ductwork issue

[ajtalorico]

Hello

I moved into the house I currently live in 4 years ago. Over the past winters and summers two rooms were always hotter in summer, cold in winter, one of those rooms has my thermostat in it!

This is an old house, three stories, with a furnace in the third floor and in the basement.

the ductwork for all of the second floor where the problem is originates in the third floor attic space and then has to travel across the attic down the walls and out to the rooms.

I have called no less than 3 people to resolve the issue without results.

So here is what I have figured out, the main trunk is 12 inches and comes off in the attic, it has a few branches to other rooms that work fine, but attached directly inline to the main trunk is a 10 inch flexible line that travels and then drops down the wall, it then is split in the celing of the second floor to multiple vents that are in the ceiling of the two rooms.

Origionally the 12inch trunk had a 8 inch takeoff installed on it taped to a 10 inch flexible line.

I dont know if that is how it is supposed to be done, but I took it off, and put a 10inch takeoff on instead and reattached the 10inch flexible duct, and then sealed the flexible line back on.

No major change.

These vents produce nothing or next to nothing in terms of air flow and I think this may be simply too far in terms of airflow to get adequate heating and cooling.

A few questions

Are flexible insulated ducts a good product for this application, and do they reduce air flow?

Would a booster fan do the trick installed close to where the duct drops down the wall?

Can I wire the booster fan to the control board humidifier connection and a hot line so it only runs when the blower operates?


thanks for any help

[timebuilder]

Well, my first question would be this. Who are the three people who looked at it, and what did they recommend?

My spider sense is telling me that you did not like what you were told.

Has any work been done by a professional to fix this?

Note: read the rules on DIY. We don't do that here.

[Gib's Son]

Are flexible insulated ducts a good product for this application, and do they reduce air flow?

Would a booster fan do the trick installed close to where the duct drops down the wall?

Can I wire the booster fan to the control board humidifier connection and a hot line so it only runs when the blower operates?


thanks for any help

Flexible duct's are used all the time in resi work and are rarely sized or installed correctly. They are much more restrictive than sheet metal or fiberglass.

A 12 inch duct sounds small for a main takeoff but not knowing anything about the size of the equipment, routing and lengths of runs, what do I know.

Booster fan's can help but should be a last resort. If this is an old house, how well sealed is it and how good is the insulation?

What did the other guys say?

[ajtalorico]

unfortunately the professionals are choosing not to address it.

I have paid three people for service calls at about 100 a pop and 0 results.

not one of them even bothered to go into the attic, although one said he would have someone call me when he saw that there was no airflow coming from the vents. I never got that call.

I may be able to get someone to spend a bit more time, now that the heat is breaking, but I think they are more interested in quick hitters than actually resolving the issue.

im not a novice, I have remodeled 4 homes, and did two additions, wiring plumbing etc, so I am not out of my element, and i feel like I have been screwed over thus the frustration and posting here.

the long and short of it is, whoever installed the system did a bad job, and did not properly calculate the air flow in the bed rooms.

[ajtalorico]

Flexible duct's are used all the time in resi work and are rarely sized or installed correctly. They are much more restrictive than sheet metal or fiberglass.

A 12 inch duct sounds small for a main takeoff but not knowing anything about the size of the equipment, routing and lengths of runs, what do I know.

Booster fan's can help but should be a last resort. If this is an old house, how well sealed is it and how good is the insulation?

What did the other guys say?

the house is very well insulated, in fact an entire house was framed and insulated inside of a double brick home.

windows ect are good vinyl double pane ect.

[timebuilder]

unfortunately the professionals are choosing not to address it.

I have paid three people for service calls at about 100 a pop and 0 results.

not one of them even bothered to go into the attic, although one said he would have someone call me when he saw that there was no airflow coming from the vents. I never got that call.

I may be able to get someone to spend a bit more time, now that the heat is breaking, but I think they are more interested in quick hitters than actually resolving the issue.

im not a novice, I have remodeled 4 homes, and did two additions, wiring plumbing etc, so I am not out of my element, and i feel like I have been screwed over thus the frustration and posting here.

the long and short of it is, whoever installed the system did a bad job, and did not properly calculate the air flow in the bed rooms.

While I appreciate your experiences, the standard we apply here is whether or not someone is an AC pro. I'm sorry to hear that the guys you brought in chose not to address the issue.

I'd recommend checking our map to see if there is a pro in your area who WOULD be willing to help you.

[genduct]

The 12" main that goes to a 10" that used to be 8" sounds like the problem, but you already knew that. Unfortunately the OWL Flex system approach was put forward as the final solution to ductwork design. And what we see is the result of that misguided and misunderstood approach.

Get so real trunk duct and salvage what you can and since you have GC skills the issue of cutting some surgical holes to retrofit a system that delievers shouldn't be a stretch for you.

Stop being polite, tell these guys you need a ductwork evaluation with a sketch of the existing and a proposed "FIX" If they can do that then pay them and stop asking for some general appraisal. The fact that 3 times and you still don't have an answer is your fault. Really surprising since the implication is that you are in the building trades and should know better

[ajtalorico]

The 12" main that goes to a 10" that used to be 8" sounds like the problem, but you already knew that. Unfortunately the OWL Flex system approach was put forward as the final solution to ductwork design. And what we see is the result of that misguided and misunderstood approach.

