Questions tagged [ducts]

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2answers
97 views

Is there any reason that plumbing can't be adjacent to a heating/cooling duct?

I'm installing a utility sink and the only place to put the plumbing (if it's going to be right under the sink) is either directly behind or infront of this vent... Is there any reason not to put it ...
3
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1answer
406 views

Can a motorized damper be installed inside existing ductwork?

My HVAC system consists of a fan, furnace, compressor-driven AC, and evaporative cooler. The problem is that there is a large air volume used only by the evaporative cooler that is generating a lot of ...
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1answer
154 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 ...
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15 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 ...
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44 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 ...
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0answers
43 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 ...
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1answer
99 views

How can I prevent makeup air vents from exhausting conditioned air?

The utility room has two 8-10 inch ducts running to it from the exterior of the home. There are also three fireplaces in the home, and we have noticed that occasionally the house smells like smoke, ...
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0answers
44 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 ...
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0answers
87 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 ...
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1answer
152 views

Is there a way to change the location of HVAC air filter location?

We bought the house recently. Heating system was recently installed by the previous home owner. I cannot believe they did not think of this but the place for filter is inside the furnace. The problem ...
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0answers
123 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. ...
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0answers
242 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. ...
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52 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), ...
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0answers
2k 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 ...
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0answers
3k 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 ...
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0answers
101 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 ...
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0answers
70 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 ...
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0answers
107 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 ...
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0answers
26 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?
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0answers
225 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 ...
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2answers
294 views

Is there some type of coating I can use to prevent condensate on my HVAC ducts?

I'm getting a lot of condensate on my HVAC ducts that run though my first floor (and HVAC blower) especially in July / August when humidity levels are outrageous (in NJ). The 1st floor space space is ...
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1answer
2k 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. ...
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1answer
92 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?...
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22 views

Should I move an HVAC vent to the ceiling or on the opposite interior wall?

The below picture shows the current position of the vent (the white area over the sink). The blue patch above the toilet is a small window. The plan is to relocate the bath tub and position it along ...
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0answers
25 views

How to calculate whether it's worth turning on a fan to bring warmer air to a heat pump hot water heater?

I have 4 new Rheem 50 gal heat pump hot water heaters being installed in the basement of my home/multiunit property that is a 4-unit building (one heater per apartment). Generally speaking, the attic ...
0
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1answer
30 views

Can this stack air duct be removed to tear down small wall?

I have an appointment with the HVAC supply business that installed the furnace 2 years ago but it is months away. My question is can I remove this wall to make my shower bigger? Through research I ...
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0answers
26 views

Help reroute cold air return

I am working on opening up space between my lobby (on the right side of the wall) and the dining room area (on the left side of the wall). The section of the wall that is used as cold air return ducts ...
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0answers
28 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 ...
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0answers
19 views

Range Hood Ductwork, ceiling to roof offset issues

I'm installing a new chimney style hood, with a 6" exhaust that vents through the ceiling. The fan I'm replacing has an 8" pipe, which vents out of the roof of the house. The issue that I'm having is ...
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0answers
42 views

CFM ratings of inline duct fans far exceed the ratings for their intended duct sizes. What are we to make of this when designing a system?

My garage is 25×29' with 10' ceilings, so 7250 cf. I'm hoping to be able to turn over the air every 3 minutes or so, so aiming at using 2 fans rated at a total of 2400cfm. The fans I'd like to use ...
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0answers
11 views

Replacing flexible.duct work on AC unit

I purchased the correct size flexible duct for the air supply, but was unaware that the return side is 2 inches bigger. Since I am unable to purchase the bigger size until next week, is it safe to run ...
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0answers
126 views

Seal old ductboard from inside with duct mastic?

For the next few days, I have what appears to be an opportunity to easily and cheaply make a small improvement to the overall airtightness (or nearly complete lack thereof) of my house's 40 year old ...
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143 views

Best way to retrofit a dyer vent duct in 2x4 interior wall

My washer and dryer are located on the second floor of a two floor townhouse (crawlspace foundation). It's basically a closet that fits the two machines only, with very limited space front to back ( ...
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1answer
74 views

Axial or centrifugal fan for short run out of kitchen?

