UKH

I have a gas boiler, which will not be able to be mended next time it breaks down.

I have previously tried to look into air source pump heating, but the suppliers/fitters are few and far between, and are not the easiest to get hold of. So perhaps until the government makes a much bigger effort to bring this sort of technology along, I am perhaps best just getting a gas boiler with the capability for input of hydrogen driven heating later (20%?). That is unless someone can come up with another solution/suggestion. (Will COP in Glasgow make any difference?).

So what boiler manufacturers provide the potential for hydrogen later? (One ponders the safety of such a set up too....).

Rob

How would hydrogen (which goes bang when you set fire to it) be any less safe than natural gas (which, er, goes bang when you set fire to it)?

Just stick an ASHP in, they're not that exotic. Find it hard to believe that you wouldn't be able to secure an installer

https://ecoinstaller.co.uk/home/heating/heat-pumps/

I think the explosive mixture thresholds are worse with hydrogen so you're more likely to blow yourself up. I stand to be corrected though.

A recent webinar at the pipeline industry guild was saying that all gas pipe repairs and new builds are now to hydrogen spec (100%, 20% is a stepping stone,) and that hydrogen spec boilers are to be fitted as well. 

We're just getting a ground source heat pump fitted, RHI are paying us back for most, it should be the same for airsource.

Go ASHP. Start here: https://www.renewableenergyhub.co.uk/main/heat-pumps-information/heat-pump-...

And REAL members here: https://www.recc.org.uk/ - you can search by postcode proximity

Don't forget to register it with the MCS scheme

Hydrogen is also a very small molecule and pipework needs to be of a much better specification than for methane. A couple of extra turns with the PTFE tape just doesn't work.

Happened to see this on Air Source Heat pumps! 

youtube.com/watch?v=GhAKMAcmJFg&

He is Mr Cynic and likes the sound of his own voice and doubtful facts and figures. He could have said it all in about 2 minutes.

In reply to Neil Williams: I remember being shown how hydrogen explodes in Chemistry. It would not be allowed now for health and safety reasons.. Just a small vessel produced a huge explosion. Definitely more dangerous.

So back to my question. Which gas boiler producers are making boilers which have hydrogen input capabilities?

He has an unfortunate delivery and I think the contribution to UK carbon emissions from domestic gas(heating and cooking) is nearer to 15% rather than the 1% he says. However, I have heard that very good insulation is needed for heat pumps to provide enough heat.

I understand the principle of heat pumps but I can't work out if the outside temperature is, say 5C, a air source heat pump can heat the inside of the house to anything higher than 5C.

Dave

Have you noticed that the back of your fridge (or freezer) is warm and the inside is cold?

Now imagine if you made a fridge shaped hole in an outside wall of your house. Put the fridge in the hole with the door on the outside. Rip the door off. Plug the fridge in. Your fridge will now gently heat your house. 
 

Cezza

Our oil boiler broke down at the end of the first lockdown, we replaced it with an ASHP including having all radiators changed. It all took less than a month from breakdown to heat pump up and running. I find it hard to believe you can't find a fitter, sounds like a bit of an excuse not to have an ASHP.

I think the 1% refers to UK as a whole, so 15% of 1% 

For now why not just fit a new condensing boiler (and run it at the recommended temperature) as most will be as hydrogen ready as possible. Whether hydrogen is added to the gas mains or not during its lifetime will at least give you time to consider the alternatives and give you time to consider adding the insulation required to make a ASHP possible unless you already have a hyper insulated house.

What was the cost and the estimated payback period?

I do like the idea of an air source or better ground source heat pump but if my boiler died I'm fairly certain a new gas boiler would be going in. 

If you live in a large modern house with a bit of land around it and a nice south facing suntrap to fill with the equipment then great, but consider the space issues in a 1902 solid stone terrace. Can't put anything out front, wouldn't want to put something out the back as it would either be in the way or annoying the neighbours because it would be close to bedroom windows etc. Haven't really got much spare space indoors that I'd want to sacrifice for a water tank.

Also, if it cost £10k to install, that's 8% of the market value which would never be seen again if I sold it (which I likely will soon) and with the current heating costs I'd be looking at a 30 year payback period.

Compare that to fitting a new gas boiler. Could be done in an afternoon for £1500 apparently. 

