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Adding return air vents in bedrooms to reduce return air noise and increase total return air capacity

I did my homework here the best I could and I hope someone can help by checking my work. In an attempt to make things as clear as possible, I made the following diagram. This is my existing system ...
deefofum's user avatar
2 votes
0 answers
105 views

cold air return using resilient channel

I'm using resilient channel on a metal stud wall for sound reduction. The cold air return is in a wall that is not panned. The plan was drywall would enclose the area making it tight with airflow ...
Steven Jennings's user avatar
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110 views

Is there a "bending rigidity index" of some sort for semi-rigid aluminum ducts?

Some semi-rigid aluminum ducts bend easily and others do not. I want to purchase semi-rigid aluminum ducts online of a specific bending rigidity/stiffness that minimizes sagging but can be easily ...
Stephen W's user avatar
2 votes
0 answers
279 views

Would a radiant barrier help stop this heat transfer?

Using my nifty thermal camera, I discovered that my furnace closet's combustion air duct (visible in this question) is getting really hot when the attic heats up, and then (being sheet metal) it ...
iLikeDirt's user avatar
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How to add duct to return

Currently renovating 1920 house. Took down this wall and noticed this was or is the supply return for upstairs. What bothers me is there’s no duct connecting to the vent. I do feel air being sucked ...
Bryan's user avatar
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How can I reduce range hood duct size for best performance?

I currently have a range that was hacked in terribly by a previous contractor with flex pipe. I want to replace it with rigid duct to make it quieter and increase performance too hopefully. The range ...
cyboman's user avatar
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40 views

Air exchanger "fresh air to house" wye - should I leave it open or closed?

Background Just bought a house with a passive air exchanger: no internal fans, just motorized dampers moving air with the furnace fan. We have a thermopump, electric furnace and whole house bypass ...
msanford's user avatar
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1 answer
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OTR Microwave vent through wall, but on bottom?

I was replacing my over-the-range microwave and discovered the location of the existing vent. The vent is straight out the exterior wall, but down towards the bottom mounting bracket… I can’t seem to ...
Andrew Boisvert's user avatar
1 vote
2 answers
242 views

A/C vent not connected to duct?

So I am in the process of doing a light reno to a bathroom in my 1954 ranch style home and I took off the a/c vent to wash it and/or buy a new one. To my surprise (okay not really surprise— there was ...
Olivia's user avatar
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Furnace Return in basement

I have a duplex and one furnace crapped out likely because it had the return in the basement. It’s upstate NY, so it gets cold. If I want it done 100% right. I need ducts run all the way to the top ...
The Landlord's user avatar
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192 views

Should my air conditioner be running its air directly through internal spaces?

Should a newly installed “ducted” split system be running its intake air directly through internal spaces, or should I demand that the system be sealed so that it only draws air from living spaces? I’...
Alex Peters's user avatar
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2 answers
133 views

Can I remove this blocking in stud bays for a cold air return duct?

I've been troubleshooting a second floor cold air return that doesn't actually go anywhere. 1928 house, where 2nd floor was finished many years ago by other owners. I'm replacing the floor so decided ...
Jason Capriotti's user avatar
1 vote
0 answers
32 views

Duct filter damper

I have a couple active powered air filters hooked up on my ductwork. They are rated for 625 CFM at 0.5" W.C. The ductwork is only used for AC, for heat there is a boiler and baseboard radiators. ...
Carl's user avatar
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Reduced ducted air flow with heat pump

This post is part of the research I did before installing a heat pump recently, which may help add context: Gas furnace switch to heat pump installation? The heat pump I got installed is ...
dfitzgerald's user avatar
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0 answers
92 views

When is it OK to use "304.6.2 One-permanent-opening method" for combustion air supply?

My basement utility closet currently uses the "Two-permanent-openings method" with one 5" duct from the attic terminating 12" from the floor and another 6" duct terminating ...
Nick's user avatar
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136 views

Using wall cavity to create combustion air duct to attic

I have a two story house with mechanical closet in basement, housing a water heater and furnace. 140k BTU total which requires a 46.6 sq. in. combustion air duct to attic space. This is currently ...
Nick's user avatar
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185 views

Can duct sealant be used around PVC

I have a leaky spot on my ductwork surrounded by PVC exhaust pipes and it's a hard spot to reach so it would be difficult for me to put duct sealant on it without getting it splashed onto the PVC pipe....
MonkeyBonkey's user avatar
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How to size and split hvac ducts appropriately?

