When is post-construction duct sealing worth it?
I have a ca 2000 home built a tad better than code at the time, with a 2-zone HVAC, and a ductopus in the attic. Zone 4.5.
I’ve been thinking about getting the ducts tested, and based on the results, having them sealed with the Aeroseal system. For those not familiar with it, the operator essentially pressurizes the duct and sprays a kind of liquid caulk into the duct. The process continues until the level of sealing desired is accomplished. There’s an article here on GBA on the process as used to seal up entire houses, and I understand the whole-house sealing is a development based on the prior use of the technology in sealing ducts.
Prices I’ve been getting for duct sealing, including the returns, are in the $3900 to $5000 range, which seems like a lot- hence the question, which is: does it make sense to spend that much on sealing ducts in a ~3800 sq ft home? What are the anticipated savings, and how would I calculate that? Even anecdotal reports would be helpful.
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Replies
Without test results, it would be nothing but a guess. Even with them, more data/guesses are needed - hours/year of operation, temperature, pressure, etc.
It is sad that someone made the bad decision to put ductwork in the attic.
It is possible the person that made that decision understood it would be important that the ducts do not leak and spent the time that is so rarely taken to do a first class install that does not leak.
Without testing everyone is guessing how much they leak. Some installs are obviously done poorly and with ducts falling off or crushed.
If you want to know you must pay to have them tested, you will need to find someone with a blower door and a duct blaster to do the testing.
If you are willing to get dirty it is not complicated to redo the ends.
Walta
Yeah, I can get it tested- and that is part of the Aeroseal process anyway- but the question is really whether it's worth it or not in terms of reduced utility costs, etc.
You'll know how much more the ducts are sealed when it's done, but you won't know how much you've really saved until you've made the choice to actually do it.
And that's the crux of the question. I was hoping perhaps someone else had done it and gotten A-B utility bills to try to ferret out the impact, or perhaps a study that had addressed the issue.
Whether it "pays off" depends on your energy costs, the actual leakage rates, and whether it's a conditioned attic.
There is a lot of duct and duct-boot sealing that can happen for under $50 as a DIY with buckets of duct mastic and rolls of purpose made aluminum tape. Fix all of the obvious stuff even before getting the ducts tested.
How much do contractors charge for duct-blaster testing in your area?
Hi Will -
While that cost does seem high for the annual energy savings you could expect, the other thing to consider are other benefits: increased thermal comfort AND reduced chances of duct leakage-driven pressure imbalance in your home, with IAQ implications.
Peter