# location of duct booster



## mga56rg (Jun 29, 2017)

There is poor register CFM in my clients second floor bedroom and hence I need to install a duct booster and have chosen the Tjernlund M6 (Centrifugal style). It will be installed in the basement crawlspace (the closest I can get it to the register, maybe 2/3rds of the way down the total run). There is a Y in the duct around the area I will be installing the fan. 

My question is whether the booster fan should go before or after the Y? If i put it after the Y, I've heard these fans are strong enough to pull airflow backwards from the other nearby registers. If i put it before the Y, maybe half the CFM boost would go to the wrong register. Was thinking before the Y, then putting in a damper to redirect to the proper route. 

Thoughts?


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