Tagged Questions

1
vote
2answers
89 views

Is it safe to install a heating duct register in the ceiling directly above a home entertainment center?

We're in the process of getting bids for central heating and one of the conundrums is where to position the registers. Due to the layout of our living room (and style preferences of my significant ...
8
votes
2answers
528 views

What does a Summer/Winter switch on furnace air ducts do?

On some of our furnace ducts, there is a switch/valve for Summer/Winter or S/W. What does changing this switch/lever accomplish? Can bad things happen if I forget to switch it? Bonus question: ...
4
votes
2answers
266 views

Do joints in adjustable duct elbows need to be taped?

Do the joints in adjustable duct elbows need to be taped as well once they're adjusted or are they considered air-tight?
3
votes
1answer
193 views

How do I support vertical runs of round ducting?

Supporting ducts horizontally seems pretty straight forward--just a loop of strapping underneath to support it. What about when the duct runs vertically? Do you use the same kind of strapping but ...
2
votes
1answer
166 views

What is involved in sizing and designing ducts and ductwork?

I have a one-story house, and it looks like it would be easy to run new ducts myself in the attic. What should I know before trying to design a duct system myself? I have seen ductwork that's metal ...
4
votes
1answer
1k views

How should one size ductwork for a new air return duct?

I recently had a contractor build a wall which split one room into two. The new room is an office with two computers, and four monitors. It gets very, very hot, until the air conditioning turns on, ...
2
votes
1answer
716 views

Does an air return duct do anything when the air conditioning or furnace is not running?

I recently had a contractor create a new wall which cut me off from the rest of the house. There is one AC/Heating vent in the room and when the door is closed it gets very, very hot. As soon as the ...
3
votes
2answers
891 views

Can I increase air volume by adding more fans?

I have a straight 25 foot rectangular duct that is 0.9 sqft in cross-sectional area (11" by 12"). There are openings on either end, and nowhere in the middle. I wish to move about 1000 CFM through the ...
2
votes
1answer
279 views

Replace 7“ metal duct with 6” flexible or 8" flexible?

I am replacing the flexible ductwork in my attic, which is a mix of ancient 6" and 7" metal ducting. I'm having a hard time finding 7" flexible ductwork for sale locally, but no problem with 6" and ...
3
votes
2answers
1k views

Is a lip necessary on an HVAC ceiling register boot for use with flexible ducting?

I've installed some new ceiling register boots to use with flexible ducting and realized after install that they have a smooth connection with no lip. I'm assuming they are made for metal ducting, as ...
3
votes
1answer
383 views

How do I replace an A/C diffuser attached to flex duct?

Our house has central air, with the air distributed via flex ducts around the house. On the second floor, the diffusers have baffles behind them that can be closed when the system is not in use, but ...
3
votes
1answer
83 views

It is reasonable to expect a contractor to replace the last foot of HVAC duct work, the connection between the insulated duct and the register?

The contract was to replace an antiquated HVAC and duct work. Since the registers are a standard size, would this connection also be a standard pre-fabricated part? What is that last connection ...
2
votes
0answers
125 views

Is mold growing in my ductwork? [closed]

I am currently in a battle with my landlord over what I believe to be mold growing on the fiberglass liner of the ductwork in my apartment. He is having a specialist come to test it tomorrow, and I ...
1
vote
1answer
343 views

Installing a duct fan

For a room in the basement we connected a ceiling register to an existing duct. It is not very strong, but I found this product that might make it a little more powerful: Does anybody know how ...
1
vote
1answer
132 views

Fan between rooms?

I presently work at home, which means that I spend a lot of time in my office (ya think?). Unfortunately, this room is not a good one for air conditioning (or heating) in the house. I can often get 8 ...
3
votes
1answer
190 views

Improve AC flow to secondary ducts

I have an AC which has 3 ducts coming out of it. Only one duct gets flow - I'm guessing the AC fan blows right into it. What can I do to improve the flow?
2
votes
2answers
452 views

How do I repair loose ductwork?

The ductwork in our 30 year old house has started coming loose where it comes up through the floor. It's nailed to the subfloor, but in several places, the nails have come loose, leaving gaps of an ...
3
votes
2answers
2k views

How do I install a jump duct?

Our master bedroom is considerably warmer than the living/dining/kitchen area of our house, and we've been setting the thermostat quite lower than we'd like in order for the bedroom to get cool enough ...
12
votes
6answers
495 views

Is it worthwhile to have ductwork cleaned?

Was rearranging some ductwork in my basement, and noticed that the stuff I took down was pretty filthy inside (especially the return air ducts). Is it worthwhile to have ductwork cleaned out? What ...