Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)


Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.

Buy individually or both books together. Delivery is free!

powered by Surfing Waves

Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.

    • CommentAuthorSilky
    • CommentTimeNov 6th 2020 edited
    Not sure if anyone can advise me, I'm putting up a facade before the installation of a heatpump in the future( too much on to deal with the heating at the moment.)

    The overall wall+facade build-up gets pretty massive ( 1/2 metre deep or more ) so I don't fancy trying to put pipes through there later on. I'm imaging an idea now, that I put something like 50 mm PVC pipes in the facade and wall as I build up, then just leave these capped off. Later on they could take the pipework for the heatpump and be closed up with something. If the heat-pump is changed or there is a problem with the pipes the holes could be cleaned out and re-used. Did anyone do something like this, think it is a good or bad idea etc..? Have never installed a heat pump...yet so need to ask for the 'unknowns'
    • CommentAuthortony
    • CommentTimeNov 6th 2020
    Definitely a good idea, fill with insulation or foam - don't use metal. use bigger ducts than you think you need or more.

    I would do an underground duct to behind the garage or shed
    • CommentAuthorJeff B
    • CommentTimeNov 6th 2020
    As Tony says I wouldn't think a 50mm diameter pipe would be big enough as the ASHP pipes will need plenty of insulation. Maybe 110mm uPVC underground pipe?
    Good plan, but make them bigger, 100 mm or have several. The heat pump will have two pipes each 22 or 28mm dia with 19mm insulation on them, a chunky power supply cable and a smaller control cable.

    When ours was fitted it took one guy the best part of a day to drill all of the holes through the granite wall. Later, he removed some plaster a few feet away, to reveal a section of soft brick wall, I thought he was about to cry :-(

    Actually you have a good idea to have spare pipes/ducts in several places. I currently need to drill holes for wires for outdoor lights and a condensate drain pipe, and there will need to be holes for fibre broadband and EV charger cable at some point soonish, some spare ducts would have been really helpful.
    • CommentAuthorbhommels
    • CommentTimeNov 6th 2020 edited
    This is a great idea! And worth stealing too, as I am about to install EWI soon-ish and will therefore end up with 400+ mm thick walls. So 2x 50mm or bigger PVC pipe & a small bore one for electrics?
    • CommentTimeNov 6th 2020
    The pipe diameter will depend on whether it's a monobloc or split system. It sounds like people are describing monobloc requirements. The pipes are slightly smaller on a split system, I believe, but you would need to check details with the manufacturer or oversize. I'd note that multiple holes to fit the individual pipes and another for the electrical cables will likely have smaller cross-section than a large one to take them all, which might be an improvement for several reasons.

    I have a few conduits laid through warmcel, which were 'interesting' to drill. The stuff gets all tangled around the drill; still better than trying to go through straw though :confused:
    Unless I missed it further up - What is the wall construction we are talking about? Brick, timber frame granite or what have you and what is the facade construction?
    • CommentAuthorSilky
    • CommentTimeNov 8th 2020 edited
    Thanks for the reassurance and other tips.

    Peter the wall buildup is something like 360mm Poroton or 240mm brick + 180mm void with Cellulose + 40mm woodfibre sarking board. Also renders and plasters over the existing brickwork. One of my concerns is that when drilling later it would make a mess of the insulation and it would be difficult to control debris falling into the void. In the ground perimeter area up to a height of approx. 300mmI have 140mm EPS. Due to a rare risk of flash flooding I'm generally trying to avoid putting anything too near the ground but could be an option for these pipes. I would prefer to keep electrics higher up.
Add your comments

    Username Password
  • Format comments as
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   

© Green Building Press