I'm researching replacements for a broken extractor fan in my kitchen. It is wall mounted and runs through the wall straight outside, no long ducting involved. The current (broken) fan is the ...
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0answers
30 views

Using existing hot water vent for extraction

I have a room in the basement with equipment (computers) that gets really hot. There is an ac vent but the thermostat is nowhere near the room. Also in an alcove is the hot water heater behind a ...
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0answers
34 views

Bought a home, return air vents on ceiling have R19 insulation shoved in them?

Checking filters and seeing what needs to be replaced, I opened the return air grate on the ceiling and what I find inside is a hunk of R19 insulation. Seems it should be some proper return air filter ...
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0answers
33 views

use of conduit for ducts

I need 2" ducts in this room I'm building. Flexible ducts and conduit are about the same price. I have high heat requirements. Can I use conduit for ductwork? What are the pros / cons? Thanks
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0answers
134 views

Round metal duct leaking water at crimped joint

Noticed a water leak stain in my ceiling in the drywall. Cut a hole and noticed water drops dripping from the joint of a metal round air duct. This duct leads to an external air vent on the side of my ...
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0answers
24 views

How to fix noise in my bedroom since change of furance/ac but not air ducts?

I had furnace company back out and he told me it is probably a problem with a damper but it would be hard to find out where. It is only loud in my room on second floor but not in other bedroom next ...
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0answers
156 views

8 in thimble, 6 in pipe

I just installed a wood stove in the addition I built for my trailer. My father-in-law insisted on going and buying me an 8 inch thimble for my stove pipe to run through the wall. My stove pipe is ...
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0answers
233 views

how to deal with oversized furnace

I recently got a new furnace for our 1200 sqft house in Denver CO. We are planning on adding a second story in a year and I was going to wait until we did that to replace the furnace. Then the furnace ...
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0answers
487 views

Increasing exhaust fan duct size

I have a bathroom exhaust fan that has a 3 inch duct outlet. However, I would like to use a 4 inch insulated flexible duct. Is there an adapter I can use to accomplish this or do I have to first use ...
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0answers
32 views

30 y.o. air pump troubleshooting. Where do I start?

500 sq.ft. apartment, 2nd floor, 32 y.o. through the wall, ducted air heat pump. The pump is installed in a closet next to the apartment (separate entry), and the air ducts spread from there along the ...
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0answers
67 views

Cut cross-break duct?

I bought a piece of rectangular duct from my local home supply store but it is slightly larger than what I need. The ducts they sell are cross-broken instead of beaded. Is it ok to cut down a duct ...
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0answers
46 views

Central heat ducts(the ends that are attached to registers) in attic not securely attached to attic floor/room ceiling. How to secure?

When I removed the registers in the ceiling of our house I noticed that the ducting in the ceiling was totally loose. They are not secured in any way. The two screws of the register was what was ...
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0answers
61 views

No insulation behind duct work, basement wall

Insulating my basement with 1.5" thick XPS foam to achieve R-7.5. Great. All things happy. Except I ran into an issue. My rectangle ducting (the main trunk) line actually stops a 1/4" away from my ...
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0answers
276 views

Noisy ducts, problem with insulation?

I have what I'm coming to believe is a unique noise issue with the HVAC ducting in my house. I've spoken to four different professionals and they are all somewhat dumbfounded. The problem is that my ...
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0answers
47 views

Basement duct installation with fire sprinkler pipe

Can I install a metal HVAC duct with register into the same ceiling joist bay as an orange fire sprinkler pipe, parallel to it? The sprinkler pipe has 2 heads on it.
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0answers
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 ...
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4answers
7k views

How to fill / seal in-slab hvac ductwork?

My house is built on a slab. Within the slab are "channels" which act as ducts for the HVAC system. I assume it is partially lined with metal but based on photos from an HVAC-cleaner, it's hard to ...