Local HVAC inspector is now requiring at least R9 on flex duct in unconditioned spaces. All we can get around here at the local supply houses is the standard R4.2 stuff and the inspector won’t count the cellulose that will be blown in over the ducts when the attic is insulated. My HVAC sub thought since I use ‘that internet thing’ maybe I could find a source that he could pass on to his supplier. So any suggestions for a supplier, even an online source would be OK,
Thanks for any help!
Regards,
Dennis
Replies
is that a new code rule?
i thought r 6 was readily available- never heard of 9
It is the new code here. However it is so new that none of the HVAC supply houses here in town carry it. One place can get R8 but this still doesn't get us to R9.
"It is the new code here. However it is so new that none of the HVAC supply houses here in town carry it. One place can get R8 but this still doesn't get us to R9."
What code? I need specifics. If this some idiotic, one-off local yocal code, I can blow it off. But if this is based on a real, national mechanical or energy conservation code, I need to get some into my supply house, and all of the branches.
BTW, you can buy an insulated sleeve to slip over the insulated duct, doubles the R-4.2.
Timbo,
Not sure if it is a new national code or not and my HVAC guy didn't know either. Our local HVAC inspector does occasionally add stuff when he feels like it. We are currently following the UBC but the city will be switching to the IRC this summer. The IRC might be where he is getting it from. Also if you look at the Energy Star documents from the EPA, it says you should use R8 for flex duct (for cold climates) and some of the Super Good Cents programs I found on the web want R8-R11
Again, I have no problem putting in whatever he wants us to. We just need to find a supplier for what he is requiring. We should be having the HVAC rough inspection this week so I will ask him about it then.
Regards,
Dennis
Dennis,
I am very familiar with the Internation Code Council's documents, including the IMC 2003 and the referenced IECC (energy conservation code) but haven't heard of that one before. So, this may just be a case of the inspector making up the rules as he goes. Nothing like a clerk with authority.
"Nothing like a clerk with authority"LOL! -- It was long before building codes, but Rudyard Kipling felt the same way:THREE things make earth unquiet
And four she cannot brook
The godly Agur counted them
And put them in a book—
Those Four Tremendous Curses
With which mankind is cursed
But a Servant when He Reigneth
Old Agur entered first.An Handmaid that is Mistress
We need not call upon,
A Fool when he is full of Meat
Will fall asleep anon.
An Odious Woman Married
May bear a babe and mend,
But a Servant when He Reigneth
Is Confusion to the end.His feet are swift to tumult,
His hands are slow to toil,
His ears are deaf to reason,
His lips are loud in broil.
He knows no use for power
Except to show his might.
He gives no heed to judgment
Unless it prove him right.Because he served a master
Before his Kingship came,
And hid in all disaster
Behind his master’s name,
So, when his Folly opens
The unnecessary hells,
A Servant when He Reigneth
Throws the blame on some one else.His vows are lightly spoken,
His faith is hard to bind,
His trust is easy broken,
He fears his fellow-kind.
The nearest mob will move him
To break the pledge he gave—
Oh a Servant when He Reigneth
Is more than ever slave!
I have seen r-8 at supply houses
What abought wraping it twice?
You might be onto something. how about running the flex duct through another run of flex duct.Of course I have been told flex duct is trash for anything but short runs to registers. Inherently inefficient because of the rough inside surface and prone to degradation in time from simple environmental effects and physical damage.