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1answer
45 views

How can I get better HVAC airflow?

I recently purchased my house which was a new construction. Several of the vents are getting poor airflow but the installation company simply said it was normal but I suspect otherwise. I recently ...
1
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1answer
14 views

Duct sizing impact on flow

We have a ranch with a wood fireplace in the living room. It's fantastic at heating the main living area, but the bedrooms down the hall get left in the cold. I'm going to install insulated flexible ...
2
votes
1answer
53 views

90 degree angle in air conditioning ducts, should I avoid them?

I have forced air at my home and air ducts run pretty much straight. However I want to add bathroom in the basement and because of low ceiling hight, the main air conditioning duct has to be re-routed ...
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2answers
23 views

How to install small damper in a duct?

I need to install a Honeywell 10x10 damper into a 11x11 duct. Options that I came up with: build an adapter to reduce duct to 10x10 (alternatively I can use 12x12 damper and build adapter to ...
3
votes
1answer
40 views

Bedrooms aren't being heated as well after new furnace

When my bedroom doors are closed the room is cold. We replaced our furnace about 5-10 years ago and the repair person said we didn't need as big a unit as we had before and every since then it feels ...
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1answer
26 views

Repairing a rip in my hvac vent

A small section of canvas fabric connects the duct coming out of my furnace to the rest of the house. I noticed that there's quite a large rip in this fabric. Would it be best to use standard foil ...
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1answer
46 views

Attic Insulation

I have Insulated AC flex duct work in my attic. Am I correct in that since its insulated already if I lay insulation over the duct work it is fine as long as the duct work is sealed properly? I have ...
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0answers
48 views

new furnace hurts eardrums

I just got a new furnace in my 800 sq. ft apartment. Single stage 80% efficiency 40K BTU Coleman. It seems much louder than my old one. The burners and the blower. And when I walk past the (single) ...
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2answers
94 views

How to seal HVAC ducts running through old window to addition?

My house has a small addition that was added by the previous owners. They ran the HVAC ducts through an old window and some of the block: The rectangular section in the window should be easy ...
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3answers
1k views

How can I stop our duct work “pinging” at night?

I'm in Canada, and our home is a bit older, ~20 years, and the duct work seems to be making a rather loud "pinging" noise at night. I assume this is due to colder weather in general, and the hot air ...
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0answers
27 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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2answers
59 views

Replace or wash this furnace filter?

My mom's furnace has ductwork until right next to the furnace, where the return air instead goes into an obsolete electronic air cleaner that is basically as big as the furnace itself. The issue is ...
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0answers
17 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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1answer
44 views

Does cold galvanizing compound restore the rust protection of a galvanized duct?

The house is a ranch built on slab on grade with a newer furnace in a downflow configuration with A/C. The in-floor clay tile supply lines are in good shape and clean. The original 60 year old ...
0
votes
1answer
77 views

What is this 6" vent coming out of the main furnace trunk going under my deck for?

I have a 6 inch round duct that comes out of the main trunk about 5 feet from the furnace. It runs through the basement and outside the house (under the deck). What is this? The furnace also has 2" ...
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0answers
55 views

Older home with no AC plenum…replace our entire AC system as suggested?

We have an older home that has a large living-area/fireplace room; the AC unit sits over it in the attic. Earlier this year, in that room, we noticed a crack beginning to form in the ceiling sheet ...
4
votes
2answers
204 views

How to repair buckled duct work inside wall?

Update I think the duct is actually fine. The duct connects to a register that is shared by two rooms. When heating, one room is gets hot, while the other is cool (not too cold). I think the problem ...
3
votes
2answers
2k views

How can I quiet a bathroom exhaust fan that became loud only after the duct was added?

I had a fan added in my bathroom. Surprisingly there wasn't one at all. When the fan was first installed they had it venting into the ceiling. It was a .5 sone fan and you could hardly tell that it ...
0
votes
1answer
58 views

When installing rigid dryer vent and connecting pieces

When installing rigid dryer vent and connecting pieces together do I use foil tape or those circle things you put on outside with a screw to tighten? Also is it a good idea to use duct connectors ...
3
votes
2answers
230 views

Flooded HVAC ducts

I own a house (Built in 1966) on a shallow hillside, around which recent rain has caused complete ground saturation. On my bottom floor, which is on a concrete slab, the three floor vents were ...
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2answers
44 views

Finding air leaks in ducts

I've been sealing the ducts in our basement with mastic. I've done a decent job, but I'm trying to find every leak in the basement, where it's accessible. For instance, I stand on the ladder in one ...
1
vote
1answer
592 views

How to run duct work for basement dehumidifier?

Our basement is partially finished, approximately 50/50 in terms of square footage. It was used as a mother-in-law suite at some point by a previous owner. The finished rooms are air ...
0
votes
1answer
595 views

Duct static pressure vs ambient air pressure

I've read that air handlers are typically rated for 0.5 iwc. Doing a simple conversion, this comes out to about 125 Pa. Is this with reference to the ambient air pressure? So, if I had an absolute ...
0
votes
2answers
330 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 ...
1
vote
2answers
111 views

Is having a branch off the end of main heating HVAC duct bad and if so, why?

Question: Is having a branch off the end of main heating HVAC duct bad and if so, why? Background: A heating and cooling contractor sales representative came to my home today. He saw the situation ...
1
vote
1answer
128 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. ...
1
vote
1answer
832 views

Appropriate register for duct size?

