We've removed an old wore out dysfunctional shutter system on our bus prior to our 1st AK road trip.
We finally substituted the shutters with an effective DIY winter front made from a HD nylon foam insulated SCUBA backpack.
We about got it pre-fit & are about to install the SS marine snaps for easy installation in deep cold driving conditions. I don't think centering the available air in will be an issue with fan balance as the total distance from the fan blade leading edge to the winter front is 13" Got a feeling we're gluten for cold AK winter(s) in our future... :#