Thanks for tuning in to our Question of the Week series.
This week’s question comes from a builder who knows that one of the keys to executing an airtight building cost-effectively involves thinking carefully about penetrations.
“We are using a combination of Intello Plus on the interior with Prosoco R-Guard system on the exterior of a current house. It’s not officially a passive house but we are working for that level of air sealing. I bought a PHPP package from you that we used in design.
Our biggest challenge in our last house was the mass of penetrations for the electrical service panel. In that house we used a section of black pipe air sealed into the exterior barrier and then taped and foamed the wires inside the pipe. This worked well but I’m concerned of the durability.
I would like to find a more elegant solution to this and am considering ProClima penetration products but can’t figure out the best/right way to handle this. It seems like a location every house has to deal with but I’ve been surprised to have never seen it talked about. What am I missing?”
Thanks for the question. Good to hear you are using the PHPP and that you are focusing on airsealing.
The electrical panel can be tricky, especially if it is located in a difficult spot. We can suggest a few solutions:
2. Have the meter outside, and the main panel inside – You will have one wire in, and a wire out for the heat pump and any exterior outlets – though those could go at at a separate location – then your outside lights etc.
3. It is our recommendation to split wires as much as possible. You can use KAFLEX or KAFLEX Multi for small wires – and ROFLEX 20 for the big conduit (however it is sometimes not round so you might be better off taping it bit by bit – see here (at minute 1) for some nice tricks to do this easily).
Habitat for Humanity in Washington DC has some interesting solutions for penetration sealing that they introduced in our 475 On-Site video this winter. They involve consolidating all wires into one PVC pipe, to combine and seal penetrations together. Begin watching the video below at 6:45 to see the explanation:
Sealing holes from densepacking below a subfloor? Use a tapered plug with some Tescon Vana tape.
Sealing a duct penetration? Use Roflex gaskets for ducts from 2″ to 12″.