I am installing an HRV. A Broan/vanmar/vanee self balancing model. -peak cfm is 160, average cfm will be about 90cfm -It has 6in ports for fresh and return air. -i would like to split both of them ...
Ya Guy Godzilla's user avatar
1 vote
0 answers
288 views

How to route/replace HVAC plenum/trunk lines through a poorly designed foundation wall hole with a gas pipe in the way on the other side

New homeowner of a 1959 constructed house. Surprisingly, only 4 owners (including myself), with the last 2 each having it for about 20 yrs and each seemed to be DIYers - not necessarily choices I ...
DepakoteSprinkle's user avatar
1 vote
0 answers
242 views

Attic HVAC ducts are in the way. What should I do?

Just moved in to a new house back in September and I want to add some pendant lights in the kitchen. Went up into the attic and looked around... The main HVAC duct bisects the attic and I will have to ...
Shrout1's user avatar
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272 views

Is it code to create a return vent that goes directly to a furnace room from the floor above

My first-floor apartment (in a townhouse/brownstone) didn't have a return air duct installed and is instead just sucking in air from the boiler room with a large open return. The architectural plans ...
MonkeyBonkey's user avatar
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1 vote
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446 views

In long run, Which is the best way to connect a flex duct to a Take Off Start Collar?

Please, Please vote up to a right answer. I found in the internet, Connecting a flex duct to take off start collar/ connect still a debatable, I need an answer from people of this community. Thanks! ...
PowerTech's user avatar
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590 views

Ceiling Register Box Insulation and Airtightness - Is this correct?

I'm in the process of making all the ceiling punctures into my attic air tight and better insulated with caulk and spray foam to reduce moisture and my energy costs. However, the HVAC ceiling register ...
SBerg413's user avatar
  • 549
1 vote
0 answers
25 views

Improving HVAC post Remodel

We are living in a house that was originally built in the 80s with a gas furnace and forced air. Prior to our purchase, the house underwent a significant remodel including the addition of two rooms ...
SaunaBuilder's user avatar
1 vote
0 answers
355 views

How to merge extractor fan ducting

I have an kitchen extractor hood that vents air through a 5-inch flexible ducting to a louvred cover in the outside wall. I'd like to add a similar piece of ducting to vent the tumble dryer outside, ...
ConanTheGerbil's user avatar
1 vote
0 answers
133 views

Sharing kitchen hood and kitchen ventilation through one duct

My kitchen currently does not have a kitchen hood, so I'm planning to install it. At the moment there is a ventilation duct, my idea is to connect the hood pipe to the ventilation pipe in the drop ...
Antonio Andrés's user avatar
1 vote
0 answers
35 views

Drafts coming from all floor Heating system ducts. Gaps between sheetmetal and floor have been sealed

I had my heating system, crawl space furnace and leaky poorly insulated sheet metal duct work, replaced a couple years ago with a 96% efficient system. The system was independently tested and ...
Harvey1228's user avatar
1 vote
0 answers
180 views

Closing drywall to duct work

We are trying to convert some garage space into a gym, and one the we’re concerned about is all the gap space between the drywall and the ducting. We want to seal that off as much as possible for air ...
T-House's user avatar
  • 107
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101 views

Concerns with installing 4" Dryer Booster Fan into 7" duct

Our new-to-us home was built in 1850, so there's been a lot of oddball things done to it's guts over time. One of these is the dryer vent duct work that looks to have been installed sometime in the ...
Adrienne's user avatar
1 vote
0 answers
79 views

CAR duct in same bay as electrical wire

I'm going to install a cold air return (CAR) duct through an interior wall that has some electrical running through it. The CAR duct will run vertically, but near the bottom third of the bay there is ...
rothloup's user avatar
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1 vote
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169 views

How do I calculate fan size for a single room exhaust system to reach a desired cfm when restricted to specific duct size/route?

I am wanting to exhaust a sealed room (except for air intake and exhaust). The room is 512 ft3, and due to positioning, orientation, and existing construction, I am restricted to using 6" flexible ...
Steve's user avatar
  • 111
1 vote
0 answers
522 views

Running bathroom vent duct through cold air return

I am remodelling a basement and I noticed that the old bathroom has the vent duct running through the cold air return ( for about 6ft, in and out, the entrance and exit are sealed) and then outside. ...
Theo's user avatar
  • 123
1 vote
0 answers
415 views

Reattach separated range hood duct in attic, without access

I'm refurbishing a kitchen, and removed all the cabinets to refinish them. The small cabinet above the range has the standard rectangular 10"x3.5" duct going through it to exhaust the fan. ...
Carl Raymond's user avatar
1 vote
0 answers
58 views

Studio HVAC Solution

I have an interesting situation where I am in a studio that is approximately 300 sq. ft., and should require ~9,000 BTU/h (3/4 ton) heating/cooling capacity. There are three rooms--A bedroom (~11x8), ...
Hari's user avatar
  • 2,210
1 vote
0 answers
4k views

