Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Thermostat mount air leak

Turbo DaveTurbo Dave Member Posts: 57
Hello all. I am replacing several dozen thermostats in an old school. The wind coming through the metal electric boxes they are mounted upon must be stopped. What is the most effective solution to this problem? Thank you.

Comments

  • PC7060PC7060 Member Posts: 75
    The best thing I’ve found is dense packing fiberglass insulation into the box and cavity. It’s an approved fire block and is a very good job stopping air movement.  Fire retardant spray foam is also an option but it’s a real pain later if you have to get back into the box
    Turbo Dave
  • ChrisJChrisJ Member Posts: 11,343
    At my own house I've used Aeroflex pipe insulation foam.
    Much nicer to handle than fiberglass and blocks air better. Some of the 3/4" thick stuff works well. McMaster has that as well as other types of similar foam.

    However, it's certainly not a fireblock.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    Turbo Davemattmia2
  • chiefchief Member Posts: 17
    For air flow blocking in electrical conduits per code we use duct seal. Sold in 1# blocks. Available at some big box stores and at electrical wholesale houses.
    mattmia2Turbo Dave
  • mattmia2mattmia2 Member Posts: 1,991
    If the box is removable wrapping the outside with a sheet of polyethylene and sealing around the tubing or cable is also an option. Lining the box with sheets of sealant like what is used to flash window also would seal it up.
  • PC7060PC7060 Member Posts: 75
    edited August 1
    “For air flow blocking in electrical conduits per code we use duct seal.”
    @chief makes good point.  Good material and is only correct solution if line voltage is present in box.  
    Not code required assuming low voltage only. 
    mattmia2
  • mattmia2mattmia2 Member Posts: 1,991
    PC7060 said:

    “For air flow blocking in electrical conduits per code we use duct seal.”
    @chief makes good point.  Good material and is only correct solution if line voltage is present in box.  

    Not code required assuming low voltage only. 
    I was thinking low energy or pneumatic, but you have far fewer options if it is line voltage.

Leave a Comment

BoldItalicStrikethroughOrdered listUnordered list
Emoji
Image
Align leftAlign centerAlign rightToggle HTML viewToggle full pageToggle lights
Drop image/file

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!