Vortex 6" fan temperature limits a problem? Ventilation.

[HausBrauerei_Harvey]

In a previous thread I detailed a bit on the brew room i'm building out. I'm building a natural gas powered brew room, connected to my house with a shared wall but not otherwise.

I cut in my two exterior vents this weekend, I'm doing a small 4" fan over the HLT, and a big 6" fan over my dual boil kettles. The burners are both 100K BTU wok burners, I will usually be using just one burner at a time, occasionally I will do dual boils and split batches and run both burners at once.

Anyways I was all set to buy the 6" vortex can fan on amazon just now which is very popular in use for the electric brew DIY vent hoods. Although the specs on the fan say don't use above 140F or the propellers will melt! Someone also stated in the comments they tried to use the fan with a oven vent and the blade melted. Do folks think this will be an issue? I suppose I could fire up my kettle and take some measurements of temperature above the kettle but I figure others have done this already.

For the record the hood will be a steel barrel (will suck some heat) and it will be about 3-4 feet above the top of the kettles, the fan will be only about a foot from the hood, very short run before going outside. I'm using steel double-wall ducting, FWIW.

Thanks for the input, I tend to overthink things sometimes so it will be good to have some others chime in.

For those that like pictures I've included a few photos of the inside and outside of the vents. At some point soon I should put together a thread of my brew room build.

 

[day_trippr]

140°F could be close. I run a big split squirrel cage blower and had to provide separate cooling air ducting to the motor housing because it would execute a thermal cut-off when I was pre-boiling my brew day liquor with both the BK and HLT burners cranked up. iirc that cut-off switch was set for 140°F, and the motor wasn't even in the actual ducted flow (that's the other side of the split blower) but was in the heat wash trapped in a vaulted ceiling above the rig (a well designed hood would solve this long term. I'll get to it eventually).

Aaanyway...one thing that strikes me is that exterior hood: it looks highly restrictive. You might consider going with an "automatic" vaned version that pretty well exposes the entire duct to the outside in a straight shot with very little restriction...

Cheers!