Energy Prices (Strictly NO referrals!)

Mercenary Keyboard Warrior said:
Is this based on anything factual or just uninformed scaremongering?

I am seeing feedback from people who actually have ASHP as I follow some for other reasons and they do run pretty much all the time, but are designed to do so

They do a heat deheat cycle every 3 hours from what I saw when it was freezing outside. And as many have said before they are common in countries much colder than the UK
Are they all freezing to death due to their ASHP breaking down.
Gas boilers never wear out or go wrong amirite?
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Yes, they're designed to run all the time, but not at full power. The whole point is to run at lower temperatures and reap the benefit of efficiency. Running at full power they won't be getting near the 300-400% efficiency claimed.

And to @Bug One saying it'll be H2 - no, it won't. It won't ever be hydrogen in homes (or cars). To get hydrogen into homes, you'd have to replace piping and boilers in every home on every branch of a gas main on the same day, as well as possibly some of the gas mains themselves. How on earth do you propose getting around those logistics? Even the 20% blend causes issues as current piping, which is suitable for methane, isn't up to snuff to keep hydrogen from escaping.

That's also on top of the fact that it's incredibly inefficient to produce hydrogen. Even glossing over how cleanly (or uncleanly) hydrogen is made, for every unit of electricity put into the hydrogen making process, you only get around 0.7 units of useable hydrogen out. So you've already wasted 30% of the electricity put in. Then run it through a boiler, where it isn't 100% efficient either. So even if the boiler is 90% efficient, then you're only getting 63% of the energy that was originally available at the start. Instead, that 1 unit of electricity could be sent straight to the home, into ASHP/GSHP which are 300-400% efficient in most circumstances, so get out 3-4 units of heat. Hydrogen is an absolute non-starter.

Finally, ask yourself why Worcester, Bosch, Ideal, all of the boiler makers are bigging-up hydrogen - they aren't making heat pumps. So their business is gone in a few years.
 
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^^ this basically

On top of that, fossil fuel companies are lobbying for it because currently hydrogen is make from steam reformed gas. It’s horrifically carbon intensive.

They push the ‘yeh but we can do carbon capture and storage’ line as part of that lobbying. News flash, carbon capture and storage has never worked and doesn’t seems to be on the cusp of actually working. Likewise where do you store it, most attempts have resulted in it just leaking back into the atmosphere over time. It essentially doesn’t exist at the moment.
 
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squerble said:
Yes, they're designed to run all the time, but not at full power. The whole point is to run at lower temperatures and reap the benefit of efficiency. Running at full power they won't be getting near the 300-400% efficiency claimed.

And to @Bug One saying it'll be H2 - no, it won't. It won't ever be hydrogen in homes (or cars). To get hydrogen into homes, you'd have to replace piping and boilers in every home on every branch of a gas main on the same day, as well as possibly some of the gas mains themselves. How on earth do you propose getting around those logistics? Even the 20% blend causes issues as current piping, which is suitable for methane, isn't up to snuff to keep hydrogen from escaping.

That's also on top of the fact that it's incredibly inefficient to produce hydrogen. Even glossing over how cleanly (or uncleanly) hydrogen is made, for every unit of electricity put into the hydrogen making process, you only get around 0.7 units of useable hydrogen out. So you've already wasted 30% of the electricity put in. Then run it through a boiler, where it isn't 100% efficient either. So even if the boiler is 90% efficient, then you're only getting 63% of the energy that was originally available at the start. Instead, that 1 unit of electricity could be sent straight to the home, into ASHP/GSHP which are 300-400% efficient in most circumstances, so get out 3-4 units of heat. Hydrogen is an absolute non-starter.

