricky one!
worms
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AMc said:
Unfortunately the same probably applies to pellets and increasingly to woodfuel (unless you own your own supply).
GSHP doesn't have to be expensive if you are ok with a bit of work. We self installed ours which was hard work but not particularly difficult. Cost was £5500 including digger hire, underfloor system and everything needed to get it working. Oil would have been about £4500 to get us into the same position and we have already paid back the difference in running costs 2 years later. We did make a bit of mess of the garden though...
skier-hughes
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Our house is poorly insulated on the walls, very old and a bit draughty!
We went for large wood burning stove with back boiler, large dhw tank of 200l inside a water buffer tank of 900l, 50 solar tubes and also connected up the old oil fired rayburn.
Since the nice weather we have lit the fire twice to top up the hot water, yesterday was the second time. Last year we only lit it 3 times from May to September. All our hot water came from the tubes.
In the winter our heating mainly comes from the wood stove, it's rated at 35kw and eats wood, but it has given us a nice warm house every day, even though we were getting temps of -18' outside.
On a bright sunny day we have had the solar tubes providing us with enough heat to gently run the heating, so only having to light the fire as the sun goes down. We do have a large south facing roof.
As we work from home we burn the stove all day in the depths of winter, but this will heat the house and give us 900l of 75' water. We have a timer for the central heating so we get warm house in the monring from the buffer tank of about 3 hours or so, which is plenty, before we relight the stove and off we go again.
Chopping wood is the biggest job with this, but we get all of ours for free, offcuts from a shed/fence maker and trees that fall down into the fields.
Total cost about £15k.
We went for large wood burning stove with back boiler, large dhw tank of 200l inside a water buffer tank of 900l, 50 solar tubes and also connected up the old oil fired rayburn.
Since the nice weather we have lit the fire twice to top up the hot water, yesterday was the second time. Last year we only lit it 3 times from May to September. All our hot water came from the tubes.
In the winter our heating mainly comes from the wood stove, it's rated at 35kw and eats wood, but it has given us a nice warm house every day, even though we were getting temps of -18' outside.
On a bright sunny day we have had the solar tubes providing us with enough heat to gently run the heating, so only having to light the fire as the sun goes down. We do have a large south facing roof.
As we work from home we burn the stove all day in the depths of winter, but this will heat the house and give us 900l of 75' water. We have a timer for the central heating so we get warm house in the monring from the buffer tank of about 3 hours or so, which is plenty, before we relight the stove and off we go again.
Chopping wood is the biggest job with this, but we get all of ours for free, offcuts from a shed/fence maker and trees that fall down into the fields.
Total cost about £15k.
meljones35
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I am following all these ideas with interest. However our outside space is tiny, not enough room for wood pellet store etc, and little sun on the roof. We are going to have a wood-burner in the living room which should heat up that area and above nicely. But the straggling rooms further back will not benefit from this. So need an alternative. Its a tiny cottage with no room for a water tank of any kind. Please keep your ideas coming!
If you're off mains gas and don't have space for a reasonable water tank/thermal store than you're going to struggle with options on most systems.meljones35 said:
GSHP and ASHP won't be able to create instant hot water like a combi boiler can.
ASHP take up little space but they aren't particularly quiet and may cause problems for you and your neighbours (I have 4x16" fans blowing in winter).
GSHP with boreholes works - the bores are expensive to drill and the internal equipment is more bulky than a conventional boiler MdB knows more about that than I do.
If you're prepared to light and maintain fires for hear you might consider a wood burner with a back boiler. I know they can be used to feed radiators but I have no experience of this.
Or you could couple the wood burner with a Mechanical Heat Recovery and Ventilation system (MHRV) this puts air vents into all rooms and uses a low power fan heat exchanger in the loft to warm incoming air with the exhaust - it also distributes warm air from one room into others.
Dick Strawbridge was shown fitting one of these in a period house on teh BBC series "It's not easy being green" that house was exclusively heated with wood burning stoves in 2 rooms IIRC.
However you'll still need to store fuel and heat unit for heat unit I would guess wood pellets are slightly more efficient than logs - so storage may still be a problem.
You also need to factor in that you need a reasonable supply of good wood in case we have another extended cold spell like we saw last winter when your demand goes way up and supply is hard to get.
You may find that an oil fired or LPG combination boiler is the best you can do but if you don't already have a tank you may struggle to site one within the regs.
That would leave you with direct electric heat from convection or fan heaters or electric night storage. You can use point of use electric heaters for hot water in the kitchen and an electric shower.
If you post a general idea of your location in your profile you may get some recommendations for companies to talk to about the options.
One good place to begin would be to get an estimate of how much heat energy you're going to need - from room sizes, window sizes, loft insulation. It would be worth looking at what insulation measures you can practically add as lowering the demand will give you more options.
I've been told bore holes for GSHP are in the £2k to £3k mark but I've no idea if this is accurate. Our heat pump is about the size of a small fridge so not too bad. It does make a bit of noise though and ideally should be kept outside the main house in a garage or similar.AMc said:
I was quoted about £20K for a GSHP with 4 boreholes - the GSHP system was about 6K of that leaving about £14K for the boreholes - this was back in 2007.MdB said:
I was told that the main cost is setup and that once the equipment is on site and the geology is confirmed by the 1st hole then the subsequent ones are cheaper - so the 1st is the most expensive making it more cost effective for larger installs or housing estates etc.
I would hope that the GSHP unit would be in proportion to its output. The only one I've seen is in my pal's demonstration facility and it's the size of a launderette washing machine
Our ASHP indoor units are the size of a gas boiler - the outside units about the size of a large fridge freezer.
A smaller monoblock ASHP would be the size of a small fridge/air con unit with less internal bits to accomodate - still noisy though as you can't blast air past a heat exchanger quietly AFAIK.