In the process of having my crawlspace sealed and need to replace the metal ductwork.
all duct in crawlspace
5 ton A/C Gas Pack (not looking to replace at this time)
90’ feed
19 registers
1 return at 75 ft
1 return at 30 ft
Boots and register are in good shape.
Crawlspace is 30” high on average.
Crawlspace is fully illuminated so it’s easy to work in.
Currently it’s is a mix of flex, hard round, and hard rectangle ducting. Most is original 1966. But has been hacked and diverted over the years as the systems changed.
New work
All metal ducting. Flex can be used near the boots for sound deadening.
Prefer low wide trunks. 12x24 or similar to allow free air movement in the crawlspace.
Fully sealed and insulated.
If you know a company or crew who specializes in this please let me know.
wstrickland on this site is the guy to get in touch with. He will be along shortly I presume. I just sent him a message to come here.
After being released, a lot of fish die, but a lot of them live also.
quote:
Originally posted by CaptFritz
wstrickland on this site is the guy to get in touch with. He will be along shortly I presume. I just sent him a message to come here.
After being released, a lot of fish die, but a lot of them live also.
Feel free to call me at 843-202-1217
Thanks
That’s why I love this forum.
Thank you Captain Fritz.
Find an HVAC guy that can and is willing to run a Manual D calculation. That’s the industry standard to determine duct design and register sizes.
To do that they must run a Manual J calculation or at least simulate one.
Or you can go with a seat-of-the-pants cheap install and you might get lucky, and get something that kinda works.
A good design and install will improve comfort, eliminate drafts and result in the lowest possible bill.
You said you weren’t replacing the unit. That may be a big mistake. The duct system should be designed to manage and deliver the air flow produced by the unit. The larger the unit the more air flow. If your unit is too large and your brand new duct system is based on that unit that’s a problem.
Have them do the J. That will tell you about unit size. Then decide if it will be replaced. Most HVAC people are just pushing tonnage with no regard to comfort and cost control. The larger the unit the higher the utility bill. If your house actually needs 5 tons then it’s big enough that you would be much better off with 2 units.
A decision about a new unit is about a 12-year decision. A decision about a duct system is forever.
If you’ve done any energy improvements with attic insulation, windows doors, or ventilation I doubt you need 5 tons. The old school 500 feet per ton is ridiculous. I bet at one time the unit was smaller and when it was replaced the guy convinced you to go up a ton, “it will work better and you’ll never get hot.”
Pioneer 197SF
Bluesky
Do you know an HVAC guy that can do that for me?
That’s why I’m here and asking for a specialist.
We use Trent Goodman PE, he can do both and stamp it for you. Usually around $500 a job. But if you really wanna get it right, this is the best way.
quote:
Originally posted by friogatto
Bluesky
Do you know an HVAC guy that can do that for me?
That’s why I’m here and asking for a specialist.
Sorry, I don’t. Used to live in Charleston but have lost track of the dealers. One that I still keep in touch with is P&H Mechanical in Summerville. I don’t know if he does this but he is a good guy.
Pioneer 197SF