Posted by: @editor

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Posted by: @jamespa

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I had exactly the same experience, 2x+ oversizing (16kW 'surveyed' vs 7kW measured).

I just don’t understand how this is still happening and this problem is not going away. Our local heating engineer (who will be working on our system soon) stopped by for a quick chat and coffee yesterday.

He’s just won a new ground source heat pump project on a large new build nearing completion, 450sqm with a heat loss around 13. The homeowner, he says, is disengaged and not asking any questions, and the proposal they nearly accepted was for a cascade system with 2 x 12kW units. 

In fairness my experience was 2 years ago.  However the example you quote and that of @simonb seems to confirm it is still happening.  

The change to the calculation methodology which was mandatory from mid last year should have dealt with the ACH problem at least to an extent, assuming of course that installers have updated their methodologies.  However it wouldn't do anything for the problem of ignoring fabric upgrades (GIGO!) and possibly not for double counting.  As you say there still appear to be some ludicrous numbers out there, so ludicrous that a bit of elementary sense checking would easily spot them.

I’m new to your very useful forum, and I’m looking for a top installer in Norfolk. Does anyone have experience of R A Brown Heating?

@silver-fox I am familiar with the team at RA Brown and have spoken to them many times. They come across as being very professional, but I have no homeowner feedback to vouch for the quality of their work. Sorry I can't be of more assistance than that.

PS – thank you for buying a copy of The Ultimate Guide to Heat Pumps today. I hope you find it helpful, and feel free to start a new topic dedicated to your journey when you're ready. 

@editor I have registered with Heat Geeks, and the installer they have asked to contact me is from RA Brown interestingly…. Aira are also coming over for an assessment, and Ryan from Installio is in contact, so it could all be kicking off. Looking forward to diving into the book too.

@editor I am now starting to look for firms serving West Oxon (Witney/Burford) area. Can you recommend any? Although I'm replacing an existing ASHP I want to start at the beginning.

Thanks,

Mike

Hi, I’m new to the group, I’m based in Gloucestershire (GL11) and would like to find reputable installers in my area to quote for a boiler to ASHP install. I am planning some upgrades myself, more insulation, underfloor heating and new triple glazed windows and a MVHR system, so would need an installer that I could work with to get the detail right.  I would appreciate any quality recommendations.

@nick-organ I’ll connect you tomorrow Nick, but if there’s anyone else out there with a suggestion for an installer in Gloucestershire, please post below.

@editor1 Thanks Mars, I look forward to your recommendations.

Two quotes in so far, Heat Geeks and Installio. I would be interested if anyone has experience of Installio as an installer. HG have designed a system that they say requires only two new radiators, even though several are 45 years old; Installio’s design is based on 10 radiator changes. Both companies have taken great care with their measurements and surveys; both make compelling cases for their designs and their technicians doing the surveys have communicated well. The prices are different as you can imagine, but not not wildly. Any help or comment would be welcome!

@silver-fox 

What flow temperature are they each designing for and what house loss are they estimating?  This will likely explain the difference.

@silver-fox I’d be interested to know if Heat Geek are coming in higher on price, and also what brand of heat pump Installio are quoting for. I assume Heat Geek are going down the Vaillant route?

@jamespa HG are guaranteeing 390% efficiency but have not given a specific top flow temperature, but emphasise that this will be variable; they have measured12Kw heat loss. Installio state that 45 degrees at -3C is the aim, with 10Kw heat loss measured, 415Kw efficiency for heating, SPF 3.4. Both recommend 12Kw heat pumps.