Air sealing all the ducts and air handler connections and seams and air sealing all the duct boots to the ceiling gypsum and any other penetrations is a critical first step prior to adding any insulation.
Attic duct boot pictures.
I was thinking of using great stuff and sealing around the boot.
Wooden house with metal roof attic air duct balcony rain gutter.
Jump ducts which do not directly deliver conditioned air from the hvac unit may be located in attics if all joints including boot to drywall are fully air sealed with mastic or foam and the jump duct is fully buried under the attic insulation.
This way there is no infiltration at this point.
When you put a duct and a duct boot in the cavity you don t have room for insulation.
I made a foam mock up of the inside of the duct starting with a base and 19 round.
They helped us replace air ducts and boots on the attic install a new furnace flue pipe bubble wrap the furnace plenum box seal all joints well.
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.
Because my roof was a 3 12 pitch the attic space is real cramped and the supply ducting filled it up leaving little room for the return ducting.
Btw they offer 5 year warranty on their work.
If the walls are framed with 2x4s there s often not enough space even for a little bit of duct insulation.
The foam does have an advantage in that while the boots are being foamed one can also seal the joint between the boot and where the boot is mounted ceiling wall floor.
They are usually the same size as the loop duct.
Also they are detail oriented the clean up and rodent proofing work were completed with care.
Only older heating only systems have uninsulated boots.
Ventilation specialist assembling air duct pipe system in attic of new construction of residential building male contractor binding ventilation pipes with duct tape.
The point about testing expansion is a good point to consider.
As most of the duct installs here are in the attic with insulated boots it then becomes the hole where the boot pentrates the ceiling that becomes the dewpoint concern.
Even if the duct and boot have some insulation these components are rarely sealed.
The best solution was to make a custom return duct boot filter holder.
I will use a combination of doors and windows great stuff and the normal expanding great stuff.
Either duct wrap the boots or foam them.
Most supply boots here in my area are insulated.
The following pictures show the process.
Oversized cuts for boots that are not mastic sealed.
They did a good job and the charge was reasonable.
The boot boxes are sized to deliver the proper cfm to each room of the structure.
Pictures of the roof vents turbine vents and attic from both the interior and.
Duct losses to outdoors.
Supply duct system locations decisions regarding the location of a supply air dis tribution system should be made based on the.
