I would like to add a kitchen exhaust but do not want a hood or downdraft.  I simply want something similar to what was used in the 50s and 60s. However I am not seeing any on the market, with the exception of actual vintage Ventrola models. Is it possible to use a through wall fan and just have a custom cover made? Is there a reason to not do that? I have a typ 4 burner range and have a hard time thinking there will be that much grease build up.