Fiberglass Liner in Trunk Line

[jeffer949]

So my I bought a house a few months ago and have been spending the past few months remodeling it. Finally got moved in 2 weeks ago and my wife has been coughing and sneezing and has a sore throat when she wakes up. I put this up to her being sick which she was when we moved. She had wanted to have the ducts cleaned and well I don't think it does much for indoor air quality and money has been evaporating quickly from the remodel. So it was never done.

Well, last night she asked if I would put my snake cam down the vents to see how dirty they are. I did and the vent lines did have some dust but nothing out of the ordinary for a house built in 1994 and none is construction debris or dust like she is thinking. I keep going down the vent line and get into the opening to the trunk and I see fiberglass matting at the joint. Go farther in and I see the whole trunk is lined with it. And it has a lot of dust and dust bunnies on it. Again not from construction but still dusty. The furnace was replaced under warranty before we purchased the house. And its a 2 stage Lennox unit that puts out some air. I think the higher velocity air of the new furnace is dislodging the dust in the trunk line and is going in the house. The fiberglass looks to be intact and not going anywhere but my wife will not be ok with it how it is.

My wife is very sensitive to smells and dust and stuff and I had no idea this was in the trunk line. I've never seen it in the supply ducts before, only in the return.

From my understanding its not smart to have these cleaned as it can damage and make the fiberglass air born. I've heard about coating it but I don't think that would go over well either. So I'm left with having it replaced or replacing it myself.

I'm sure I can do the work but time is of concern. It is located in a 3-4 ft tall crawlspace. It is 35 feet long (7 five foot sections) and it has 9 vent lines I would have to make holes and hook up the lines.

Any pointers on doing this? I know I could find everything online somewhere on how to join the sections of duct work but if someone could point me in the right direction I would appreciate it.

Thanks

 

[zmaxmotorsports]

So my I bought a house a few months ago and have been spending the past few months remodeling it. Finally got moved in 2 weeks ago and my wife has been coughing and sneezing and has a sore throat when she wakes up. I put this up to her being sick which she was when we moved. She had wanted to have the ducts cleaned and well I don't think it does much for indoor air quality and money has been evaporating quickly from the remodel. So it was never done.

Well, last night she asked if I would put my snake cam down the vents to see how dirty they are. I did and the vent lines did have some dust but nothing out of the ordinary for a house built in 1994 and none is construction debris or dust like she is thinking. I keep going down the vent line and get into the opening to the trunk and I see fiberglass matting at the joint. Go farther in and I see the whole trunk is lined with it. And it has a lot of dust and dust bunnies on it. Again not from construction but still dusty. The furnace was replaced under warranty before we purchased the house. And its a 2 stage Lennox unit that puts out some air. I think the higher velocity air of the new furnace is dislodging the dust in the trunk line and is going in the house. The fiberglass looks to be intact and not going anywhere but my wife will not be ok with it how it is.

My wife is very sensitive to smells and dust and stuff and I had no idea this was in the trunk line. I've never seen it in the supply ducts before, only in the return.

From my understanding its not smart to have these cleaned as it can damage and make the fiberglass air born. I've heard about coating it but I don't think that would go over well either. So I'm left with having it replaced or replacing it myself.

I'm sure I can do the work but time is of concern. It is located in a 3-4 ft tall crawlspace. It is 35 feet long (7 five foot sections) and it has 9 vent lines I would have to make holes and hook up the lines.

Any pointers on doing this? I know I could find everything online somewhere on how to join the sections of duct work but if someone could point me in the right direction I would appreciate it.

Thanks

It's probably duct board/sound deadening in there.
Keep your filters changed on a regular basis,that should take care of the problem.

 

[readhead]

Could be duct board or is it metal duct with liner inside? Keeping the filter changed is important and a electronic air cleaner might help.
Your wife's problems may have nothing to do with the heating system. There may be other causes such as mold. It would be useful to have an environmental testing company come out and test the house and see what is up.
The heating system is easy to blame because it is moving air. Duct liner has been used in commercial buildings for over sixty years with a proven track record.

 

[ripperd]

What are the bedroom humidity levels? low humidity will also cause scratchy throats and cold-like symptoms.

 

[brewchief]

I would second looking at humidity levels.

