HVAC Site - Professional HVAC Contractors Forum banner

Return air vent size for 2150 cfm

574 Views 3 Replies 4 Participants Last post by  markusolas
I have a 5 ton Trane split system that puts out 2150 cfm and it does not seem to heat the house and runs constantly, air temperature at all the supply vents is around 100 degrees. I'm concerned that the return air boxes are not sized correctly. There are 2 ceiling mounted flex duct returns 1 is 18" and the other is 12". The return air box is 12" wide by 28" long for the 18" duct and 12" x 23" for the 12". Return air for the 18" duct whistle and air movement can be felt directly underneath it. The 12" return air makes little noise and no breeze is felt. Both have grills that are pretty restrictive however with a clean air filter and open grills little changes. What am I missing? Thanks so much. Scott
1 - 4 of 4 Posts
I have a 5 ton Trane split system that puts out 2150 cfm and it does not seem to heat the house and runs constantly, air temperature at all the supply vents is around 100 degrees. I'm concerned that the return air boxes are not sized correctly. There are 2 ceiling mounted flex duct returns 1 is 18" and the other is 12". The return air box is 12" wide by 28" long for the 18" duct and 12" x 23" for the 12". Return air for the 18" duct whistle and air movement can be felt directly underneath it. The 12" return air makes little noise and no breeze is felt. Both have grills that are pretty restrictive however with a clean air filter and open grills little changes. What am I missing? Thanks so much. Scott
How many square ft. Is residence? But yes duct work to small I would want two 20 in runs of flex. Your grills should be two 24 x 48 grills or equivalent area ex: four 12x24 grills.
Makki HVAC is the best HVAC service provider in Toronto. They provide a wide range of services, from air-conditioner repair and installation to hot water heater repair and installation. Their technicians are highly trained and experienced in providing top-notch services to their clients

https://www.makkihvac.ca/
You need to measure static pressure at the furnace. You looking at 0.5” wc. Post pictures of your furnace set up and filter box
1 - 4 of 4 Posts
Top