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  1. Vent in Wall, Slit Below

    I am remodeling a 1972 built house. Second floor bedrooms have a vent on top of wall and a slit in wall at floor level. I don’t know what it’s for? The baseboard would cover up the slit. Only the master bedroom vent goes below the decking. Can some please explain theory? See picture.
  2. Fix poorly installed AC

    Hi Everyone, I've been reading posts for quite sometime and decided to join and ask a question. I bought a house 2 years back in Eastern PA so it gets hot & humid here. The guy who owned the house before me has everything in this house rigged. It's a split level house with 4 levels -...
  3. Question moving vents

    Changing some things in my HVAC ductwork and have a few questions(this is all in the basement btw: 1. What's the best way to seal off a supply just use thermopan? 2. I'm also moving a return. What is the best way to cut out a new vent hole in the return trunk?
  4. Duct Board Bad?

    So I got some Knauf Duct Board at a very good price. However, once I got it home it seems very...fibrous. I run my hand calmly over the fiberglass portion and it feels like i'm scraping off very small particles. Is this normal? It has the intent of being used as a return plenum so air flow...
  5. Flex Duct

    Can flex duct be used in place of a normal return plenum? I've read it can so long as it is not the only return in the house but not sure how good the source was. 8" is probably the biggest I can use but the plenum takes up 2 joist cavities, so run 2 flex ducts? Thank you.
  6. Surprise when I pulled the returns off.

    Building & Construction
    So I removed the Panning for the returns and I found this going on. Is that hole there so the wall can breathe? Can I close it off? It connects to the return for the room upstairs and that is an outside wall.
  7. Remodeling and need return vent advice.

    Hi, I'm Brittany and this is my first post. I am planning a remodel for my two bedroom 800 sq ft house. I plan to section off the two bedrooms and make a small efficiency apartment so that I can have a roommate. I have a gas furnace with one return which is located in the area sectioned for...
  8. running ducts in the basement

    Hello. I'm finishing my basement and I am getting ready to do the heating. Is there an easy way to run ducts down the walls? Also the permit says that I will need to have a high and low return vent. And configuration of air in the mechanical room. It will be about 1000sq ft finished and 250 sq...
  9. Air intake/return on an oil furnace

    Hello, I have a question about the air intake on an oil furnace. There is a big vent on the lower area of the furnace and the inspector said this was the only intake. He said we should have intake ducts coming in from the second and first floor, or only first floor at a minimum...but not...
  10. Cold air return in the basement

    Hello, I need to take a cold air return in the basement to the floor level. One of the options I was considering is to cut the top plate as shown on the image (stud on the left is missing) and cover the space between the joists with sheet metal for the upper part. For the vertical part of the...
  11. Sealing air return duct

    Hi guys, new member here. I've done my share of projects around the house, but never done any HVAC work before, so please bear with me. I'm trying to seal the return air duct on my furnace (non-condensing, down draft). The return duct is made of galvanized sheet metal (rectangular - 24" x 10" x...