I want to replace some battered, ugly radiator covers in my 1910 home. I have read that to function effectively, a radiator cover needs openings at the front top and bottom, so that natural convection will pull cool air in from the floor, then at the top of the cover, hot air will flow outward toward the center of the room, rather than straight up as in the case of an uncovered radiator.
Here are my questions:
Is this true?
If so, how large should the openings be at the top and bottom of the radiator cover?
How much clearance should I allow above the top of the radiator? (This clearance may be limited because I don't want to block windows.)
Should the inside top of the radiator cover have a square corner at the back, or is there some other configuration that will promote better airflow?
Are there any relevant reference works worth consulting?