Finally, ask yourself why Worcester, Bosch, Ideal, all of the boiler makers are bigging-up hydrogen - they aren't making heat pumps. So their business is gone in a few years.
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So lets try to get a bit real world
My 4 bed detached 2008 build used 52kwh hours of gas for 14 hours of heating and hot water the most usage day in the last cold spell.
Its about 7kwh on average for hot water for us, so 45 for heating.
How is 45kwh of heating over about 14 hours going to stretch a 16kwh heat pump in order to provide 45kwh.
I mean its hardly running flat out 24/7
Its basically needed to run at about 20% capacity, on a day when the temp didn't get above freezing all day.
Now the early part of the day the heating ran practically for an hour, and having tested it specifically earlier in the season I know that heating my house from cold to decent takes about an hour and used about 18h of gas.
So you would expect a 16kwh heat pump to need to run nigh on flat out for maybe 1.5 hours. Then all its needs to do is keep topping up every so often throughout the day.
I think the wear on a gas boiler with the significant impact of heat in short spells is probably more than on the heat pump.
Many boilers have 5 years warranty, more if you pay to service it with an approved heating engineer yes but that heat pump I linked above, 7 years warranty.
They are hardly predicting a significant difference.

Now if you have a house that needs say 150kwh of heating a day its unlikely to be heating thats your issue.
 
Mercenary Keyboard Warrior said:
So lets try to get a bit real world
My 4 bed detached 2008 build used 52kwh hours of gas for 14 hours of heating and hot water the most usage day in the last cold spell.
Its about 7kwh on average for hot water for us, so 45 for heating.
How is 45kwh of heating over about 14 hours going to stretch a 16kwh heat pump in order to provide 45kwh.
I mean its hardly running flat out 24/7
Its basically needed to run at about 20% capacity, on a day when the temp didn't get above freezing all day.
Now the early part of the day the heating ran practically for an hour, and having tested it specifically earlier in the season I know that heating my house from cold to decent takes about an hour and used about 18h of gas.
So you would expect a 16kwh heat pump to need to run nigh on flat out for maybe 1.5 hours. Then all its needs to do is keep topping up every so often throughout the day.
I think the wear on a gas boiler with the significant impact of heat in short spells is probably more than on the heat pump.
Many boilers have 5 years warranty, more if you pay to service it with an approved heating engineer yes but that heat pump I linked above, 7 years warranty.
They are hardly predicting a significant difference.

Now if you have a house that needs say 150kwh of heating a day its unlikely to be heating thats your issue.
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You pointed out there were heat pumps that could run at 65ºC to negate having to switch out radiators, and I was just saying they would be running flat out to keep the temperature at 65ºC. They're much better suited in the 30-40ºC range, and you wouldn't run it in bursts like you've just tried to make an example of, it'd just be running along at extremely low, and extremely efficient power levels.

I don't want a back and forth, I was merely pointing out that just because the heat pump you showed could run at up to 65ºC doesn't mean that it'd be running efficiently at that temperature, nor could it maintain it in colder temperatures, which is what you missed or glossed over.
 
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squerble said:
You pointed out there were heat pumps that could run at 65ºC to negate having to switch out radiators, and I was just saying they would be running flat out to keep the temperature at 65ºC. They're much better suited in the 30-40ºC range, and you wouldn't run it in bursts like you've just tried to make an example of, it'd just be running along at extremely low, and extremely efficient power levels.

I don't want a back and forth, I was merely pointing out that just because the heat pump you showed could run at up to 65ºC that it'd be running efficiently at that temperature, nor could it maintain it in colder temperatures, which is what you missed or glossed over.
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Source? since what you keep saying isnt in line with what people having had them installed say

Heating 10 litres to twice the temp uses twice the energy. The old gsh based couldnt do high temp, not that 65 is even high its just around the max anyone really wants domestically
 
Just to add to the heat pump debate, I'm pretty sure that if you need a 6kw heat pump (or lower), you can get away with 10mm pipework which a lot of existing systems have. I'm pretty sure I stumbled across that nugget during a heat geek video.

For context, when I got a heat pump quote a couple of years ago for my 2003 build 4 bed detached house (its on an estate so not huge), I 'only' needed a 6kw HP. Most of the rads needed changing (10) but the pipework size (10mm) was fine which co-insides with the research I've done since. In the grand scheme of things, 6kw is pretty small for what is a larger than average house in the grand scheme of things.

