Is it worth it to Seal my Attic HVAC Boots
I've searched the forum and it looks like I do not have insulated boots and when i went up to the attic today, i noticed the boot was cold to the touch and had a small draft coming from where the boot meets the Sheetrock of the ceiling.
I was thinking of using great stuff and sealing around the boot. I will use a combination of doors and windows great stuff and the normal expanding great stuff.
I also noticed a small hole in the diffuser box (I think that is what it is) and I will use great stuff to seal that. There is also a small amount of mold on some of the tape.
Bottom line, is it worth the cost for 20+ boots to seal with great stuff. I have blown fiberglass insulation and I live in Southern Alabama and will probably only live in this house for another 2-4 years
Any air leaks are worth sealing and any duct work in a unconditioned space its best to insulate as you are paying to condition the air as for usin great stuff be careful it can go every where might try caulking first
20 leaking boots can be a lot of air leakage. Sealing them can greatly increase your comfort, and reduce your cooling bill, along with your heating bill.
Originally Posted by Nate5452
I just sealed mine from the inside with the silver tape. I think it helped with condensation I was having since warm air was coming in and hitting the cold register.
Ditto what these guys say.
Yeah, duct mastic, 1" spackle trowel & a paint brush first.
Originally Posted by catmanacman
Which makes more sense to you?
- turning your thermostat back and being uncomfortable. Maybe saving 5-10%
- leaving your thermostat where everyone is comfortable. Saving 30-70%
DO THE NUMBERS! Step on a HOMESCALE.
What is comfort? Well, it AIN'T just TEMPERATURE!
Energy Obese? An audit is the next step - go to BPI.org
, or RESNET
, and find an auditor near you.
I sealed my in ceiling vents buy removing the vent and calking. Although I didn't think that they all looked that bad my humidity dropped 6 for 7 percent. I also sealed all of the recepticles and switches. In the summer I see mostly 51% dropping to 49 or 50 at times. Being in southwest Florida near a lot of water that isn't bad at all.
I would use water based mastic to seal all gaps and seams on the boots, including any gap between drywall and boot. Be sure the register grill is off and remains off until the mastic has thoroughly dried. Same would apply if you chose caulk or foam over mastic.
After sealing all seams with mastic, buy some shiny mylar coated duct wrap and then wrap the attic side of each boot. Tape all seams created by the wrap with foil tape. Mastic the tape. I'd do that vs. spraying "Great Stuff" foam everywhere. The foam will give you some insulation but the mylar coating on duct wrap is a radiant barrier, which you need with ducts in an attic.
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.