Advice on how to optimise Heat Pump and MVHR system

jdaltonglin

Hi All,

I am 2 months living in our new build house which has a Bosch 7001i 9kW Heat Pump and a Vent Axia Kenetic High Flow MVHR. There are stats in most rooms, it is a two story and 221m2.

Anyway being in the house for a few months and finding it hard to get my head around the system. We like a house relatively cool and the sweet spot for us seems to be about 19.5degrees. We find 21 degrees too high for example.

We had the main controller on the Heat Pump set to 21deg to start with and have over the past few months reduced this to 18.5deg. And in the rooms we have reduced all these to 18.5deg as well.

The issue we are having is that the the changes made to the main controller and the rooms don't seem to have made any difference. The upstairs sits at roughly 21.5deg and downstairs at roughly 21deg. In addition with the bad weather recently - we got lots of snow, the system seems to be working in overdrive and has upstairs up to 22.5deg and downstairs around 22deg.

So basically I am wondering if anyone has any experience of this in their house with a similar set-up or any advice with what may work to reduce the house temperature down a bit.

Now I have done a bit of research and from what I can tell the Heat pump works solely off the outside temperature. It is not connected up at all the the room stats. The rooms stats are only hooked up to the MVHR system. It looks like the Heat Pump looks at the outside temperature and decides based on curves the amount of heat the house needs. I know it can be hooked up to a single internal reference point but not sure how that works etc.

There are lots of things in the Heat pump settings I could play with - different setting for night and day using something called "setback"? I could change the curve used to compensate for outside temperature, or another thing I saw was something to do with the house itself, whether it is Heavy, Medium or Light - in some way relating to the wall thickness I believe. Its currently set to Medium.. so I could set it to heavy?

Also no idea how the MVHR interact with all this, if all rooms are higher than the temperature you set for each stat.. does it do anything?

Doesn't seem to be any resources for this online in Irish/British weather set-ups. So any info I can get of anyone here would be very much appreciated.

DC999

Try posting here instead maybe, it's specific to heat pumps. Lots of good info in the older posts too:

Heat Pumps - post here. - Page 74 — boards.ie - Now Ye're Talkin'

jdaltonglin

Thanks @DC999 I have done that. I did see that thread but that looked mostly to be dealing with the construction part and what to get etc. But then again with 74 pages I'm sure there is some stuff in there :)

Padre_Pio

https://www.boards.ie/discussion/2058387646/advice-on-how-to-optimise-heat-pump-and-mvhr-system

Not sure abotu your specific heat pump, but make sure it's set react to the thermostat.

there are other heating profiles that use the outside thermometer and a temperature curve.

jdaltonglin

Thanks @Padre_Pio I am going to talk to the Plumber about that but I as far as I can see a new specific thermostat will need to be put in to a referrence room and wire from that to the heat pump. Bit late in the day to have to up that in, with the house all plastered etc. but may have to go there.

Calahonda52

OP, how did you arrive at this conclusion

"The rooms stats are only hooked up to the MVHR system."

If so its a new one on me

How many room stay do you have?

How do you control the DHW temp?