Reversible Vent Fan

Technical discussion aside, don’t buy and install a vent fan that doesn’t pull air in and exhaust air out as you choose.

My Maxx Air only expels air, as it's uni-directional. I wish it had a reversible motor, as it is sometimes useful to be able to draw cooler or warmer air from outside, in.

Mine s reversable, and I have used it both ways, depending on the occasion and need. However, I haven't checked ours too closely, but most fan blades are designed with a curve like an airplane wing, to move air better in one direction. Doesn't mean that it won't work the other way, but there may be a slight difference. Probably not enough to notice. Observe most home ceiling fans, those blades are just flat paddles, and they will move air in either direction.

our FF moves air in both directions. we rarely have it pull air in.

Last 3 RV's have had a reversible Fantastic Fan. Seldom used the intake mode. We do have the thermostatic control which is useful.

FF's are good in both directions until the chinese motor expires.

We've got a FF over our bed and every once in a while we use it to bring in some fresh air for awhile. All DC motors are reversible. All you need to do is swap the positive and negative wires to the motor. It takes a double-pole/double throw switch to do that. If you buy one with a center off position, it will just like the one FF uses. Not hard to add at any time. The basic FF motor, fan and housing are all alike. The accessory options are added to enhance it's operation - like reversing directions, rain sensor, motorized opening/closing, temperature control and multi-speed switch. There's even an option for remote control that gives 14 different speeds. All of these can be added to the basic unit without changing the motor blades or housing. One of the nicest add-ons is the pop-out screen so you can wash the lint build and bugs off easily.

"If you buy one with a center off position, it will just like the one FF uses"
Presumably then you could also add your own speed controller as well.
https://www.ebay.ca/itm/DC-12-40V-10A-PWM-Motor-Speed-Control-Switch-Controller-Volt-Regulator-QP/254347852877?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D20160908110712%26meid%3Df908c075ed794b128a4f7a9dfee6c9ca%26pid%3D100677%26rk%3D4%26rkt%3D30%26sd%3D323886635244%26itm%3D254347852877%26pmt%3D1%26noa%3D0%26pg%3D2385738&_trksid=p2385738.c100677.m4598

Or this one to do both reversing and speed control.

Regards
Fred

Mine is reversible however for me pushes air out only. No reason to pay extra for this option IMO.