Get so real trunk duct and salvage what you can and since you have GC skills the issue of cutting some surgical holes to retrofit a system that delievers shouldn't be a stretch for you.

Stop being polite, tell these guys you need a ductwork evaluation with a sketch of the existing and a proposed "FIX" If they can do that then pay them and stop asking for some general appraisal. The fact that 3 times and you still don't have an answer is your fault. Really surprising since the implication is that you are in the building trades and should know better

agreed, I know better. unfortunately most of the service calls were my wife calling them when I was at work, and me giving in to save my eardrums.

now that i have actually gone into the attic I see the issue, and from what it looks like to me, there is no way air is going to make it all the way down that long flexible line,

My idea was a booster fan, but I was also debating running 10inch trunk through that OWL line so at least it is insulated and then use a booster at the furthest point from the main before the duct runs down the wall?

does that make sense?

[energy_rater_La]

women often get the runaround with these issues.
not always, but it happens.
maybe call back when you can be home to go into
attic with ac company.

best of luck.

[tipsrfine]

I'm interested about these 3 companies who came out and couldn't deliver an answer to the complaint. Are they licenced HVAC contractors? Handyman type of people?
Specifically, did the OP here contact 3 different licenced HVAC contractors and neither one of them had a clue?

[timebuilder]

I'm interested about these 3 companies who came out and couldn't deliver an answer to the complaint. Are they licenced HVAC contractors? Handyman type of people?
Specifically, did the OP here contact 3 different licenced HVAC contractors and neither one of them had a clue?

That is my number one question, as well.

[Gib's Son]

The problem with a booster fan is that without a full understanding of what your total external static pressure is and what your blower is capable of it's a stab in the dark as to sizing it properly....and it's a bandaid to what is really going on.

You need a pro that can evaluate, and calculate what size ducts need to be there. None of this "a six inch duct is only good for 100 CFM and an eight is only good for"...blah blah blah. The longer the duct duct runs, the more fittings there are, twists and turns, the greater your total external static pressure will be. A 12 inch take off may be fine if it's only 4 feet but if it's 15, that's another story. It's not the size of the duct that counts, it's the sum off all frictional loss and matching it against the manufactures blower wheel curve that counts.

And don't use flex off the main trunk if at all possible. Go with spiral or rectangular sheet metal.

Did you do what TB suggested and look at the contractors map?

[ajtalorico]

the more i read here the more i think my situation is a total disaster.

there is flex everywhere, in fact its predominantly flex even the main takeoff is flex as far as I can see, and I think this is because of space limitations.

then there is a metal trunk inside it ,then the flex again.


I imagine its a lot easier to manipulate flex than galvanized in a tight place, and thus the shortcut of flex.

[tipsrfine]

I'm interested about these 3 companies who came out and couldn't deliver an answer to the complaint. Are they licenced HVAC contractors? Handyman type of people?
Specifically, did the OP here contact 3 different licenced HVAC contractors and neither one of them had a clue?

?

[ajtalorico]

one for certain was a HVAC, because that was the one i told my wife to call.

he never went into the attic, he removed some dirty air cleaners, left me with a bill for $95 and was supposed to have someone follow up. no one did

dont know what the other guys were to be honest, but they didn't do anything.

i dont think this is a rare or even complicated problem, my limited knowledge and 20 minutes with a flashlight and I think I figured it out.

I emailed the HVAC company and asked them to come back and take a look after listening to what you guys said.

i think there is a pretty big issue in terms of workmanship, or just short cuts

[timebuilder]

Depending on the age of the installation, it may have been done at at time when rules of thumb were used instead of calculations.

Where are you located?

[ajtalorico]

Depending on the age of the installation, it may have been done at at time when rules of thumb were used instead of calculations.

Where are you located?

Im in Western Pa, I think it was done in 2003..

where would I look to find out who did the work, a mark or signature of sorts?

[timebuilder]

If you could contact the first owners, you could ask. But, they may not know. If it is a part of a development, the the company may still know who the subs were.

It's probably better to make some calls and ask for someone to do a heat load calc and a manual D. If they say, "what's that" then thank them for their time and call the next HVAC co on the list.

Someone in your area knows how to do this. How far are you from Pittsburgh?

[lynn comstock]

....Are flexible insulated ducts a good product for this application, They are a good product. and do they reduce air flow? Yes, compared to smooth sheet metal of the same size.

Would a booster fan do the trick installed close to where the duct drops down the wall? Mabybe.

Can I wire the booster fan to the control board humidifier connection I don't know. and a hot line so it only runs when the blower operates? There are ways to make a booster fan run with the system fan.

Your idea could work or it could fail, it depends on the fan chosen and the proper installation of the fan. That is the rub.

[genduct]

agreed, I know better. unfortunately most of the service calls were my wife calling them when I was at work, and me giving in to save my eardrums.

now that i have actually gone into the attic I see the issue, and from what it looks like to me, there is no way air is going to make it all the way down that long flexible line,

My idea was a booster fan, but I was also debating running 10inch trunk through that OWL line so at least it is insulated and then use a booster at the furthest point from the main before the duct runs down the wall?

does that make sense?

You "system" doesn't deliver, and probably never has So do you have a claim against the person who sold you the home and didn't disclose that info OR the original builder/ subs whose insurance is always going to be available since it wasn't done right in the first place.
That only means you need to document the current situation and the fix, which as I stated earlier, is a real trunk duct with flex branches that could be flex connections salvaged from you current install.