What size blower?

[Father & Son]

This is a previous post under "Blower" that i have posted numerous times -

CFM's are calculated on stack size not evaporator size


From a previous post -


(The blower size is based on stack size.

The formula to figure stack area is pi x radius squared, pi = 3.1416, so the area of my 7" stack worked out like this

3.1416 x 3.5 x 3.5 = 38.48 square inches

38.48 square inches x 3 cfm/square inch = 115.44 cfm's

Correct me if my math is wrong but this gives you a way to figure what size blower you need.
I bought a 265 cfm blower just to give me some flexability for later improvements.)

With a blower that is oversized you can either put it on a rheostat or put a damper in the duct work to adjust your flow.

I now use this blower on a 2x8 with a 10" stack and still have to damper it down.

This formula was posted on here a few years back by someone with more knowledge than me but I have refered to it many times.

Jim

[WESTVIRGINIAMAPLER]

I have a 2x8 Leader and have been running a 745 cfm blower on it. The 2.5 x 8 from Leader come with a 960 cfm blower on it.

Plenty of good Dayton blowers cheap on ebay if you take your time and watch for a few weeks, you can get a steal deal.