Octopus Heat Pumps

Reed_Richards

Here is the first two lines of a revised calculation:

Room	Heat Loss (W)	Radiator	Output (W)	Coverage	Cost
Bathroom	546	K2 Vert H1800 x L500	808	148
Bedroom 1	570	Stelrad K2 H600 x L1100	876	153	£221.92

So to boost the bedroom output to over 150% coverage you would need a H600 x L1100 K2 radiator instead of a H450 x L900 K2 radiator.  Do you have room to fit a larger radiator like that one?  If so, and the look would be okay, proceed to the next line of the re-calculation.  If not, consider a vertical radiator (but that would be more expensive). 

john-306

MP1995 said:

Spies said:

Money no object, I'd have heat geek come, but I have to consider what I'm paying here and the end result!

Do you have an idea how much more it would be with heat geeks? Is that a saving you can make on running costs for however long you intend to live there?

You can do an online quote on heat geek website.
For me octopus to pay £2800
Heat geek to pay £6200

Heat geek guarantee 3.5 cop at 46c
Octopus tell me 3.48 cop at 50c subject to blah blah blah

stripling

Spies said:

Money no object, I'd have heat geek come, but I have to consider what I'm paying here and the end result!

Folks need to understand that Heat Geek Assured is different from a Heat Geek trained heating engineer. Everyone also needs to understand that Heat Geek is a "brand" not a saint. Plus Heat Geek training is online not practical. There's nothing wrong with that but you want on-the-job experience too. 

Heat Geek Assured gets you a guarantee of sorts but note that British Gas provide similar - a definition of efficiency/capability that they guarantee. You may or may not pay a lot more for this with HG Assured than a HG trained installer may offer. Also, in my area at least 2 of the installers on the local Octopus team are HG trained that I know about. 

Take note, by Adam Chapman's own admission, HG Assured has only done 200 installs nationwide so far. I'm sure they'll get many more but understand the nature of 'Platforms' and 'Branding' and don't be mesmerised by hype.

The independent HG trained (and promoted by HG) installer who I dealt with thinks HG's heat loss software is as clumsy and too 'tick box' as most of the others so he designed his own software in lockdown. 

HG is lucky to have Urban Plumber - a heating 'genius' if ever there was one (check his YouTube channel for useful videos) - promoting their brand but not every HG installer is going to be Urban Plumber. 

Urban Plumber btw has a video online of a heat pump install he did with no radiator changes even though they were little K1s. Not the most efficient on the planet but a lot better than you would think. (The householder was waiting to renovate so he didn't want to change any rads). 

stripling

Copied from an Urban Plumber comment - I'm not saying it is gospel btw but it is echoed by many (except the absolute no buffer purists 😁) and it is a good start for your thought processes.

Good design is:
- calculate or measure property heat loss first and be as accurate as possible
- size the unit for as close to the 100% property load as possible to avoid cycling in the shoulder months
- avoid micro zoning or zoning altogether to extend the system run times - fully weather-compensated systems do not require zoning anyway
- make sure you use proper weather-compensated controls and set them up correctly
- size your emitters or UFH correctly to the room heat loss for even heat distribution - to avoid overheating certain areas - if you have to zone (solar gain)
- use temperature limiters not thermostats - just to close small areas off if needed
- size your pump to the system flow / DT - size your pipework for correct velocity - this is key with heat pumps
- if your system is too large for a single circulator - use buffers, but avoid them if you do not need them as they can create distortion and lower the efficiency of the system
- check you have sufficient system volume for your application - if not add a volumizer - but do not add one if you do not need it - commission the setup correctly checking your flow rates, heat curves, etc...

Reed_Richards

stripling said:

Folks need to understand that Heat Geek Assured is different from a Heat Geek trained heating engineer. Everyone also needs to understand that Heat Geek is a "brand" not a saint. Plus Heat Geek training is online not practical. There's nothing wrong with that but you want on-the-job experience too. 

I love the "brand not a saint" line.  In the past I tried to express similar ideas myself but I never manged to put it so well.  The Heat Geek head-honcho is a strong advocate for heat pumps, which is good if you think heat pumps are a good thing, as I do.  And various people who post here regularly are strong advocates for the Heat Geek brand.  But I have watched some of the Heat Geek videos and come away thinking "well this might be true in some contexts but not as universally true as they give the impression that it is".  

matt_drummer

stripling said:

Copied from an Urban Plumber comment - I'm not saying it is gospel btw but it is echoed by many (except the absolute no buffer purists 😁) and it is a good start for your thought processes.

Good design is:
- calculate or measure property heat loss first and be as accurate as possible
- size the unit for as close to the 100% property load as possible to avoid cycling in the shoulder months
- avoid micro zoning or zoning altogether to extend the system run times - fully weather-compensated systems do not require zoning anyway
- make sure you use proper weather-compensated controls and set them up correctly
- size your emitters or UFH correctly to the room heat loss for even heat distribution - to avoid overheating certain areas - if you have to zone (solar gain)
- use temperature limiters not thermostats - just to close small areas off if needed
- size your pump to the system flow / DT - size your pipework for correct velocity - this is key with heat pumps
- if your system is too large for a single circulator - use buffers, but avoid them if you do not need them as they can create distortion and lower the efficiency of the system
- check you have sufficient system volume for your application - if not add a volumizer - but do not add one if you do not need it - commission the setup correctly checking your flow rates, heat curves, etc...

All great advice and common sense based on common sense, logic and my experience

I would add one really important thing and I am pretty sure he gets this too.

Choose the right heat pump. Each property will have it's own heat loss and you need to get it right. If you get it right, then depending what it is will mean that heat pumps from certain manufacturers won't work so well.

The installer needs to be flexible and prepared to install heat pumps from more than one manufacturer.

This is because the manufacturers build heat pumps in ranges and the badged output isn't a reliable indication of the actual size of the heat pump.

It is all to do with the modulation range, you need to have the full range of modulation which is usually between t about 25% and 100% of the ultimate maximum output.

If you have 8kW of heat loss, install an 8kW heat pump you would think that your heat output would range between 2kW and 8kW, and it does if it is actually an 8kW heat pump.

The trouble is that the manufacturer builds a 16kW heat pump and then limits them to create a range of three or four heat pumps.

So your 8kW heat pump is really a 16kW heat pump that cuts out at 8kW of heat. That's OK except that because it is actually a 16kW heat pump your modulation range is now only 4kW to 8kW, a problem.

All stuff I have said before but I think it is really important. Choose a heat pump that is the biggest in the `range' that matches your heat loss, that way you get the most modulation of heat output.

That may mean a Vaillant is good for me, a Daikin for you and a Mitsubishi for somebody else, all because we have different heat losses.

maf20

If octopus won’t install a heat pump for me, who is the next cheapest/best to them?

I’ve been quoted £4.1k to pay by Octopus. But, they won’t install it on the side of my house and I’m struggling for wall space at ground level

Spies

maf20 said:

If octopus won’t install a heat pump for me, who is the next cheapest/best to them?

I’ve been quoted £4.1k to pay by Octopus. But, they won’t install it on the side of my house and I’m struggling for wall space at ground level

British Gas?

focusonskill

Does the quote from Octopus includes removal of exsisting boiler?
We have an old oil boiler and I'm not sure if they can remove it when installing the heat pump.

Netexporter

I'm fairly certain they will remove an oil boiler but not the oil tank.