Shuttered Exhaust Fan

maninthesea

Hello
I am looking to get a couple of shuttered exhaust fans to remove hot air from equipment rooms housing High Pressure Air compressors. These machines are air cooled and produce a LOT of heat.
One fan is replacement for a 36" direct drive fan that I installed almost 10 years ago to keep a 30HP compressor supplied with fresh cooling air. At that time we ordered the fan from Grainger and was $500 now same fan is over $700. I want to know if you guys know where I may be able to shop online for
1 30 or 36" shuttered fan for the 30HP compressor. I would prefer around 7000cft per min would accept 5000cft per min
1ea 24 or 30" fan for 20HP compressor for this one I would like 5000cfm or more but would settle for 4000cfm
I really would rather stay away from Grainger due to issues in the past plus high prices.

PS my rule of thumb when installing these is to double the inlet opening compared to the fan size. Exh fan is mounted as High as possible on the exh side of the compressor and if possible the inlet opening is low as possible preferably on the cooling air suction side of the compressor.

Thanks in advance for the links to good suppliers.
Cheers Jim