His style was a bit annoying and he spoke about "kilowatts of energy" rather than kilowatt hours, but I agreed with most of what he had to say. In particular installing heat pumps in poorly insulated homes will be counterproductive if supplementary heating is required in cold weather when the system efficiency is lower. 

In light of today's climate report, shouldn't we all be going electric, assuming your electric provider is low carbon.

Cost in cash vs cost to environment 

We are on the renewable heat incentive and with that it should pay back over the 7 years.

Ground source wasn't an option where we are, the bore hole for our well is only at 26m which is far from desirable but they couldn't drill any deeper and that is far too shallow for a heat pump.

We live in a 800sqft/75m2 170 year old semi detached stone cottage. The garden is bigger than the average terraced house but not massive. We have the water cylinder and associated equipment outside and built a very well insulated timber lean to around it.

The heat pump is right next to the downstairs bedroom window and is no louder than the oil boiler was, which was in more or less the same spot.

If you have the option of gas then currently your decision making is going to be different to ours as we aren't on mains gas, but long term you might have to consider other factors.

"...> If you have the option of gas then currently your decision making is going to be different to ours as we aren't on mains gas, but long term you might have to consider other factors."

I think part of the equation is that the house is pretty efficient as for as heating goes, and yes we're on gas so it's pretty cheap in general at the moment.

I'm certainly ready for the day when buying a gas boiler will be the choice of the luddite, but I can see that being ~10 years away and hopefully It will be a problem for another person by then.

I'm in a not particularly well insulated old house, with an oil boiler and microbore pipes for the central heating.

I reckon minimum £25 to £30k (plus the disruption of ripping out floors and walls) is what I'd be looking at to go ASHP.

Hydrogen is a hollow promise and a delaying tactic. Like nuclear fusion, it will remain 5-10 years away for the next 30 years, until the boiler manufacturers have bought enough electric heating companies to take over the market. In the mean time, they want people arguing over its safety and its feasibility, installing gas boilers while they await clarity.

Every major boiler manufacturer (Vaillant, Ideal, WB...) currently makes multiple 'Hydrogen-ready' boilers that you can buy today. I promise if you install one you will replace it in 10 years with an electric solution, and it won't have burnt a molecule of hydrogen in its life.

For alternatives, this is shaping up to be an excellent miniseries, although you'll have to wait until episode 6 for the answers you're after: https://www.youtube.com/watch?v=Z7Fvn_kPZcU&t=1s

I also rate https://www.ecobubl.co.uk as technology-agnostic heating engineers committed to low-carbon installs. They'll have some useful ideas more tailored to your needs.

Too much drivel in uk press convincing people that they are expensive or the uk climate is some how too cold for them to work. I think many gas engineers or electricians could make the leap to air and ground sourced installers if they had faith there was a reliable market there. 

I think in the uk it's partially psychology, folk spend a fortune on bathrooms, kitchens, decking, hot tubs, stoves, man caves, conservatories... but heating and insulation has no glitz, nothing to show your neighbours and friends, it largely goes unnoticed until it stops working! So folk won't spend and invest in insulation that will last a lifetime or a heating system that will last longer than any kitchen or bathroom.

Nobody asks about the ROI on a 10/15k kitchen!

The man's talking a load of bollocks. we have an air source heat pump in our early 19th century cottage. We live 900' above sea level so we get extreme weather. it's saved us about £300 per annum on our total fuel bills. (We have no gas). It heats our partially insulated house well and we have great hot water.

£7,000 fitted by a local plumber.

Did you replace an oil boiler? If so what upgrades did you do to radiators/insulation?

No we didn't. We had a barely effective back boiler with an open fire! You have to have double skin radiators because the ASHP runs at a lower temperature than gas or oil or LPG systems.

No they don't, as a kitchen is essentially replacing like for like. Similarly no one asks about payback periods for a replacement gas or oil boiler, as it's something that needs replacing after x number of years anyway, and it's generally going to be more economical, (or at least have identical running costs), than the old one.

However if you're going to install a different system with greater capital expenditure, then there needs to be some payoff in terms of running costs. For example I'm on oil. Big 2500l tank in the garden, big boiler in the utility room, servicing or maintenance results in the homely whiff of kerosene and oil prices fluctuate by significant amounts.