Bathroom exhaust fan through clay tile roof

I've installed an exhaust fan in an upstairs bathroom and need to vent it through the clay tile roof. (pic attached) The standard 4" pipe jacks and flashings I'm finding at Home Depot don't seem to ...
Kyle's user avatar
  • 31
1 vote
0 answers
4k views

Using PVC pipe for bathroom exhaust fan duct

I have to run a length of about 3 meters of duct (from the fan to the outside), where there will be 2 90° bends. I was going to use plastic flexduct, but I can make the bends bends and some of length ...
Luiz Borges's user avatar
  • 2,325
1 vote
0 answers
2k views

HVAC Return Duct - Joist Panning alternative

Joist Panning(Lining) seems to still be popular. However, a have read in a few places that joist panning is difficult to seal and can pull air from unconditioned spaces. I am looking for an ...
Kalel Wade's user avatar
1 vote
0 answers
187 views

Temporary Remove Flex Duct

I am about to replace a load bearing wall in unfinished basement. There is flexible duct attached to plenum that I need to temporarily move out in order to put the beams in. Do i just need to cut ...
Jeff r's user avatar
  • 11
1 vote
0 answers
128 views

Duct ends behind jacuzzi tub -verify and close or move?

I've wondered for years why our 1st floor bathroom is so hot. I got a temperature gun yesterday and checked, after the heat being on for 30 minutes the inside of the tub read 120. I had to figure it ...
user20127's user avatar
  • 1,211
1 vote
0 answers
31 views

How do you apply the Equal loss friction method when your furnace has extended plenum in two directions?

My furnace has the extended plenum in two directions (one main duct goes to left, the other goes to right) Do I have to calculate one longest path for each of these extended plenums?
MiniMe's user avatar
  • 3,402
1 vote
1 answer
276 views

HVAC turning off below 30 degrees

A bit of a long post but I've tried to be as specific as possible I had a new Goodman HVAC put in Dec 2016 (model GPG1430060M41AB). For the last nine weeks the system has been cutting out when the ...
Susan B's user avatar
  • 19
1 vote
1 answer
3k views

What should we do about asbestos tape on heat ducts?

My daughter just had a home inspection of a home from 1900 and there was asbestos tape noted on the seams of the duct work. What should we do? And I am assuming it is not only on the visible ducts. ...
mary ann herryman's user avatar
1 vote
1 answer
125 views

What cleaners are there in the market to use for Air duct duct cleaning?

My air ducts need to be cleaned: My house is near to the mountains so I' am unable to get a duct cleaning company to come to my house. Can any body suggest me some cleaners used for air duct cleaning?...
Wilburn Weston's user avatar
0 votes
0 answers
15 views

Attic flex run residential

Can I replace three 6” flex duct runs about 5ft long in two bedrooms, and one 10ft run on the third 3 bedroom (3 bedroom, 2 bath house). This is toward the opposite side of the fan end of the run. ...
Bruno's user avatar
  • 1
0 votes
0 answers
31 views

how should I mount this air handler?

I'm installing a new 3-ton heat pump and am trying to plan the crawlspace installation of the indoor unit (1200cfm air handler with heat strips) and its connection to the existing ductwork. These ...
RustyShackleford's user avatar
0 votes
0 answers
25 views

Help identifying wall cap/plug underneath faux fireplace

Background I have an old home from the 1920's. It has a faux fireplace w/ no attached chimney. It appears to be originally added when house was built. There's a 4" galvanized metal cap on the ...
ravishi's user avatar
  • 101
0 votes
0 answers
12 views

furnance vent flue proper attachment

I had a code inspector let me know that my HVAC furnace flue is not properly attached. I have looked all over the internet and i think its a new code requirement in my area in the past few decades (...
gene tsai's user avatar
  • 101
0 votes
0 answers
58 views

Where should I install duct take-offs on a return plenum box?

I have a 5-ton system. My goal is to add an 8" return duct to a 15x9 guest room that has an 8" supply but no return air. When I went up to the attic to review my options, I saw that the ...
yayza's user avatar
  • 1
0 votes
1 answer
51 views

Replacing multiple 6” flexible ducts with rigid

I’m cleaning up ductwork in my basement and want to replace the runs of flexible duct with rigid. Current There is a group of 3 duct runs (6” uninsulated flexible round) that all have very close ...
Ellis Valentiner's user avatar
0 votes
1 answer
50 views

Route return air duct through attic or pantry

I’m looking to get feedback about my options to remediate uneven heating/cooling and poor airflow for two of our bedrooms. Any help or ideas are much appreciated. I'll do my best to provide as much ...
Ellis Valentiner's user avatar