MVHR and cooling

[Nic]

Hi 

 

after some thoughts and opinions. 
 

building a small two en-suite two story house making it as passive as we can thermal raft airtight etc UFH 

likely to fit a Zehnder ComfoAir Q350 ( in first floor roof space… 

 

we are in Devon so the heating side of our property ( with the insulation, UFH, triple  glazing etc) is not likely to be much of a problem 🤞🏼

my main thoughts are on cooling…. Space is limited, anyone know what the most effective way to go on this from the start?  as I’d like to avoid having to retrofit something. I’m not likely to fit full blown air con unfortunately 
 

[JohnMo]

UFH system and fan coils in bedrooms, run everything direct from the heat pump at a single flow temp - around 14 to 15 degs via a simple WC curve.

[WisteriaMews]

We're planning a certified passive house and are looking to install a Zhender ComfoAir Q450 with the Zhender Comfoclime bolt on that does heating and cooling. Assuming we hit the passive house standard, that should be sufficient for us.

 

I see you mention above UFH (and also have seen your other post about ASHP), if you get a heat pump that can reverse you could do both via the UFH; heat the slab in winter and cool it in summer.

[MikeSharp01]

  On 24/08/2024 at 21:22, WisteriaMews said:

We're planning a certified passive house and are looking to install a Zhender ComfoAir Q450 with the Zhender Comfoclime bolt on that does heating and cooling. Assuming we hit the passive house standard, that should be sufficient for us.

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Sounds like a plan the PHPP software will tell you if it's a goer!

[WisteriaMews]

  On 25/08/2024 at 05:48, MikeSharp01 said:

Sounds like a plan the PHPP software will tell you if it's a goer!

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PHPP tells us it's sufficient. Still feels like a bit of a leap of faith installing such a low power system.

[MikeSharp01]

  On 25/08/2024 at 06:01, WisteriaMews said:

PHPP tells us it's sufficient. Still feels like a bit of a leap of faith installing such a low power system.

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Then it should be OK but check the technical guff on the unit to ensure it can deliver under your circumstances - I dimly recall you need to have a given output temperature for the unit to get the tick in the box and that's a variable.

[Nic]

  On 24/08/2024 at 21:21, JohnMo said:

UFH system and fan coils in bedrooms, run everything direct from the heat pump at a single flow temp - around 14 to 15 degs via a simple WC curve.

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WC curve ? 

[JohnMo]

  On 25/08/2024 at 06:41, Nic said:

WC curve ? 

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Weather compensation curve

[Dave Jones]

forget MVHR for cooling, we have the Q350 with the expensive heat/cool battery and its totally useless for cooling. 

 

The fancoils on the other hand amazing. Just insulate all the pipework to them and run a condensate drain to them.

[Dave Jones]

  On 24/08/2024 at 21:21, JohnMo said:

UFH system and fan coils in bedrooms, run everything direct from the heat pump at a single flow temp - around 14 to 15 degs via a simple WC curve.

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14 is a bit cold ?

[JohnMo]

  On 25/08/2024 at 09:01, Dave Jones said:

 

14 is a bit cold ?

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Work fine for us, but we do cycle on the heat pump (it's too big) so average is possibly closer to 16-18, depending on solar gain.