If the house was built in 94 and the furnace was replaced under warranty it probably had a Pulse originally, they needed the liner inside the duct for sound purposes.

 

[jeffer949]

I would second looking at humidity levels.

If the house was built in 94 and the furnace was replaced under warranty it probably had a Pulse originally, they needed the liner inside the duct for sound purposes.

It was a Pulse furnace. the humidity levels are in the low to mid 40's so not high but not low either.

All the advice about keeping a good filter installed is great and we currently have the lennox 20x25x5 air box and a the correct sized merv 13 filter. This does not help the fact that there is already tons of dust in the ducts already. My issue is not the fiberglass mat. Its that it trapped tons of dust for years and now we have a stronger furnace blowing more air and its dislodging it and putting it into the house.

We have had the furnace off for 2 days now and it smells better and the dust has gone down and my wife has stopped coughing.

I guess I was looking more for advice on doing the actual work. I have since found some videos on how the pieces connect and found a place that has the correct size duct. My wife wants to wait on a quote from a professional but every one I called is busy so we are just waiting.

 

[brewchief]

Tonight when i get some time i will be able to offer some practical advice on replacement of the ductwork.

Sent from my XT1254 using Tapatalk

 

[readhead]

Replacing the duct is pretty simple. Remove the taps and remove the sections of duct. It is probably connected with S's and drives. Bend up one end of the drive and slide it off on two sides then pull the duct out of the S. Reverse for install of new duct. Cut holes for taps. Install taps. Since the duct is not in a conditioned space you will need to wrap the duct with insulation.

 

[zmaxmotorsports]

It was a Pulse furnace. the humidity levels are in the low to mid 40's so not high but not low either.

All the advice about keeping a good filter installed is great and we currently have the lennox 20x25x5 air box and a the correct sized merv 13 filter. This does not help the fact that there is already tons of dust in the ducts already. My issue is not the fiberglass mat. Its that it trapped tons of dust for years and now we have a stronger furnace blowing more air and its dislodging it and putting it into the house.

We have had the furnace off for 2 days now and it smells better and the dust has gone down and my wife has stopped coughing.

I guess I was looking more for advice on doing the actual work. I have since found some videos on how the pieces connect and found a place that has the correct size duct. My wife wants to wait on a quote from a professional but every one I called is busy so we are just waiting.

The dust will make its way back through the system eventually and get caught in filter.

 

[rburke65]

Why us it necessary to keep reposting the previous responce ?

 

[zmaxmotorsports]

It was a Pulse furnace. the humidity levels are in the low to mid 40's so not high but not low either.

All the advice about keeping a good filter installed is great and we currently have the lennox 20x25x5 air box and a the correct sized merv 13 filter. This does not help the fact that there is already tons of dust in the ducts already. My issue is not the fiberglass mat. Its that it trapped tons of dust for years and now we have a stronger furnace blowing more air and its dislodging it and putting it into the house.

We have had the furnace off for 2 days now and it smells better and the dust has gone down and my wife has stopped coughing.

I guess I was looking more for advice on doing the actual work. I have since found some videos on how the pieces connect and found a place that has the correct size duct. My wife wants to wait on a quote from a professional but every one I called is busy so we are just waiting.

The sledge hammer would've been a better name for them.
Them and old York condensing units were pretty ease to detect from a distance.

 

[brewchief]

For replacement start by taking down the old duct, start at the end away from the furnace and disconnect any round pipe runs then pull the drives off and remove any screws that are hanging it.

I recommend replacing the top takeoffs, you can unbend the tabs but for what we pay for them it's not worth our time.

You will have some ductwork at the furnace end that is either going to have to stay or you will have to have built, you may be able to remove the liner from this and get it clean enough to keep.

I would use a set of red offset snips to cut the new holes, a set of dividers makes marking the duct easy, if you are using round top takeoffs most of the time the hole size needed is one size larger then the pipe size, you will need a 7" hole for a 6" takeoff. A large screwdriver held at an angle and hit with a hammer or the side of the snips will create a starting hole. If you measure carefully it goes pretty quick.

I would buy some duct mastic and seal each takeoff as I went and then all the seams once it's all done.


