roamet
New Member
My HVAC sub on a new build condo project ran 8 round inch trunklines for a 1.5 ton unit. The space needs about 720 CFMs which also makes me wonder if 1.5 tons is enough. When I brought this to his attention, he claims:
* yes, 8 inch is on the high side but will work.
I told him I can't imagine how this will not produce noise, strain on system and increased utility costs and that I want the trunklines changes to 12 inch.
He now claims if he splits the main trunkline into two - essentially running a T off the plenum, this will address any issues and make the 8 inch work.
Questions:
* Is this logic correct
* Even if it is correct, a 1.5 ton is essentially providing 600 CFMs which means each trunk would carry 300 and would need a 10 inch duct? (the trunklines will be split at mid point of each condo so they will servicing pretty much the same CFM needs)
* Is 1.5 ton sufficient for my calculations of 720 CFM needed.
* yes, 8 inch is on the high side but will work.
I told him I can't imagine how this will not produce noise, strain on system and increased utility costs and that I want the trunklines changes to 12 inch.
He now claims if he splits the main trunkline into two - essentially running a T off the plenum, this will address any issues and make the 8 inch work.
Questions:
* Is this logic correct
* Even if it is correct, a 1.5 ton is essentially providing 600 CFMs which means each trunk would carry 300 and would need a 10 inch duct? (the trunklines will be split at mid point of each condo so they will servicing pretty much the same CFM needs)
* Is 1.5 ton sufficient for my calculations of 720 CFM needed.