MVHR - wiring for boost function

[osmononame]

Hi all,

 

My build is well on the way and we are now at the wiring stage. The plan is for me and an old time/retired sparky to do the bulk of the labour / running of cables and then pay someone to come in and give it a once over / commission / give certificate etc when required.

 

I want a boost switch in the kitchen on its own switch and then ensuites to boost when the light is switched - i don't want a separate switch here. The MVHR unit I have is a Zehnder Q600 so the question is what wire do i run from the bathroom light switch to the Q600. I am thinking a twin and earth cable from the switch to the Q600 but the Zehnder requires a low voltage input so how is it step downed?

 

I know i should just pay someone to do this for me but funds are tight so trying to get as far as I can before I need to get someone in.

 

thanks.

[Nickfromwales]

17 minutes ago, osmononame said:

The plan is for me and an old time/retired sparky to do the bulk of the labour / running of cables and then pay someone to come in and give it a once over / commission / give certificate etc when required.

Check that you have someone that is willing to put their name, badge and insurance to a job they did not install. Not all sparks have the necessary certification to sign off works done by other. It is quite important to get that understood now, so that individual can come and observe all cable ways / fixing methods / containment / regs & legislations have been observed BEFORE you cover ANYTHING up  

 

I fit simple reactive switches on CAT6 cable for MVHR boost, but you need to know the MVHR unit supports an external signal prompt to boost rather than that having to be done manually at the ctrlr. Other cable types may also be required for different manufacturers / machines.

[osmononame]

3 minutes ago, Nickfromwales said:

Check that you have someone that is willing to put their name, badge and insurance to a job they did not install. Not all sparks have the necessary certification to sign off works done by other. It is quite important to get that understood now, so that individual can come and observe all cable ways / fixing methods / containment / regs & legislations have been observed BEFORE you cover ANYTHING up  

 

I fit simple reactive switches on CAT6 cable for MVHR boost, but you need to know the MVHR unit supports an external signal prompt to boost rather than that having to be done manually at the ctrlr. Other cable types may also be required for different manufacturers / machines.

 

Ok - thanks - so you don't have them running from the light switch but a separate switch instead?

 

And yes noted on the certification - I know to have it all checked out prior to sheeting and I am taking pictures of all my work along the way - my current house was done very much int he same fashion so i am not too worried on that front (although this build has a lot more to go wrong than before).

[Conor]

I'm looking at the zehnder units as well. They have a range of control options. e.g they have wireless controllers and integration with smart home sysyems. You'll need a control panel somewhere for the unit. I'm having mine in the kitchen so I can boost it that way. Will be relying on humidity settings for bathroom boosting.

 

This is a good list of the control options.

 

https://www.zehnder.co.uk/download/29632/118736/en_uk-72928.pdf

 

[osmononame]

7 minutes ago, Conor said:

I'm looking at the zehnder units as well. They have a range of control options. e.g they have wireless controllers and integration with smart home sysyems. You'll need a control panel somewhere for the unit. I'm having mine in the kitchen so I can boost it that way. Will be relying on humidity settings for bathroom boosting.

 

This is a good list of the control options.

 

https://www.zehnder.co.uk/download/29632/118736/en_uk-72928.pdf

 

 

Thanks - yes I know it has wireless options but tbh I have had a tonne of issues with some RF equipment here so was trying to wire where possible.

 

I think I would need to get an 'isolator relay' if I wanted to integrate with the light switch but I suspect that will be over complicating it for us. I have decided to go with cat6 runs (actually alarm cable runs which is what BPC told me i should be running) to each extract zone. I am hoping like you that the auto humidity function on the unit works well and will mean the switches are not required but better to have the wiring in place rather than attempt to retrofit or indeed run the gauntlet with RF.

 

Is it the ComfoSense C67 control box you are going for in the kitchen?

 

[Nickfromwales]

53 minutes ago, osmononame said:

Ok - thanks - so you don't have them running from the light switch but a separate switch instead

Yes. You can’t have SELV ( safety extra low voltage ) or signal wires in the same back box as the 230v stuff  ?