If I could replace it with mains gas then it would be a no-brainer, cheaper to install, cheaper to run. An ASHP would be a similar price to replacing the boiler, but could well result in a cold house and huge ongoing electric bills without retrofitted insulation. It's a big gamble at present.

I'd happily get rid of oil, but it's question of economics, and also what to replace it with. A thermal store might well be a better option, depending on how technology evolves.

Because hydrogen is flammable for a much broader range of air-fuel mixtures than natural gas, has a significantly lower ignition energy, leaks more readily than other gasses and can embrittle metals.

There's good reason it's basically in a class of its own from an industrial safety perspective.

jk

It can.

jk

Indeed. Efficency does drop when it's really cold for a prolonged period, say below -15 or -20c, although decent models will still function up to -30. Either way the uk is perfect for air, water or ground sourced heating. 

As the world's heating up, an air sourced unit that blows air rather than heats piping will work in reverse as AC in the summer and could be powered by solar on the roof. 

Theres a difference between “temperature” and “heat”.

If it's 5C outside and you put a 5kW electric heater outside and switch it for a couple of hours you'll be putting a lot of heat into the environment, but is it going to get hotter than 5C outside? No, it's still going to be 5C, but if you could recover that heat you've just put into the air outside by some means (you could call it an air source heat pump?), you could heat your living room with it.

There's plenty of “heat” to extract at 5C, you just need to pull a lot of 5C air through the heat exchanger.

If you’ve got very ineffective heating , any alternative is going to seem great!  (I imagine you have some sort of woodburner/solid fuel heating as well).  Bisby’s point was moving from a perfectly ok gas boiler system.  

As well as Hydrogen is much more prone to leaking than natural gas as the atoms are a lot smaller than methane molecules.

Try harder. You are talking about spending thousands on a new system, a little bit of extra chasing and legwork is a minimal ask.

Also there are a lot of considerations when thinking about a new central heating system so you should genuinely read into it a bit more or speak to an expert to evaluate the pros and cons of the different solutions available (oil, gas, ground source, air source, wood-burning stove, biomass, etc. etc.)

289 picometres vs 380 picometres if you are going by the kinetic diameter (which you probably should if it's an issue of leakage) - it's only about a 25% difference. I hear this argument a lot and I'm not so convinced by it any more. These guys certainly don't seem to think there is a leakage problem: https://www.osti.gov/pages/servlets/purl/1371474

In fact, they point out that if you did have a leak that caused a fire, a hydrogen fire would actually be less damaging.

Personally, I wouldn't bother with a hydrogen capable boiler as I can't see how they are an improvement from a cost/environmental perspective over pure electric heating. You need electricity to make green hydrogen out of water which you then burn in your boiler reverting it to water. You can't get more energy out than you put it in so why not just use the electricity to heat your house directly? Happy to be corrected if I am missing something but to me it is a red herring probably being kept in the limelight by fossil fuel companies keen to sell hydrogen made from natural gas. Air source, or if possible ground source, heat pumps are the only credible way for most UK houses to get hot water amd heating in a low carbon way that I can see

Surely that depends on the heat output of the hydrogen liberated Vs the heat output that could be produced by the electricity used to liberate that hydrogen?

Probably a completely incorrect analogy, but if I fell and log a tree with a chainsaw I'll get a lot more heat from burning the tree than burning the small quantity of petrol used to run the chainsaw.

You are correct about the efficiencies, but the electric grid can't store any electricity, so if the wind blows during the summer that doesn't help your cold house in December. The alternative is massive battery storage increase in society, but battery manufacture has got a lot of problems already.

Green hydrogen generation is a good storage solution, its relatively very clean in production and usage of the hydrogen and it's quite an efficient process for a newish technology. Where there is remote power generators you don't need to have hundreds of miles of cables being laid to connect them to the grid.

My uncle used to work on ground source heat pump installations.  He told me that the small back garden of my 1910 terraced house was big enough for a GSHP, but the issue would be access for drilling/installation.  Once installed, there's little to see above ground.

The uk needs to start with the basics and insulate, all this government talk about heat pumps, h2... is pointless when the uk standard even for new builds isn't great. End the obsession with double skin brick exterior housing and marginal wall insulation would be a good start.