You have said that the new furnace moves more air, do you by chance know any model numbers from the old? Can you post model numbers of the new along with the model numbers on the A/C unit? There is a decent chance that the new furnace might not be set up properly and may need a blower speed adjustment.

 

[JRC3]

Probably prefab or fabricated duct board.

I've seen it before while working on a double-wide. I can't believe they allow it in HVAC where moisture can develop and mostly because of the dust that can never be completely cleaned.

Your crawlspace is as tall as mine and I took down every other section of my 30' trunk as well as ever branch and thoroughly vacuumed. All in all it took me about 8 hours and replacing yours would be about the same amount of work. With a helper you could do that much quicker. My duct cleaning. https://www.garagejournal.com/forum/showthread.php?t=344629&highlight=duct

Why us it necessary to keep reposting the previous responce ?

Well, it lets everyone know what is being responded to. Many don't do it around here and it's even worse when it was from pages ago. Though...It is better forum etiquette to use the ^ sign to respond to the very last reply. Sometime ^^ to referer to the reply before the last.

 

[zmaxmotorsports]

Why us it necessary to keep reposting the previous responce ?

So they know what post you're responding to?

 

[shedfullatools]

We have filters installed in every floor box as well as at the furnace, made a huge difference in the stuff that blows out after it hasn’t been used in a while. You buy the stuff in a sheet or roll and it looks just like the filters you put in the furnace. Cut it to size and push it in under the floor grate.


Sent from my iPhone using Tapatalk

 

[PWC Repair]

My wife wants to wait on a quote from a professional but every one I called is busy so we are just waiting.

It's like most other skilled trades. Go to the HVAC house where they buy their stuff. Ask the counter guy for a dependable guy that does side jobs. They will have a name and number. I would never put ductliner inside the duct for exactly this reason (dust, mold, etc).

 

[jeffer949]

Well I did it myself this weekend. Still have a little bit to insulate. One third the cost of the quote. Ill post some pictures once I'm done.

Sent from my SM-G950U using Tapatalk

 

[Ohmthis]

Good deal! Was it as bad or easy as you thought? Sometimes people flip out when the work is pretty easy.

 

[jeffer949]

For replacement start by taking down the old duct, start at the end away from the furnace and disconnect any round pipe runs then pull the drives off and remove any screws that are hanging it.

I recommend replacing the top takeoffs, you can unbend the tabs but for what we pay for them it's not worth our time.

You will have some ductwork at the furnace end that is either going to have to stay or you will have to have built, you may be able to remove the liner from this and get it clean enough to keep.

I would use a set of red offset snips to cut the new holes, a set of dividers makes marking the duct easy, if you are using round top takeoffs most of the time the hole size needed is one size larger then the pipe size, you will need a 7" hole for a 6" takeoff. A large screwdriver held at an angle and hit with a hammer or the side of the snips will create a starting hole. If you measure carefully it goes pretty quick.

I would buy some duct mastic and seal each takeoff as I went and then all the seams once it's all done.


You have said that the new furnace moves more air, do you by chance know any model numbers from the old? Can you post model numbers of the new along with the model numbers on the A/C unit? There is a decent chance that the new furnace might not be set up properly and may need a blower speed adjustment.

Replacing the ductwork was actually pretty easy. Its insulating it that takes the most time. I cleaned the round vents with a duster ball hooked up to my drillhttps://photos.app.goo.gl/2XX4Rz0ep871tfk32 and then rinsed them out. The elbows were not the bending tab type. They had section that pivoted up and locked them in place. I did use duct sealant here and at every other joint. As far as cutting the holes I bought a sheet metal whole cutter from menards. Worked great.

The box under the furnace along with the transition box from it to the trunk line was lined also. I removed all the liner and scrubbed and cleaned it really well and vacuumed it. The liner directly under the heater/AC showed signs of water dripping on it. Im going to make sure I clean the condensate traps before it gets warm outside to make sure they are clear and can flow well.

Thanks for the advice on this also. The furnace was a 80,000 btu Pulse 21, The new one is a EL195DF070XE48B Lennox furnace. I don't have the model of the A/C but it is a 4 ton unit. I can get it tonight though.

Thanks

 

[jeffer949]

Here is my ac info. The furnace was a qsr21q.

Sent from my SM-G950U using Tapatalk