Posted by: @editor

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@lucia I’d proceed with the BG quotation. @heacol, who is driving the movement to get rid of buffers in heat pump installations, is now Head of Domestic Heat Pump Design, Net Zero British Gas. I’d be very curious to see how your survey goes and what’s proposed.

I've got Octopus coming to survey next week and BG the week after.  I suspect BG would outsource the installation to a local company which is what they usually do with their other work whereas Octopus use their own in-house trained installers.

Shall report back when I've heard what they have to say.   

Octopus have said they’ll still fit Daikins so I wouldn’t worry on that front.

If you haven’t already, I’d have a listen to Episode 13 & 14 of the Heatio (The Home Energy Podcast) where Octopus talk about the Cosy 6 and also their heat pump installations in general. 

If it wasn’t for @Heacol then I’d be wary of BG but he designed my system so it will be interesting to see what their engineers say.

FWIW my house is very similar to yours in terms of age and insulation and just swapping out for K2’s enabled a 35 C flow temp (we aren’t a bungalow however) but in theory it’s a high temp unit so just because a HT is fitted, it doesn’t have to run that way. 

With the right tariff, even a higher temp system can be affordable to run. Octopus have updated their heat pump tariff (available for any heat pump)

Cosy 11.099p;

04:00-07:00
13:00-16:00
22:00-00:00

Peak Rate (16:00-19:00): 32.843p

Day Rate: 22.65p (for the rest of the day)

Posted by: @dougmlancs

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Octopus have said they’ll still fit Daikins so I wouldn’t worry on that front.

If you haven’t already, I’d have a listen to Episode 13 & 14 of the Heatio (The Home Energy Podcast) where Octopus talk about the Cosy 6 and also their heat pump installations in general. 

I listened to one of them this morning - thank you for the suggestion. Octopus have done a mighty fine brand building exercise and they work incredibly hard at maintaining it. Plus their business strategies are sharp as a razor - market-share bagging and dot-joining. (I'm a customer btw but have not succumbed to the fan club. 😁).  

I'll listen to the next episode on my long motorway drive tomorrow. 

Posted by: @dougmlancs

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If it wasn’t for @Heacol then I’d be wary of BG but he designed my system so it will be interesting to see what their engineers say.

FWIW my house is very similar to yours in terms of age and insulation and just swapping out for K2’s enabled a 35 C flow temp (we aren’t a bungalow however) but in theory it’s a high temp unit so just because a HT is fitted, it doesn’t have to run that way. 

With the right tariff, even a higher temp system can be affordable to run.

I cannot make long term decisions that are tariff-dependant - there's too much market game-playing and crystal ball gazing involved in tariff construction plus Ofgem's nonsense. That doesn't mean I don't play the tariff game myself if I can - I was an early Octopus Tracker person. And I run the Octopus Compare app which maps Agile and Tracker against my energy use. 

Yes, I hope BG can come up with the goods design-wise and not just outsource it to a local heating chump. 

It's good to hear you've managed 35c with K2s - Octopus include some radiator upgrades in the quote but BG don't.

What do ASHP people do in bathrooms rad-wise? I've got a matt-painted flat-panelled towel rail - it will be a shame if it has to go. But I suspect it does.  

@lucia All BG installations are now installed using my open zome, high performing designs. All installations, weather installed by subcontractors, or BG installers are subject to the same internal rigerous auditing, quality and safty checks, as well as random on-site audits. The aim is to keep the quality and perfomance levels of all installations very high. I know the websit and customer jurney currently needs improvement and I am working hard on that. Any critisim will be welcome.

Unfortunatly, in most cases we do have to upfrade bathroon towl rails to radiators to ensure adiquate comfort levels to meet our mandate.

I hope you have a sucessfull heat pump jurney, woever you chose.

We’ve have 2 detailed heat loss surveys now with me insisting that we’re not running at ‘high temperatures’ other than for the dhw legionnaires cycle and no buffers, (just might need a volumiser).

in the bathroom one surveyor added an extra small radiator for both rooms, in the other a 1800mm high towel rail was exchanged for the present 1200mm one. It depends on ease of fitting, how much disruption and what wall space you got. We have constraints on all 3 aspects there.

if you can stand entering all of your house dimensions and guessing your insulation levels then I found playing with heatpunk was very good.

as you know from your reading the worst possible option is a too large Daikin which can’t turn down e.g a 9-10kW (which is really a 16kW) especially if you house only needs ~6kW actually. 
I got addicted to playing around with radiator sizes and where they might go.

