Moving Duct Work


  #1  
Old 02-26-04, 10:14 AM
wayfarer777
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Moving Duct Work

I currently have a cold air return on a half wall in my living room. I will be removing the half wall, and thus will have a hole for the cold air return in the floor, which runs into the basement. My house was built in 1979, so the "duct" in the basement is simply a piece of metal flashing attached across the joists in the basement, which leads to the furnace. I was going to simply patch the hole in the floor and cover it with the flooring I'm installing and open up the duct work, which is in the basement, to pull air from the basement, rather than from the living room. I don't see an issue with this, but then again I'm a novice to this stuff and wanted to ask the experts. I live in Littleton, Colorado, so if anyone knows about the local codes in my area, that would help. And any advice is appreciated.

My other option would be to cover the hole in the floor with a grate of some kind, but I'd rather not have something like that in my living room. There is another return in dining room. The square footage for this level is only 600sf. Is there a minimum number of Sq. Ft. per return?

Thanks,
Kevin
wayfarer007@netzero.net
 
  #2  
Old 02-26-04, 11:02 AM
Ed Imeduc's Avatar
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The way things are Id check on code there for sure. You dont say how many heat outlets do you have there in the 6oo sq ft? If you put it in the basement how would the air get to it from up there ????Try and see how hard does the blower pull air from there now when on???? ED
 
  #3  
Old 02-26-04, 01:07 PM
wayfarer777
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I have 4 heat outlets on that main floor.

I'm not sure what you mean by: "If you put it in the basement how would the air get to it from up there ????"

Does it matter where the cold air return brings in the air from? I mean as long as it's getting air from inside the house, does it effect furnace performance?

It would pull the same amount of air, it would just be pulling it from the basement versus from the living room.

Thanks,
Kevin
 
  #4  
Old 02-26-04, 01:25 PM
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You have it right as far as the furnace and air goes. BUT think this way A room big or small is still like a balloon. so when I go to blow hot air into it I can only blow so much in then I have to let some out to get back to the furnace so I can heat it again.

This is why I said play with it. Put a board over it to block it off. see how the other one will pull. Also when the blower is on and that hole blocked try an open the blower door on the furnace and see if thats harder with that cold air blocked off . This all will tell you a lot

4 outlets not bad but we do have to get some air back. You could open it in the basement like you said and cut some off the bottom of the basement door if you have one there. if the stairs are open you got it made

When you dont see the whole job its hard to say just howED
 
  #5  
Old 02-26-04, 06:23 PM
wayfarer777
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Thanks Ed. I really appreciate the response. I know it must be difficult sometimes, since you can't see the job. You guys that monitor this site, do a great job. That sentence about the balloon, though, clears up some thoughts in my head about it. I think I can go forward and will probably keep the vent and just put it coming out of the floor, instead out from the bottom of the half wall.

Anyway, thanks again.

Kevin
 
  #6  
Old 07-08-07, 12:18 PM
J
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same situation here

hello,
I just read your posting about the cold air return duct, and we're facing the exact same situation with removing a wall on our house. I know a bit about heating being an apprentice gasfitter, but I also don't know exactly how much return air you need-is there a formula per square foot of space or something. I do know for sure though that if you're going to take the air from the basement, try not to take it from the room the furnace is in (if it's enclosed.) This can affect how much combustion air your gas appliances have available to them and can affect how they draft up the chimney. Let me know if you've learned anything regarding how much return air is required.
Jared
 
  #7  
Old 07-09-07, 08:36 AM
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Wink

AS far as size of duct .You have to get a duct calculator to do it right.
But a good way to go. Like is that you need 80 sq " per ton for a very very good job and 60sq" per ton for a tight job. Most end up with 70sq" per ton and works ok. This would be for the return duct size at the blower and the plenum outlet duct.
 
  #8  
Old 08-07-07, 06:55 AM
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Moving a Return

I've run into a similar conundrum, creating a doorway in a 1st floor wall where there is duct work for the 2nd floor returns running up the the center bearing wall. I've got returns running for 3 bedrooms plus the hallway (4 total in evenly-spread stud bays), then they exit the wall about a foot below the ceiling on the 2nd floor in different rooms. Can I remove one of these returns altogether, or perhaps even remove the duct going down and instead run flex in the attic to connect a couple of them together & share the "home run"?
 
  #9  
Old 08-07-07, 07:49 AM
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Jump duct

as a follow up to my question below, I've done more digging online and see that jump ducts may be a solution to my problem... could I remove the return duct from a bedroom and instead run flex pipe up into the attic & down into a ceiling vent in the hallway? Thanks in advance for your help, I've been surfing around this site and it is amazing the amount of good info that is available. thank you!
 
 

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