Suggestions for future heating system

[Dee J]

I've been involved in electrical installation around a couple of ASHP installations, and the biggest complexity, cost and potential failure points would seem to be trying to incorporate water heating. For a smaller property with relatively low water usage - one shower + basin and with cold fill dishwasher and washing machine, I wonder whether just a small electrically heated mains pressure tank for the hot water would win in simplicity and capital cost over slightly raised running cost. Save the heat pump for space heating only?
For the OP's larger property I think some analysis of actual usage patterns might help sway the decision. Does the house sit empty 75% of the time or is it continually occupied to capacity? Heat pump operation is generally optimised for continuous steady state rather than fast response operation.

 

[Ozi]

I'm not laughing. But I am smiling People tend to put insulation at the top of the list, which I agree with, but I think joint top are the simple measures such as a jumper etc, etc.

I have thermal long johns and tops, thick socks etc which I wear throughout winter. The house is usually around 16-17c in winter at peak. When it r occasionally reaches 18-20c we start to get hot under the collar and unconformable, even without the thermal layers. Most people naturally acclimatise to their environment; be it levels of heat, hunger, etc. Heat a house well into the 20s, and over the years you'll feel the cold a lot more as your body resets to the new "normal". I totally accept that different people have different tolerances, but at the same time I think the above holds true.

I personally can't understand why how we use energy is often not discussed, or at least left to the margins. So many people have a shower a day (some more!), wash clothes after one or two uses, heat houses to the point they can sit in shorts and t shirts, etc etc. If we hadn't evolved into this era of cleanliness, I think a lot of what is now considered normal would be considered anal OCD type behaviour. We scramble around looking for new innovative ways to make everything greener - which is a great thing - but for me the elephant in the room is our usage.

I feel I must say something on topic now to counter my off topic rant! To the OP, I would be inclined to stick with what you've got for the time being. I think we're in a period of flux and it's hard to know what the future will hold for different energy prices, changing installation prices and grants, new green legislation, and new innovation in heating systems which perhaps haven't surfaced yet.

That's what I meant - you said it better

 

[Jacob]

I'm not laughing. But I am smiling People tend to put insulation at the top of the list, which I agree with, but I think joint top are the simple measures such as a jumper etc, etc.

I have thermal long johns and tops, thick socks etc which I wear throughout winter. The house is usually around 16-17c in winter at peak. When it r occasionally reaches 18-20c we start to get hot under the collar and unconformable, even without the thermal layers. Most people naturally acclimatise to their environment; be it levels of heat, hunger, etc. Heat a house well into the 20s, and over the years you'll feel the cold a lot more as your body resets to the new "normal". I totally accept that different people have different tolerances, but at the same time I think the above holds true.

I personally can't understand why how we use energy is often not discussed, or at least left to the margins. So many people have a shower a day (some more!), wash clothes after one or two uses, heat houses to the point they can sit in shorts and t shirts, etc etc. If we hadn't evolved into this era of cleanliness, I think a lot of what is now considered normal would be considered anal OCD type behaviour. We scramble around looking for new innovative ways to make everything greener - which is a great thing - but for me the elephant in the room is our usage.

I feel I must say something on topic now to counter my off topic rant! To the OP, I would be inclined to stick with what you've got for the time being. I think we're in a period of flux and it's hard to know what the future will hold for different energy prices, changing installation prices and grants, new green legislation, and new innovation in heating systems which perhaps haven't surfaced yet.

Yes I agree, especially about the personal insulation, however unwashed!
The big issue is really two big issues: how to reduce CO2 on the one hand but also how to cope with the climate changes themselves. On the way already, whatever we do in terms of CO2 reduction, unstoppable in the short term and may not be reversible in the long.

 

[Phil Pascoe]

We buy our electricity from an 100% renewable supplier.

So yours won't be going up, then?

 

[nickds1]

So yours won't be going up, then?

