[Rebel1]

Sambo, as you have read on this thread I have the alternate model with the vacuum trap door. I have done away with the vacuum motor and fitted a push pull arrangement.

Both of the vintage air units work the same way..... either defrost, in which case all air is directed to the screen or interior heat in which case air comes out of a trap door and from the defrosters.

I think the unit you refer actually prevents defrost air when you direct to the floor.

In either case, they are bluddy good units. Way too much air to the defrosters. So much that I considered redirecting one of the defroster outlets to somewhere else and put some sort of butterfly valve in that hose.

I got the unit I did because it is just a little more compact that the one you refer.

Cheers