I ultimately didn't go ahead because it was going to cost £lol and I didn't have solar at the time either. I figured that was the priority and that I could do all of the rad work myself and cut out a big chuck of the cost from the installer (£2k!). 3 of the rads will need to be re-plumbed as I can't just whack a double on as they are already doubles and its a big messy job.
 
Until heat pumps (or am alternative) gets better is just going to have to be gas.

I don't see the switch happening for a long time with a technological revelation
 
I saw an excellent vid, he just setup 4 wind catchers not small but nothing too complicated, durable and cheap and that got a lot of energy for him. Problem for most people might be they arent in the open but I have heard of a village owning a wind turbine collectively.


"Wind in the UK reached a fresh record of 20.9 gigawatts on December 30, and it alone has generated 49 percent of this country's total electricity over the last week."
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silversurfer said:
I saw an excellent vid, he just setup 4 wind catchers not small but nothing too complicated, durable and cheap and that got a lot of energy for him. Problem for most people might be they arent in the open but I have heard of a village owning a wind turbine collectively.




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They popped the record again a couple of days ago, 21.6GW average over a half hour period
 
Mercenary Keyboard Warrior said:
Source? since what you keep saying isnt in line with what people having had them installed say

Heating 10 litres to twice the temp uses twice the energy. The old gsh based couldnt do high temp, not that 65 is even high its just around the max anyone really wants domestically
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OK mate, won't lie - I can't find it. I could have sworn I saw on a YouTube channel (along the lines of Heat Geek, so not just some anti-heat pump loon or anything) that they need their arses run off them to keep the flow up at 65ºC, but I can't find the video or mention, nor find much other supporting evidence, so I'll hold my hands up and say that what I said must be incorrect in this case :) talking of Heat Geek...

I've just been watching a couple of their vids, and using their cheat sheet/rules of thumb, tried to get an idea of heat loss in our house. We're a 2017 build, and HG reckon that as a rough guide, a post-2006 house will lose anywhere between 20-40W per m^2 of floor space. Having just gone wild with a tape measure, and taking the upper bound of 40W loss, our house loses just shy of 3kW with an outside temperature of -3ºC. I also measured our radiators, and using HG's radiator output guide, I end up with a total output of 2.9kW while running at 50ºC mean water temperature.

My EPC does also have the U-values for walls, roof, and floor. From what I can see online, if I take the sum of these and multiply it by the temperature differential of outside to inside, I get a rough fabric heat loss. So me this ends up as 15.41W/m2. I assume any ventilation and window losses would need to be added, but it kinda looks like I'd still be at the lower end of the 20-40W guide from HG, so our heat loss of just about 3kW at -3ºC could actually be lower.

So outside air temp of 10ºC now, means the house at 19ºC is losing a minimum of 6W/m2, so rough floor space of 80m2 (ignoring garage conversion right now due to it not being on central heating) means a heat loss of about 480W. The minimum my boiler can put into the heating system is 7kW :eek: meaning my boiler is around 14x too big for the current weather :eek: :eek: and around 2.5x too big even for an outside temperature of -3ºC.
 
squerble said:
OK mate, won't lie - I can't find it. I could have sworn I saw on a YouTube channel (along the lines of Heat Geek, so not just some anti-heat pump loon or anything) that they need their arses run off them to keep the flow up at 65ºC, but I can't find the video or mention, nor find much other supporting evidence, so I'll hold my hands up and say that what I said must be incorrect in this case :) talking of Heat Geek...

I've just been watching a couple of their vids, and using their cheat sheet/rules of thumb, tried to get an idea of heat loss in our house. We're a 2017 build, and HG reckon that as a rough guide, a post-2006 house will lose anywhere between 20-40W per m^2 of floor space. Having just gone wild with a tape measure, and taking the upper bound of 40W loss, our house loses just shy of 3kW with an outside temperature of -3ºC. I also measured our radiators, and using HG's radiator output guide, I end up with a total output of 2.9kW while running at 50ºC mean water temperature.