Hah! It's currently with Bulb at around 23p /kWh day and 14p/kWh night, but Bulb are a bit shaky and equivalents, like Octopus, are even more expensive. A year ago it was 13p/kWh daytime.

So, using a heat pump that has a COP of around 3.5 (which ours is) that means for every kW we put in from the grid, we get 3.5kW of heat in the house, courtesy of the sun.

Can't ask more, really.

 

[Jameshow]

So yours won't be going up, then?

Must have a separate supply?!!!

 

[Trainee neophyte]

This may not be applicable to the OP directly, but I am a big fan of thermal mass. A current practice around me at the moment is to insulate the outside of your house, thus making the entire structure thermal mass. It makes for a house that doesn't change temperature very much from summer to winter, with only limited heating required. Probably not ideal if you live in a 15th century stately home, but for your average bungalow it might be an option. (The UK habit of having minimal overhanging eaves does mean that the roof may no longer cover the walls after 200mm of insulation is added all around, but in for a penny, in for a new roof?

My other suggestion is for a colossal thermal mass heater. These come in two flavours: masonary heaters like this:

and then you have the hippy - dippy permaculture people who make things out of mud:

They both work on the same principle: heat a monumental amount of stone, cob or similar, (as dense as you can make it), and this then leaks heat out into the house gently over time, much like underfloor heating. Of course it does fill your house up with a huge lump of stuff, but in some circumstances it could work. You can also incorporate it it into the furniture, so you get a heated sofa, if that's what you want. Either way, good luck convincing the interior design department that it is a good idea.

Masonary stove examples

Rocket stove examples

 

[Ozi]

This may not be applicable to the OP directly, but I am a big fan of thermal mass. A current practice around me at the moment is to insulate the outside of your house, thus making the entire structure thermal mass. It makes for a house that doesn't change temperature very much from summer to winter, with only limited heating required. Probably not ideal if you live in a 15th century stately home, but for your average bungalow it might be an option. (The UK habit of having minimal overhanging eaves does mean that the roof may no longer cover the walls after 200mm of insulation is added all around, but in for a penny, in for a new roof?

My other suggestion is for a colossal thermal mass heater. These come in two flavours: masonary heaters like this:

and then you have the hippy - dippy permaculture people who make things out of mud:

They both work on the same principle: heat a monumental amount of stone, cob or similar, (as dense as you can make it), and this then leaks heat out into the house gently over time, much like underfloor heating. Of course it does fill your house up with a huge lump of stuff, but in some circumstances it could work. You can also incorporate it it into the furniture, so you get a heated sofa, if that's what you want. Either way, good luck convincing the interior design department that it is a good idea.

Masonary stove examples

Rocket stove examples

Like the last one. I'm seeing a wife shelf, four cat shelves and me outside chopping wood to keep from freezing my *** off

 

[Jacob]

Thermal mass works brilliantly for the Russian stove Russian stove - Wikipedia where the winter is going to be a lot colder than room temp for a long time, but in temperate zones is less useful - takes extra energy to heat up and then releases it in an uncontrolled way.
Better off with high insulated zero thermal mass so that all energy input goes into heating the air and not the structure

 

[Jacob]

".....Is it worth waiting for an alternative technology to emerge?
Possibly......"

https://www.theguardian.com/money/2...heat-pumps-how-the-costs-and-savings-stack-up

 

[robotmannick]

Thanks all,

What a wealth of interesting replies. I couldn't have hoped for a better response, so thank you everyone for your thoughts.

Insulation in the house is already pretty good - it was a pre-requisite for eligibility of the RHI when I installed the biomass boiler. Sure, there's always ways to improve it, but with diminishing returns. At some point (~5 years?) the windows will need replacing, so that's probably the next upgrade, plus under floor insulation if I'm going to add underfloor heating, though only about 30% of the house is wooden floorboards with a void - the rest is concrete and I don't fancy raising the floor level throughout or digging it up. I do like the idea of external insulation though; there's a 10-12" roof overhang, so enough to add at least 6" I reckon, plus it will cover up the painted bricks that I'm not so fond of and will not shrink the size of the rooms of course. I assume there are ways of fitting it without creating damp problems?

