Service penetration for 3 phase in passivhaus

[Barny]

Hi

 

we are aiming for passivhaus certification and have 3 phase electric. Has anyone done this? What size ducting did I you use for the electric penetration through your foundations?

 

we have 150mm ducting for the cable to TBS but that seems large Togo through foundation. I know we need the insulation and airtight tape around the cable but still seems like 150mm is large.

 

many thanks

[IanR]

Mine is in 100mm duct, through an insulated raft foundation, without any airtight tape.

 

The largest duct we have through the floor is the pre-insulated twin pipe duct for the ASHP, which is 150mm.

[Barny]

Thanks Ian. Is that an insulated 100mm duct? Thanks

 

[IanR]

22 minutes ago, Barny said:

Thanks Ian. Is that an insulated 100mm duct? Thanks

 

 

Not for power, water, comms etc. just the ASHP supply and return is insulated.

 

I used a rigid 100mm duct for power and did wrap the outside in a 20mm thick foam, where it was cast into the concrete floor. I did this with all ducts to reduce their chance of fracturing if they were ever knocked.

 

Grey rigid in the background close to the centre was for power and comms, blue flexi is water, black (long) flexi is for ASHP comms and the shorter larger black one that's taped up is the ASHP feed and return. Brown rigids are obviously waste.

 

[Barny]

Thanks - very neat!