My EPC does also have the U-values for walls, roof, and floor. From what I can see online, if I take the sum of these and multiply it by the temperature differential of outside to inside, I get a rough fabric heat loss. So me this ends up as 15.41W/m2. I assume any ventilation and window losses would need to be added, but it kinda looks like I'd still be at the lower end of the 20-40W guide from HG, so our heat loss of just about 3kW at -3ºC could actually be lower.

So outside air temp of 10ºC now, means the house at 19ºC is losing a minimum of 6W/m2, so rough floor space of 80m2 (ignoring garage conversion right now due to it not being on central heating) means a heat loss of about 480W. The minimum my boiler can put into the heating system is 7kW :eek: meaning my boiler is around 14x too big for the current weather :eek: :eek: and around 2.5x too big even for an outside temperature of -3ºC.
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It's one thing to counteract loss, but another thing altogether to actually increase the inside temperature ;)
 
Sinbad2000 said:
It's one thing to counteract loss, but another thing altogether to actually increase the inside temperature ;)
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It's a fair point, but we also lose very little heat :p so the changes in temp in the house barely hit 3ºC with the heating off overnight, so less difference to make up. If we were able to have a heat pump (not sure we could) then leaving the house plodding along at 19ºC all day and setting back to 16/17ºC overnight would mean it'd spend almost all of its life only counteracting heat loss :p
 
squerble said:
OK mate, won't lie - I can't find it. I could have sworn I saw on a YouTube channel (along the lines of Heat Geek, so not just some anti-heat pump loon or anything) that they need their arses run off them to keep the flow up at 65ºC, but I can't find the video or mention, nor find much other supporting evidence, so I'll hold my hands up and say that what I said must be incorrect in this case :) talking of Heat Geek...

I've just been watching a couple of their vids, and using their cheat sheet/rules of thumb, tried to get an idea of heat loss in our house. We're a 2017 build, and HG reckon that as a rough guide, a post-2006 house will lose anywhere between 20-40W per m^2 of floor space. Having just gone wild with a tape measure, and taking the upper bound of 40W loss, our house loses just shy of 3kW with an outside temperature of -3ºC. I also measured our radiators, and using HG's radiator output guide, I end up with a total output of 2.9kW while running at 50ºC mean water temperature.

My EPC does also have the U-values for walls, roof, and floor. From what I can see online, if I take the sum of these and multiply it by the temperature differential of outside to inside, I get a rough fabric heat loss. So me this ends up as 15.41W/m2. I assume any ventilation and window losses would need to be added, but it kinda looks like I'd still be at the lower end of the 20-40W guide from HG, so our heat loss of just about 3kW at -3ºC could actually be lower.

So outside air temp of 10ºC now, means the house at 19ºC is losing a minimum of 6W/m2, so rough floor space of 80m2 (ignoring garage conversion right now due to it not being on central heating) means a heat loss of about 480W. The minimum my boiler can put into the heating system is 7kW :eek: meaning my boiler is around 14x too big for the current weather :eek: :eek: and around 2.5x too big even for an outside temperature of -3ºC.
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Cheers and yeah you see what you put is what seems to be coming out more now.
I think people get hung up on the size etc and try to compare them to gas which is different.
If as you have a recently modern house once up to temp they really don't need that much heating and maintaining that is not hard, and even a relatively small HP will be able to do so.
Of course if you let the temp drop to very cold its going to take some time and effort (for the kit) to get up to temp, but as long as thats rare then its probably not worth over speccing the HP and having one that is not working massively hard but well within its good operating windows.

What you describe with your gas boiler is typical, its why they are constantly firing and going off in a modern house, fire for 5 mins turn off. wait 10-15, fire for 5 mins, turn off. Most things don't like that type of usage, far easier to maintain a lower steady state than on off.
But the boilers cannot run low enough to do that.

BUT if your house is older, I would say maybe mid/early 90s and before chances are the situation is different and you would need a HP that functions more like a gas boiler.

