Welcome to City-Data.com Forum!
U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > House
 [Register]
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
Reply Start New Thread
 
Old 06-21-2018, 06:48 AM
 
5,938 posts, read 4,671,889 times
Reputation: 4630

Advertisements

I'm being told by an installer that gave me a quote that I need new ductwork. He didn't explicitly say the ductwork is bad or in a state of disrepair. It seemed to have more to do with the type of system he'd be installing needs different ductwork (larger or smaller size? I don't know?). He kind of looked at me funny when I said "How about we get a system that works with what I got?"

I guess this is where I'm confused. Is it that new HVAC systems (he'd be replacing a unit from the 90s) simply can't use "old ductwork" for whatever reason? He did point out that the way things are right now, the volume of air being moved into one room (a bathroom) is equal to the volume of air being pushed into the smallest bedroom.

So sure, there's likely some inefficiencies with old ductwork, but to replace what is currently there that seems to do the job for about $5000 seems unnecessary.

But maybe I'm missing something here. What are valid reasons that I'd need to replace my ductwork? If it matters, we are talking about a split system (condenser outside, air handler in the attic, ducts in attic).

Last edited by dspguy; 06-21-2018 at 06:59 AM..
Reply With Quote Quick reply to this message

 
Old 06-21-2018, 07:02 AM
 
Location: The Triad
34,091 posts, read 82,482,448 times
Reputation: 43648
Quote:
Originally Posted by dspguy View Post
HVAC: Is it necessary to replace ductwork?
I hate these sorts of absolute questions.
CAN IT be appropriate to (whatever)... ? Yes it can.

Quote:
It seemed to have more to do with the type of system he'd be installing needs different ductwork
He kind of looked at me funny when I said "How about we get a system that works with what I got?"
He didn't explicitly say the ductwork is bad or in a state of disrepair.
Whether YOU might need ductwork changes or not (most will)...
and whether the totality of changes might warrant just starting over or not (as it will sometimes come to)
you ABSOLUTELY need a contractor who you have an objective reason to trust and above all other considerations.


That might be the real question here.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 07:32 AM
 
5,938 posts, read 4,671,889 times
Reputation: 4630
If only I could go back and change the thread title. Later on in my post I said:

Quote:
What are valid reasons that I'd need to replace my ductwork?
Maybe that should be the thread title instead.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 08:21 AM
 
4,690 posts, read 10,344,851 times
Reputation: 14882
I went through this a couple years back. The short of it is that the system design has changed (probably with the help of whatever HVAC group that ensures more work/money for installers ~ planned obsolescence). It was that the blowers pushed higher velocity through smaller ducts and systems now push lower velocity (but more volume) through Bigger ducts. Use a modern fan with the older ducts and you put additional stress/strain on the fan which will lead to a shorter life and, I think, lower efficiency.


My installer said it was more important for the Return duct to be the right size than the feed, so that was the only one he replaced.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 08:41 AM
 
5,938 posts, read 4,671,889 times
Reputation: 4630
Quote:
Originally Posted by Brian_M View Post
I went through this a couple years back. The short of it is that the system design has changed (probably with the help of whatever HVAC group that ensures more work/money for installers ~ planned obsolescence). It was that the blowers pushed higher velocity through smaller ducts and systems now push lower velocity (but more volume) through Bigger ducts. Use a modern fan with the older ducts and you put additional stress/strain on the fan which will lead to a shorter life and, I think, lower efficiency.


My installer said it was more important for the Return duct to be the right size than the feed, so that was the only one he replaced.
Thanks for the succinct explanation. I have someone coming to do a 2nd quote for me today. It isn't so much that I disagree with the ductwork assessment by the 1st guy, it is that he didn't give me the quotes I was looking for.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 09:04 AM
 
4,690 posts, read 10,344,851 times
Reputation: 14882
HVAC quotes are all over the map, at least mine were. I must have gotten 8~9 of them and the ranged from $4k~$12k. In all of my research the ONE thing that stood out as the most important was having a competent and capable installer. What brand equipment isn't #1, I don't even think is was #2 (though if not, I can't remember what was)... don't fret about the brand of equipment. Looked like most of the techs who self-installed used the brands that carry the "don't ever buy this brand!" label when you search online.



I ended up going with a company that offered certified (NATE?) techs, and they were one of only 3 who bothered to show up and Look at my house/system. No one even offered to run load calculations, though I was also shopping for a rental house I was getting ready to sell and not my main residence where I'd spend a little more to get a little more. Lucky for me they sold a name brand (I was selling, that stuff matters to some people) and at one of the cheapest quotes.


Good luck, I hated that process and I'm not looking forward to doing it again.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 09:13 AM
 
8,073 posts, read 9,993,317 times
Reputation: 22606
While you are changing your duct work from the 1990's, don't forget to put summer air in your tires.
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 11:40 AM
 
Location: TEXAS
3,784 posts, read 1,335,830 times
Reputation: 1997
Quote:
Originally Posted by dspguy View Post
I'm being told by an installer that gave me a quote that I need new ductwork..... we are talking about a split system (condenser outside, air handler in the attic, ducts in attic).

Is old ductwork flex-duct or galvanized? Old flex-duct tends to tear/crumble after 20-30 years....
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 12:14 PM
 
5,938 posts, read 4,671,889 times
Reputation: 4630
Quote:
Originally Posted by Ted Bear View Post
While you are changing your duct work from the 1990's, don't forget to put summer air in your tires.
Can I surmise that is your way of saying changing ductwork is bogus? Do you have any expertise in that opinion?
Reply With Quote Quick reply to this message
 
Old 06-21-2018, 12:15 PM
 
5,938 posts, read 4,671,889 times
Reputation: 4630
Quote:
Originally Posted by CCCyou View Post
Is old ductwork flex-duct or galvanized? Old flex-duct tends to tear/crumble after 20-30 years....
Flex. The house is 40 years old, but I can't say the ductwork is the same age. I think it was redone at some point in the last 20.
Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


Reply
Please update this thread with any new information or opinions. This open thread is still read by thousands of people, so we encourage all additional points of view.

Quick Reply
Message:


Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > House
Similar Threads

All times are GMT -6.

© 2005-2024, Advameg, Inc. · Please obey Forum Rules · Terms of Use and Privacy Policy · Bug Bounty

City-Data.com - Contact Us - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 - Top