Most new housing is wooden framed with a single skin of brick these days, isn't it?

I do agree though, the Swiss use concrete with a thick layer of insulating foam and then render over the top.

You can do vertical bore holes for ground source too. 

For terraced housing, way more efficient to have a single large unit supplying the whole street, than each house having and maintaining its own heat pump. There is also no issue trying to get a drilling unit onto the garden of each house.

Same difference, the problem is moisture bricks need ventilation. I think block work interior is still common? 

Not in the UK. Still traditional masonry cavity walls.

It looks as though the new proposed EPC requirements mean insulated cladding will be required for a lot of the older housing stock and commercial properties, which I imagine could cause more problems than gas boiler replacement.  

Both you and someone else up the thread seem to think that I have not bothered, but I spent some quite some time about 15 months ago. The only companies that I could find at that point that may have been able to come and fit me an air-source pump were in the West Country and someone in Derby ( I live in Rutland/Lincolnshire). In both cases I rang multiple times, and never actually got to speak to the "engineer", whom it was determined I needed to speak to, in each case. In fact with one of those firms they apologised for being non-communicative. Based on the poor responses, and the distance, I decided that I did not want to deal with those firms (how would they be if there were problems, when they cannot even respond to a sales interest?).

Wood burning stoves are not good for the respiratory systems of anyone living with them, plus they are gradually being banned. I've looked at Biomass generation.

As regards other comments about insulation, I am planning on gradually going through my house and putting further insulation on the inside of the walls. I've had my cavity wall insulation checked, and it cannot be improved on without sucking it out and starting again, and the removal is more expensive than putting it in in the first place.

Hydrogen usage for heat generates less CO2 than electricity generation in general does at the moment.

Certainly a lot of it is wooden framed.  The estate I used to live in (1990s build) definitely was.

Sure, there are many ways to build a house. And certain developers may favour one method over another. But traditional masonry is still predominantly how new-build houses in the UK are constructed. Scotland will probably have a higher proportion of timber frame.

A decent timber frame house, split layers of insulation in the walls to stop bridging, 150-200mm, 400mm in the roof, triple glazed, with porch / vestibule on entry doors... you'd barely need to heat it in the uk at all. Even less if you make the most of sunlight with big south facing windows. 

A late reply, but there have been some interesting developments on this topic in the last week. It looks like you will be getting blue hydrogen if you do install a hydrogen capable boiler (1) and blue hydrogen looks like it could be as bad if not worse for the environment than natural gas (2). Indeed, what would be the point in using renewable energy to make green hydrogen when you could get a bigger carbon saving by using that green electricity to displace fossil fuel in vehicles or by powering electric heat pumps?

On the energy storage front, while fairly simple, storing hydrogen is not the only option. To me, the most promising looks to be cryogenic storage (3) but there are many other technologies being developed. Therefore, I don't think that each of us is going to have to have energy storage capacity in our own homes although many people are likely to have a car battery that they can drawn down on for the odd period wen there is neither wind not sun.

Blue Hydrogen relies upon carbon capture technology, and the conclusions reached in (3) are based on the assumption that this has been developed and works perfectly at scale. As the paper itself states, this is a very optimistic assumption. I would be more confident in the cryogenic storage technology becoming fully developed and cost effective than I would carbon capture.

Finally, most boilers probably have a maximum lifetime of approx 10-15 years and I can't see there being enough green hydrogen available for widespread use by the early 2030s considering that there is essentially none available at the moment. Therefore, I really can't see the point in buying a hydrogen compatible boiler now, and probably not ever. You're better off starting to save to make the necessary modifications to your house to make it heat pump compatible.

(1) https://www.theguardian.com/environment/2021/aug/17/uk-homes-low-carbon-hyd...

(2) https://onlinelibrary.wiley.com/doi/10.1002/ese3.956

(3) https://highviewpower.com/technology/

Well put. 

I went to a seminar on hydrogen from an investment sector perspective a few weeks back, it's not going to be as simple as sending hydrogen down existing gas mains unfortunately and, as mentioned above, the current 'best' method for producing hydrogen seems overall worse for the environment and scaled up clean production is at least 10 years away.

Stick with a good quality gas condensing boiler or take the plunge into for air source heat pump system - it's a mature and well understood technology with some good installers out there.