Also if you wanted a HP thats functioning like a combi then its of course also going to have to be a lot more meaty.
On demand hot water is tricky with a good flow.

Its moving on and only going to get better I linked one before but the industrial side is already well over 100 degrees which you never go near in domestic for obvious reasons.
Next 5 - 10 years for most will still be gas boiler replacement IMO unless you specifically want to go HP, maybe having a massive solar, or maybe wind generation.
Wind being a much better match really, but domestic wind generation isn't there really yet either :)
 
Mercenary Keyboard Warrior said:
Also if you wanted a HP thats functioning like a combi then its of course also going to have to be a lot more meaty.
On demand hot water is tricky with a good flow.

Its moving on and only going to get better I linked one before but the industrial side is already well over 100 degrees which you never go near in domestic for obvious reasons.
Next 5 - 10 years for most will still be gas boiler replacement IMO unless you specifically want to go HP, maybe having a massive solar, or maybe wind generation.
Wind being a much better match really, but domestic wind generation isn't there really yet either :)
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On these points - yep! For a HP install here, we'd have to add in a hot water tank with all the associated plumbing, so it'd really add to the cost. We have very small radiators too with 10mm plastic piping to/from the radiators, though the primary piping seems to be 28mm copper.

I think the best we can do in this house is just get a combi boiler that has really low modulation available on it. Our current boiler, once up to temp, only fires in 20-60 second intervals which is giving us between 4-10% efficiency loss. We just need to minimise cycles, really. Luckily, the cycle interval isn't so long (like your example of 5 minutes, off for 10 etc) that it stops the fan and pump so the wear and tear on the fan and pump isn't too much more than normal, it's just the fact the gas valve will be opening and closing quite often to kill the burn.
 
squerble said:
On these points - yep! For a HP install here, we'd have to add in a hot water tank with all the associated plumbing, so it'd really add to the cost. We have very small radiators too with 10mm plastic piping to/from the radiators, though the primary piping seems to be 28mm copper.

I think the best we can do in this house is just get a combi boiler that has really low modulation available on it. Our current boiler, once up to temp, only fires in 20-60 second intervals which is giving us between 4-10% efficiency loss. We just need to minimise cycles, really. Luckily, the cycle interval isn't so long (like your example of 5 minutes, off for 10 etc) that it stops the fan and pump so the wear and tear on the fan and pump isn't too much more than normal, it's just the fact the gas valve will be opening and closing quite often to kill the burn.
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To be honest the 5 mins thing was just kind of a get feel, I haven't paid that much attention to the frequency and timings, just know that its certainly pretty darn frequent I hear the boiler power up so its certainly cycling quite a lot.
Its not 20-60 seconds, but could be just 2-3 minutes.
I guess sensitivity of controls kicks in hard then as well, if the controls are really sensitive and quick to adjust your going to see a far flatter heat and a far more frequent request for a little more.
As the controls become less sensitive the heat request will be less frequent, and will end up needing a bigger boost, with a likely larger overshoot due to the output of the gas boiler.

The other thing is that if you have room it may well be that the other techs, such as hot sand for hot water are far more beneficial than a traditional hot water tank.
They use elec to heat up the sand then water passes through imbedded tubes (literally just 2 plumbing pipes) which heats the water. Whilst you would not benefit from the HP efficiency you would heat them during cheap elec or surplus elec periods
Or maybe even as a boost type arrangement so you can lower the on demand size of the HP needed for water since its going to be topped up by the hot sand box.

So many variables yet to be worked out that are hard to predict. Eg will we really actually have surplus energy of a notable amount on a daily basis to allow lots of cheap off peak energy to be sucked up and stored, or will the demand (via variable pricing) mean its not got that much deviation, and as such efficiency will rule.

It appears to me that the biggest risk will be from poor advice. I mean the equivalent to "everyone is better off with a combi" levels of advice. Because thats always been demonstrably false.
Lets face it many companies will install whats best for them and not necessarily whats best for the consumer.
 
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