airflow

[stevemc]

What do you do when you cannot get proper airflow for AC installations. In my location we have tight building construction with low cooling loads. If you notice furnace manufactures fan curves don't work well with 1 1/2 ton or 2 ton systems. Most of furnaces start around 900 cfm on low.
What do you guys do with a siyuation like this? Or a belt drive system that is set for the proper air flow for heating?

[dan sw fl]

Originally posted by stevemc
If you notice furnace manufactures fan curves don't work well with 1 1/2 ton or 2 ton systems. Most of furnaces start around 900 cfm on low.


What's the dP @ 700 CFM on the fan curve?

Use dampers and high efficiency filters to achieve lower ( slightly < 900) flow with furnace set on Low.

[dash]

Increase the ESP,with better filters,and/or a damper(s),in the main supply and return.


The higher ESP,should be able to get the airflow down to what you need,check your fan chart.