Green Central Heating Boiler/Hydrogen Boiler/Air Source Heat Pump - which one and how

Reed_Richards

Catbells said:

Interesting reading this.  One thing I keep hearing about is 'lower temperatures, bigger radiators'   Sounds logical but initial outlay to replace radiators with bigger ones might be high... 

I think you will find that radiators are relatively cheap compared to the cost of other parts of a new heating system, unless you want fancy "designer" radiators throughout.  And you would benefit from larger surface area radiators whichever heating option you choose.   

Grandad2b

Reed_Richards said:

Catbells said:

Interesting reading this.  One thing I keep hearing about is 'lower temperatures, bigger radiators'   Sounds logical but initial outlay to replace radiators with bigger ones might be high... 

I think you will find that radiators are relatively cheap compared to the cost of other parts of a new heating system, unless you want fancy "designer" radiators throughout.  And you would benefit from larger surface area radiators whichever heating option you choose.   

It's certainly true that you need larger radiators (lower flow temp) to increase efficiency of whatever wet heating system you install. The issue for me is that the whole house would have to be replumbed. To be honest it probably needs doing anyway - the boiler is at least 30 years old - but I can't face the upheaval. It's something, like a rewire, that wants doing before the next owners move in and unless the boiler breaks down we'll leave it until then and take the hit on the selling price.

shinytop

Grandad2b said:

Reed_Richards said:

Catbells said:

Interesting reading this.  One thing I keep hearing about is 'lower temperatures, bigger radiators'   Sounds logical but initial outlay to replace radiators with bigger ones might be high... 

I think you will find that radiators are relatively cheap compared to the cost of other parts of a new heating system, unless you want fancy "designer" radiators throughout.  And you would benefit from larger surface area radiators whichever heating option you choose.   

It's certainly true that you need larger radiators (lower flow temp) to increase efficiency of whatever wet heating system you install. The issue for me is that the whole house would have to be replumbed. To be honest it probably needs doing anyway - the boiler is at least 30 years old - but I can't face the upheaval. It's something, like a rewire, that wants doing before the next owners move in and unless the boiler breaks down we'll leave it until then and take the hit on the selling price.

It's something that will have been considered probably 50 years ago when people were considering ripping up their nice wooden floors and hacking into their walls to install gas CH. It was definitely worth it then; not so much now.   Hopefully today's tradespeople will take more care.  Some houses I've seen look like they've been done with an axe and a lump hammer.

paul991

Employ a carpenter to do lifting of boards making good ect , a few pounds extra but well worth it

oliver1951

It’s a complete minefield. I have had multiple quotes for ASHP now. All the heat loss calcs vary, their assumptions about needed radiator sizes vary and the quantity and placement. I had a great quote from octopus, until it turned out my existing system (gch old 1970’s) is a one pipe system. Then they weren’t interested. I have now accepted a quote but I’m anxious on a number of points. I keep reading about the poor service available for Ashp’s and the cost is horrific. Daikin told me an annual service alone is £200 plus the travel cost for the engineer to come to the house! And I’m not out in the sticks either. Second concern is that rather than electricity getting less expensive relative to gas, the latest figures for The tariffs from July show elec going down by 10% and gas going down by 28%. Thought we wanted to get to net zero. Although I’d prefer to go green (ish) I don’t want to bankrupt myself, ( did that one, no fun) . 3rd concern is my local council tell me I have to get planning permission because it’s going at the front of the house ( only viable location) and that will take 9 months. Quotes last 28 days! Finally the primary time I use heating is nov - mar and the cop in those periods is much lower. Also I’m quite surprised that I’ve been quoted an 8kwh heat pump, which is kind of on the edge. So I’m beginning to wonder whether I should just cancel the contract and stick with my old inefficient but apparently cost effective 1970’s system. Apart from the neg co2 issue, what am I missing?

Meatballs

Reed_Richards said:

Catbells said:

Interesting reading this.  One thing I keep hearing about is 'lower temperatures, bigger radiators'   Sounds logical but initial outlay to replace radiators with bigger ones might be high... 

I think you will find that radiators are relatively cheap compared to the cost of other parts of a new heating system, unless you want fancy "designer" radiators throughout.  And you would benefit from larger surface area radiators whichever heating option you choose.   

Not only fairly cheap but often an easy DIY if you stick to the same width and just go for a taller and thicker (double K2 etc) as no pipework needs to be replaced (assuming no microbore, but sometimes you might go from imperial to metric fittings?). You should double check the heat loss and size appropriately first though.

Screwdriva

I have to agree - it is the wild west out there! That said, here are a 4 constants I have found, regardless of brand/ installer etc.

1) Radiators are relatively inexpensive but only if you have to replace them once. The best radiators are sold by Stelrad. No other brand of radiators lasts as long, according to every single heating engineer I've spoken to. And only oversized K2/ K3 (no others) radiator type will allow sufficient amounts of heat emitted for low temperature heating systems. 

2) The latest crop of heat pumps have the potential to save a small amount of money over every boiler sold. If you have Solar PV and a battery, this is further amplified. How much will always depend on the heat loss of the property, SCOP, and the tariff paid for the amount of energy you purchase. If your home is compatible, I always recommend a heat pump which should cost between £6-7K installed after BUS grant.

3) Heat pumps aren't for everyone. If your installation cost enters the 5 digit range, I would understand the hesitation. This may happen if households have microbore plumbing or totally obsolete radiators etc. In these instances, I recommend a Viessmann 200-W system boiler. It has saved us 31% in gas consumption over our previous 5 year old Worcester Bosch Greenstar boiler. No other boiler comes close. Factor in the tracker gas tariff and the savings have proven incredibly lucrative. For now. 

4) Regardless of which technology you decide on, insulation should remain the priority. External or internal wall installation, 300+mm of loft insulation, triple glazed aluminum windows and underfloor heating reduce property heat loss in isolation and massively in unison. In nearly every scenario, I would prioritize these measures over a new heating source. Not as shiny of a new gizmo I know, but they work wonders!

Bianchiintenso

Just to clarify ASHP and microbore, the systems can and do work perfectly well together. There are 3 houses in our village including ours that have this set up. Initially the system was setup with no antifreeze in and worked perfectly, 2 weeks later the installers came back to add the antifreeze and the ‘gloop’ caused only half the radiator to heat up for a week, before it eventually mixed in completely with the water. I am personally very happy with the system and performance.