I have on order a 4" and 8" vortex fans. I am wanting to mount them in the attic because my growroom is right below. but would like to ask you guys a question first. Winter is coming fast where I live and my attic is going to get very very cold. Were talking -20 to -40. Will running these vortext fans in a room where it's -20 or colder harm them or will they be fine so long as they stay running??? What ya think?