I hope it all turns out well!

But having your bills to sanity check the heat loss’s annual usage figures is the most important step.

Posted by: @heacol

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@lucia All BG installations are now installed using my open zome, high performing designs.

Posted by: @heacol

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@lucia All BG installations are now installed using my open zome, high performing designs. All installations, weather installed by subcontractors, or BG installers are subject to the same internal rigerous auditing, quality and safty checks, as well as random on-site audits. The aim is to keep the quality and perfomance levels of all installations very high. I know the websit and customer jurney currently needs improvement and I am working hard on that. Any critisim will be welcome.

Unfortunatly, in most cases we do have to upfrade bathroon towl rails to radiators to ensure adiquate comfort levels to meet our mandate.

 

I hope you have a sucessfull heat pump jurney, woever you chose.

That's really good to hear about installations. Thank you. I'm looking forward to the survey because it will be interesting to understand how the layout of this house affects heat loss. 

I added BG to my list (of 2) because of a fairly in depth YouTube review. 

Posted by: @judith

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We’ve have 2 detailed heat loss surveys now with me insisting that we’re not running at ‘high temperatures’ other than for the dhw legionnaires cycle and no buffers, (just might need a volumiser).

in the bathroom one surveyor added an extra small radiator for both rooms, in the other a 1800mm high towel rail was exchanged for the present 1200mm one. It depends on ease of fitting, how much disruption and what wall space you got. We have constraints on all 3 aspects there.

if you can stand entering all of your house dimensions and guessing your insulation levels then I found playing with heatpunk was very good.

as you know from your reading the worst possible option is a too large Daikin which can’t turn down e.g a 9-10kW (which is really a 16kW) especially if you house only needs ~6kW actually. 
I got addicted to playing around with radiator sizes and where they might go.

I hope it all turns out well!

But having your bills to sanity check the heat loss’s annual usage figures is the most important step.

Thanks for this... Yes, my fear is being told I need something oversized and my finances don't leave me too much room for manoeuvre to pick and choose installers or add loads of K3 radiators to compensate.

I dug out old gas bills from a few years ago when for several reasons the entire house was kept heated throughout from morning to night. So that gives me a clue. 

I will definitely play with heat punk but for now I've stuck with the simple calculations suggested earlier in this thread.  I'm not going to say 'yes' to any installer until I feel ok about the deal anyway. My only worry is if we have a change of government and they axe the BUS funding...  Without that I can't do it and even then it's a stretch. 

I hope any radiator or towel rail changes can be confined to previous pipe work but I guess that may not be possible. I just don't want to re-tile the bathroom. 

It's going to be interesting moving from theories in my head to the reality of installation design.  I have one survey tomorrow and the other next week. I'll update when I get the details but this forum has been so helpful. 

Thanks for this... Yes, my fear is being told I need something oversized and my finances don't leave me too much room for manoeuvre to pick and choose installers or add loads of K3 radiators to compensate.

Murphy's Law....

It's exactly what I didn't expect: the heat loss survey is recommending a 4kw Daikin, 185 litre water tank and almost no radiator changes - my 30/40 year old type 11s are good enough, allegedly. A couple of small ones may get changed for k2s

But I have to wait a couple of weeks for the actual printed survey so maybe there will be some changes. 

I'll try and do my own rough survey next weekend & see if it compares. 

@lucia In this instance it sounds as though Murphy is smiling on you. Assuming HL calculations are correct, it sounds as though you may have a complete system for approximately £500 from Octopus! Regards, Toodles.

Posted by: @toodles

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@lucia In this instance it sounds as though Murphy is smiling on you. Assuming HL calculations are correct, it sounds as though you may have a complete system for approximately £500 from Octopus! Regards, Toodles.

Murphy is not.... at least not yet without some serious haggling. My quote was in the thousands. 🙈

But I had an excellent visit from an installer today who came to check some pipe routing and boiler locating. We talked through my entire spec and he really knows his stuff. I'll write a separate post on the details.