Nilan MVHR Compact P - Smart home questions

[JonDoe]

Hi, I've bought an home with a Nilan MVHR Compact P AIR it last year. Since then I managed to understand a lot about how the system works (and the errors that were made by the previous owners). I'm looking for opinions and suggestion, I need a sounding board.

First year of use:

Nilan MVHR Compact P AIR - with CTS 602 control unit.

External heating is provided by solar gains and electric wall mounted heaters.

Property is a 4 bed + study detached (about 130sqm)

Energy consumed 3600 kWh

Energy exported 1600 kWh (small 2kWh south facing PV installation)

Standard variable energy tariff (no other tariffs where avaible at the time)

I've just had a SMETS 2 Smart meter installed  - Landis & Gyr E470 type 5533
 

From the EPC

Feature    Description    Rating
Walls    Average thermal transmittance 0.12 W/m²K
Roof    Average thermal transmittance 0.11 W/m²K
Floor    Average thermal transmittance 0.12 W/m²K
Windows    Triple glazing
Air tightness    Air permeability 1.1 m³/h.m² (as tested) 
The primary energy use for this property per year is 27 kilowatt hours per square metre (kWh/m2)

 

At the moment I've set the system to run 24/7 at the lowest speed (unless there is a need to cool/heat the house or provide hot water, then the programming kicks in).

The tank is 150lt I believe. The water temp is set to 60C, with 25C being the point at which the electric immersion heater kicks in. in the 25C to 60C range hot water is created by the heat pump. The highest threshold point is 80C. Water is only heated above 60C when the cooling functionality is required (I believe).

 

I'd like to switch to a Octopus Agile tariff (I don't own an electric car yet) so I need to be able to tell the system to not replenish the hot water during certain times of the day (mostly between 4-7PM). 

My plan is to use cheap energy to heat the water to an High temperature and then use the MVHR to distribute the heat from the tank through the house, and to boost the house temperature with the wall mounted heaters when necessary. Unfortunately the details of the programming for the heating functions aren't available from the CTS 602, I can't control the thresholds etc.

 

Any help and any suggestion is greatly appreciated. This is our first home the learning curve gas been a bit steep but I've enjoyed the challenge since I work in IT QA.

 

Cheers

Edited September 1, 2023 by JonDoe

[JonDoe]

After reading the instruction manual again, I don't think the above can be achieved.

The problem we had last winter was that the Compact P on it's own can't heat the house by itself.
According to the manual "In the winter, the built-in heat pump can heat the supply air up to 34 ° C, and thus contribute to heating the home. When the supply air is heated, at the same time a little heat is deposited in the hot water tank and ensures a constant high hot water temperature."

When setting the temperature in the termostat to 21C, the program would allow the temperature to go down to 16C before kicking in the electric heaters. So the only way to force the heaters on was to set the temperature to 26C or something silly like that. I'll try to ring the assistance to see if that behaviour can be corrected but last time I spoke with them they said it's "normal" and I did the right thing by forcing them on manually.

Edit: It seems that the two functionalities I'm interested in are the smart grid functionality available with the CTS 700 https://www.manualslib.com/manual/2066873/Nilan-Cts700-Touch.html?page=35 and the external heat supply (which I can't find in the control unit) https://www.en.nilan.dk/Files/Files/Engelsk/Downloads/3. Installation instructions/2021-09 M24 Compact P AIR9 GB.pdf

Edited September 1, 2023 by JonDoe

[JonDoe]

Given that Nilan UK couldn't be bothered to give me a quote to replace the old interface with a touch one or reply to any of the question above, in the end I decided to integrate the Nilan Compact P with Home assistant and be free to interact with it however I want for a total cost of about £60. Next step will be running the MVHR to make hot water when we have loads of PV energy or the best octopus agile tariff for the day.

[pjc78]

Hey @JonDoe I also have a Nilan Compact P. Is there any chance of getting the details of your Home Assistant setup and configuration?  Thanks 

[Kevin Dawson]

@JonDoe am just pressing the button on a Compact P XL for our newbuild and would also like to know how you integrated it with HA (the Nilan guys closed down that discussion when I asked if it was available/planned).

 

Thanks in advance.