So I asked a long-winded version of this question in another thread, but haven't really received any good responses yet. I'm going to condense and try again... There is an 8" duct feeding a 6x12 ...
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votes
0answers
214 views

Would increasing the size of the A/C duct for my kitchen improve cooling?

As part of an ongoing kitchen project, I'd like to relocate the existing a/c register in the ceiling (which is located next to an interior wall) to the center of the room and upsize the duct (and ...
1
vote
1answer
122 views

Sound proofing HVAC ducts

We have an HVAC system in our house where the duct work is all sheet metal with no insulation on the interior of the ducts as all of it is buried under inches of foam roofing insulation. Works great. ...
1
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0answers
53 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 ...
4
votes
2answers
70 views

Solution for fiberglass ducts that have collapsed in basement?

I have two furnaces in my house, one for the basement and one for the rest of the house. I noticed that while using the basement furnace this winter that no air was coming out of any of the basement ...
3
votes
1answer
740 views

Dryer vent passing through two wooden beams. Is it safe?

I have a dryer vent that exits the house wall through two wooden beams. The vent is built using two corner rigid pieces and one long rigid aluminum piece. The long rigid piece is the one that passes ...
1
vote
2answers
3k views

HVAC Duct options in floor joists

I will explain what I would "Ideally" want. I would like the HVAC in the basement ceiling to Not require a soffit. Plumbing seems possible because the holes for the most part will be small enough to ...
1
vote
1answer
170 views

Is my HVAC system unbalanced?

I bought a home back in August and the previous owner had a new 3-ton HVAC system installed. Basically right now the HVAC is located in the upstairs hallway, and the way the duct is set up is there ...
2
votes
3answers
1k views

Are sheet metal screws required for connecting round duct branches?

I've finished dry-fitting a new branch (6-inch round) from the main furnace duct to a new register. I've supported each section of duct with metal strap and have begun taping all connections with ...
4
votes
1answer
631 views

Adding vents to duct?

My house has forced air HVAC. When I finished the basement, I used a closed cell foam insulation that worked very well. The basement will get only 8 degrees cooler than the first floor during a time ...
1
vote
0answers
27 views

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

My house is near to the mountains so I' am unable to get any help from Air duct cleaning Denver experts as they are unable to come over my house. Can any body suggest me some cleaners used for air ...
3
votes
1answer
220 views

How can I remove ductwork that is butted against a foundation wall?

I need to remove the existing ductwork in my basement to install insulation behind it. I'd like to do it without destroying the ductwork. The vertical duct is right against the foundation, so I can't ...
0
votes
1answer
654 views

Will splitting a duct to extend HVAC to an addition cause problems?

I'm building a 15 x 26 addition off of current family room to use as a music room. The family room has 2 vents(registers) where the family room meets the new room, and because of convenience they ...
1
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0answers
21 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?
1
vote
1answer
186 views

Why would only 1/3 of my registers be blowing warm air?

I have a Coleman gas furnace in a wall space in my house which somehow shares the blower on my a/c unit on the roof because it turns on when furnace is called to start, though it does bump up after a ...
0
votes
2answers
1k views

How do I calculate CFM for a structure?

This is for calculating the CFM (cubic feet per minute) of air that the blower needs to move in order to compensate the total heat loss (ventilation,infiltration,heat loss through walls, windows, ...
0
votes
2answers
455 views

Can I move second-floor duct-work from the floor to the attic

I have a two story home that sits on a slab. There is some duct work that runs through the slab. I have some duct work that runs through the ceilings of the first-floor and points towards the floor of ...
0
votes
1answer
98 views

A professional to test asbestos safety in furnace ducts

We live in a rented house with an old furnace duct system (probably 1960's). There is asbestos-containing duct-wrap all around the ducts, and it starts to crumble in some places (it's located in the ...
0
votes
1answer
115 views

How can I build custom air ducts for an in-wall heater?

I have a in-wall heater just like this one: It sucks cold air from lower part of vent, heats inside, and blows it out in the upper part of the vent. Now I have the basic problem of putting a ...
0
votes
4answers
284 views

Is it safe to use an HVAC system even though the duct wrap contains asbestos?

In our rental house the furnace ducts are very dirty. We brought an expert to clean it, but he said he just won't do it because the tape around the ducts (in the attic) is probably asbestos. After ...
2
votes
3answers
6k views

Can I cap the air return in my unfinished basement?

I noticed today that there is a massive air return in my unfinished basement. The opening is about 2 meters from the blower, and as large in diameter as the return duct coming from the upstairs. This ...
1
vote
0answers
151 views

Can I cut out the sill plate to pass a duct through a load bearing wall?

I need to pass an HVAC duct through a load bearing wall into the basement below it. I can't seem to find a code reference in IRC for what I am allowed to do with respect to notching or cutting away ...
0
votes
2answers
73 views

Is it possible to create a better temperature controlling system?

I have a two story 2.5k sq ft house with a varying degree of temperature throughout the house. The main problem is that the air coming out of vents are very weak if almost nil. Only the living room ...
0
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0answers
68 views

Lint when running AC

There seems to be a lot of lint when I run my AC unit. I have recently replaced the filter and made sure that the filter is put in correctly. What could be the issue?