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BowhunterNC
03-24-2009, 08:12 PM
They had an Energy Star/ Blower test on a set of town homes we installed the HVAC on and came back with a 2% duct lost. They said that 6% was Energy Star certified so I'm pretty pumped!!
jimj
03-24-2009, 08:20 PM
They had an Energy Star/ Blower test on a set of town homes we installed the HVAC on and came back with a 2% duct lost. They said that 6% was Energy Star certified so I'm pretty pumped!!


Good job, thats a very tite duct system.
HVAC/Stud
03-24-2009, 08:50 PM
What was your ESP? You can have tight ducts and high ESP that prevents correct airflow. If could have more ESP than your blower can handle.

STUD
BowhunterNC
03-24-2009, 09:16 PM
We have not started the systems yet, later this week. Are you saying it my be do tight?
Shophound
03-24-2009, 10:48 PM
We have not started the systems yet, later this week. Are you saying it my be do tight?

Only if you did not size the ducts correctly, or in the case of flex, they are not stretched tightly...whether they be sized correctly or not.

ALWAYS good to check your ESP when firing up a new install. You are taking justifiable delight in installing a tight duct system. Carry that one step further and confirm your duct design by good performance testing.
BowhunterNC
03-24-2009, 10:56 PM
I did a Manual J and Wrightsoft design room by room cfm calculation, I feel pretty good about it. Also it has a zone dampers with a static bypass;)

Thanks for the advise
energy_rater_La
03-25-2009, 10:01 PM
that is impressive. Energy Star says no more than 5% duct loss.
hard to get itrw..but its all in the details.
bet y'all use a LOT of mastic!!
Congrats!
amickracing
03-26-2009, 01:39 AM
I've worked on many commercial systems that were high pressure and required less than a 3% leakage, and that seemed almost impossible to get.

I'd say you done good!
BowhunterNC
03-26-2009, 06:04 PM
Man we used a ton of mastic, we did all our seams twice on the metal boxes and collars. Also we let them bake in the sun. They say most lost is at the take offs at the plenums. We would hit the inside of the flex with mastic, hook it to the collar, zip tie it, put venture tape on the liner and collar, mastic again the slide liner up, zip tie again. Took longer to install, but was moving toward the end.

Thanks for the replies.

BowhunterNC