I'm pretty sold on keeping the biomass boiler. Taking it out and selling it will probably raise enough cash to pay someone to take it out, so really not worth the bother - the space it consumes is negligible unless I also take out the thermal store. GSHP is definitely worth getting a proper quote - I agree that the technology is tried and tested so I'm comfortable with the longevity with minimal maintenance. I reckon I'll be ok with the existing radiators - the house is still comfortable even when the thermal store is at 50 degrees or thereabouts.

As for waiting to see what may be around the corner...there's no mains gas here, so mains hydrogen is out of the question. Similarly, community heating would never be installed near me (unless the council decides to approve building 2000 homes in the fields surrounding here...). Maybe there's something else I'm not aware of though.

As expected, there is no clear cut answer and you're right - it's a balance between running cost and initial investment. In general I lean towards paying more up-front to reap the benefits later on, but that has limits.

Thanks again for all the comments and opinions. Great food for thought.

 

[Trainee neophyte]

One more clever wheeze: bit coin mining. You might even make some money out of it...

https://www.prnewswire.com/news-rel...ed-by-bitcoin-301400596.html?tc=eml_cleartime

 

[Sandyn]

So yours won't be going up, then?

and with winter coming, all that wind and rain, the power bills should be going down!!

 

[Sandyn]

You can also incorporate it it into the furniture, so you get a heated sofa, if that's what you want. Either way, good luck convincing the interior design department that it is a good idea.

I would have a rocket mass heater in my house, but there are no regulations for them, so no way to fit just now. They are brilliant.

 

[Jacob]

I'm looking at hibernation as an option. Just get stuck in under a thick fur skin and stay there until spring You Could Probably Hibernate

 

[mikej460]

Thanks all,

What a wealth of interesting replies. I couldn't have hoped for a better response, so thank you everyone for your thoughts.

Insulation in the house is already pretty good - it was a pre-requisite for eligibility of the RHI when I installed the biomass boiler. Sure, there's always ways to improve it, but with diminishing returns. At some point (~5 years?) the windows will need replacing, so that's probably the next upgrade, plus under floor insulation if I'm going to add underfloor heating, though only about 30% of the house is wooden floorboards with a void - the rest is concrete and I don't fancy raising the floor level throughout or digging it up. I do like the idea of external insulation though; there's a 10-12" roof overhang, so enough to add at least 6" I reckon, plus it will cover up the painted bricks that I'm not so fond of and will not shrink the size of the rooms of course. I assume there are ways of fitting it without creating damp problems?

I'm pretty sold on keeping the biomass boiler. Taking it out and selling it will probably raise enough cash to pay someone to take it out, so really not worth the bother - the space it consumes is negligible unless I also take out the thermal store. GSHP is definitely worth getting a proper quote - I agree that the technology is tried and tested so I'm comfortable with the longevity with minimal maintenance. I reckon I'll be ok with the existing radiators - the house is still comfortable even when the thermal store is at 50 degrees or thereabouts.

As for waiting to see what may be around the corner...there's no mains gas here, so mains hydrogen is out of the question. Similarly, community heating would never be installed near me (unless the council decides to approve building 2000 homes in the fields surrounding here...). Maybe there's something else I'm not aware of though.

As expected, there is no clear cut answer and you're right - it's a balance between running cost and initial investment. In general I lean towards paying more up-front to reap the benefits later on, but that has limits.

Thanks again for all the comments and opinions. Great food for thought.

I sold our log boiler system, solar thermal system, Heatrae Sadia, h/w tank and 1500l thermal store for £2.5k on eBay. My buying it was by any measure the worst decision I have made, due to the stress it placed on us maintaining it; yes I under-sized the thermal store but even if I had installed the correct size the stress would not have been worth it. In mitigation I would say that our 18 year old oil boiler had been condemned and the cost of pellet boilers was well outside our budget at the time. Only when cheaper European pellet boilers were introduced into the UK market 6 years ago were we able to sell and switch to an Italian pellet boiler and it has been excellent. We also obtained RHI for it which has paid for our pellets every year. I did get a quote for an ASHP but the size of our house required the largest ASHP available in 2015 and we were quoted over £13.5k compared to the Pellet Boiler system at £7.5k so at the time it was an easy decision.

