Thanks. Kitchen isn't too big so there's not a lot of places to put the thing. I'm going to readdress the issue with GC. The builders seemed to pick the worst places to put the vents. This one is in front of the garage door. The one in the den is in front of the sliding glass door--I have to have my rug shifted over so it doesn't cover the thing and so we have to step in sideways to step on the rug rather than the vent when we enter--that one is getting moved to the right to get out of the door entry.

I agree with Ingrid—a nice sisal would work, except I’d skip the contrasting binding. And to answer your question about whether or not anyone’s done this, my brother & his partner have—more out of necessity than anything else (kind of like you, I guess!) They live in a pre-war co-op building in NYC with terrific, original-but-noisy-for-the-neighbor-below-you hardwoods, and each apartment is required to have a minimum percentage of the flooring covered so they did exactly what you’re considering in both their living and dining rooms. And it looks great!

If your duct is 6 inches or less (OTR microwave vent or minimal hood vent), then the restriction might be expected to be commensurate with whatever duct cap might have been used in place of it. However, through wall venting usually doesn't provide the distance needed for a round to rectangular adapter, so this type of vent would most likely be suitable only for low flow hoods that can adapt to rectangular ducting. The commentary at the link using the term "most hoods" might be a stretch, or maybe an indication of an appalling world-wide lack of adequate kitchen ventilation. Starting with what is to be ventilated leads to hood size and volumetric flow rate requirements. From the flow rate the duct size can be determined. Without all of the cooktop ventilation parameters, effect of this vs. some other interface with the outside world cannot be adequately estimated. Further, it is also possible that the blower used in a given application can be deliberately oversized to tolerate the small sectional area of the device (at a cost in noise).

Rehabit, could you please let me know the maker of the vent cover and where I can find it? Thanks