MVHR & ASHP best options

[G and J]

1 hour ago, Nick Laslett said:

The Fancoil approach had not matured

And ever it is thus.

 

It seems the minute we buy anything they bring out a better one which is kinda annoying but that’s progress.  Except sometimes ‘better’ is just different and it does the same job.  C’est La vie. 

[JohnMo]

6 hours ago, G and J said:

And ever it is thus.

 

It seems the minute we buy anything they bring out a better one which is kinda annoying but that’s progress.  Except sometimes ‘better’ is just different and it does the same job.  C’est La vie. 

Not sure that is really true for fan coils, they have been about very little changed for decades. But the context has moved, were really only ever used in commercial buildings, not homes. The thing that has changed is heat pumps are being installed, people realise they can cool as well as heat. The fan coil in a domestic setting is the thing starting to mature. But a long a long way go yet.

[joe90]

I have installed fan coils in kitchens where wall space was not there fir radiators, fitted in the kickboards.

[G and J]

Just now, JohnMo said:

But a long a long way go yet.

That’s certainly my impression.  If you look at the engineering involved they should be less than £100 a pop but the volume isn’t there yet.  

[JohnMo]

54 minutes ago, G and J said:

That’s certainly my impression.  If you look at the engineering involved they should be less than £100 a pop but the volume isn’t there yet.  

Would agree. But there are only a few manufacturers and a lot of re-badging going on and a commercial premium, buy lots big discounts on RRP, but buy a couple get charged full wack.

[Nick Laslett]

20 hours ago, JohnMo said:

The thing that has changed is heat pumps are being installed, people realise they can cool as well as heat.

This was the key change for me. My memory of the research I was doing in back 2019, was that the RHI government grant at that time, did not allow an ASHP to be installed with cooling enabled. There was some confusion on the BuildHub site from other members what the MCS would allow and many heat pumps, just did not actually have cooling capability at all. I only decided to go with a Panasonic AShP, because fellow member @jack had one and he had enabled the cooling mode. I can’t remember if it was @Josh or another member that imported their Panasonic fan coils from Italy.

[Crispy75]

I hope @James Allen doesn't mind me hijacking his thread to ask similar-ish questions.

 

My project is a whole-story extension and external insulation to the whole house. Aiming for EnerPHit (although not bothered about certifying), and have got the numbers in PHPP down to 1.9kW (15W/m²) heating load and 1kW (8.3W/m²) cooling load. It doesn't take much of a boost in airflow rates to get PHPP to say Yes to both heating and cooling via supply air (190m­³/hr =52l/s). First I went looking for all-in-one solutions and got quoted an absolute fortune for the PKOM4 (£25k! Excluding install and commissioning!!)

 

Now I think the ComfoPost as reccomended by @Nick Laslett alongside a more off-the-peg ASHP. The Zehnder literature seems to think so anyway. What air flow do you run yours at Nick?

 

 

[Nick Laslett]

@Crispy75, my MVHR is not commissioned yet. I would be somewhat hesitate at this stage to recommend the ComfoPost without these caveats. There are other members like @Dan F with more experience, with good comments in other threads. I won’t be running the water in my ASHP in cooling mode any lower than 13°C. My aspiration is to knock 1° to 1.5°c off the house temp with the ComfoPost. Looking at the design spec for my install the supply air (240m­³/hr =67l/s). Hope that helps. 

 

 

Edited September 6 by Nick Laslett

[JohnMo]

11 hours ago, Crispy75 said:

doesn't take much of a boost in airflow rates

I would be wary of doing that, just because of the amount air drying that will go on - you could get an unhealthy humidity level mid winter. Even just below normal levels of ventilation last year we were getting to 30% humidity. Bumping up ventilation rates and heating the air - not sure I would.

 

Heat pump and fan coils kor UFH and fan coils in bedrooms) or A2A and separate MVHR.

 

[Dave Jones]

On 06/09/2024 at 22:49, Nick Laslett said:

@Crispy75, my MVHR is not commissioned yet. I would be somewhat hesitate at this stage to recommend the ComfoPost without these caveats. There are other members like @Dan F with more experience, with good comments in other threads. I won’t be running the water in my ASHP in cooling mode any lower than 13°C. My aspiration is to knock 1° to 1.5°c off the house temp with the ComfoPost. Looking at the design spec for my install the supply air (240m­³/hr =67l/s). Hope that helps. 

 

 

 

i have the comfopost, its crap. honestly dont bother. for the price of it you can get a lot of fancoils which do actually work.