Our 7 year RHI ends next year so I will look again at a GSHP system to replace it.

 

[Jacob]

I sold our log boiler system, solar thermal system, Heatrae Sadia, h/w tank and 1500l thermal store for £2.5k on eBay. My buying it was by any measure the worst decision I have made, due to the stress it placed on us maintaining it; yes I under-sized the thermal store but even if I had installed the correct size the stress would not have been worth it. In mitigation I would say that our 18 year old oil boiler had been condemned and the cost of pellet boilers was well outside our budget at the time. Only when cheaper European pellet boilers were introduced into the UK market 6 years ago were we able to sell and switch to an Italian pellet boiler and it has been excellent. We also obtained RHI for it which has paid for our pellets every year. I did get a quote for an ASHP but the size of our house required the largest ASHP available in 2015 and we were quoted over £13.5k compared to the Pellet Boiler system at £7.5k so at the time it was an easy decision.

Our 7 year RHI ends next year so I will look again at a GSHP system to replace it.

We were looking at very expensive woodburner/thermal store system with our conversion. Had fantasies about producing enough workshop offcuts to keep it going.
But in reality you need a small wood of your own (1 acre?), wood drying facility, full time labourer/stoker. Madness!
Actually when I am working I do produce a lot of stuff for the normal multi-fuel (Dowling Sumo) - useful but very intermittent.

 

[mikej460]

We were looking at very expensive woodburner/thermal store system with our conversion. Had fantasies about producing enough workshop offcuts to keep it going.
But in reality you need a small wood of your own (1 acre?), wood drying facility, full time labourer/stoker. Madness!
Actually when I am working I do produce a lot of stuff for the normal multi-fuel (Dowling Sumo) - useful but very intermittent.

Yes we were burning a cubic metre a week for 32 weeks a year which all needed stacking and then loading twice a day, which was knackering, especially when it was raining or bitterly cold. I had a plan to build a solar kiln to pre-dry the next winter's logs but when I realised that meant storing 32 IBC crates on our field, all under cover and even then wrapped in plastic to avoid moisture creeping back in, I gave up. We were then at the mercy of log men and constantly let down; even if they could constantly supply seasoned logs their interpretation of 'seasoned' was the tree was cut down 2 years ago but they had only just cut it up ; ironically several local businesses have started up since then with high capacity log kilns.

 

[Phil Pascoe]

Only when cheaper European pellet boilers were introduced into the UK market 6 years ago were we able to sell and switch to an Italian pellet boiler and it has been excellent. We also obtained RHI for it which has paid for our pellets every year...
Our 7 year RHI ends next year so I will look again at a GSHP system to replace it.

Not a dig at you in any way, Mike, but I wonder if when governments plan these subsidies supposedly to save pollution and natural resources they factor in the short lives of the product caused by the subsidies ending? The pollution caused in their manufacture in many cases can't be outweighed by anything saved by their use. It's often tunnel vision virtue signalling.

 

[mikej460]

Not a dig at you in any way, Mike, but I wonder if when governments plan these subsidies supposedly to save pollution and natural resources they factor in the short lives of the product caused by the subsidies ending? The pollution caused in their manufacture in many cases can't be outweighed by anything saved by their use. It's often tunnel vision virtue signalling.

Yes I agree Phil but if I do replace it I will sell the old one. It all depends on the cost of a suitable GSHP. The only issue I have with the pellet boiler is uncertainty on future pellet cost. It cost us £225 pm in 2015 and now it's £300 pm so pretty extortionate albeit only in winter months. One pallet (96kg for £300) lasts from May to September mind you, providing all the HW and the odd chilly night.