Q: A customer asked me to build shelving units around the walls of an over-the-garage family room. There's 8-inch-tall hydronic convective baseboard on every wall, so she asked me to just build the shelves down to the floor and put louvered registers in the bases along the bottom. I explained to her why this wouldn\'92t work so well. So my question is: how far above the top of the convectors should I put the bottoms of the wall units (they\'92ll be 8 to 12 inches deep) in order to allow enough laminar airflow throguh them and out into the room  i.e., so that the 

  • Credit: Ima Moron

A. Hydronic expert John Siegenthaler, owner of Appropriate Designs in Holland Patent, N.Y., responds: 
I don't have any research or test results to back this up, but would suggest keeping the lower shelf at least a foot above the top of the baseboard. You might be able to construct a sloping skirt board that would start above the baseboard perhaps a couple of inches out from the wall, and then slope up and out to meet the outer edge of the lower shelf. This would help guide the rising convective plume out into the room. Also be aware that any wood used for the lower shelving and skirt will become extremely dry during winter due to the wash of warm air. Be sure the wood is kiln dried, or use plywood. Also remember that the fin-tube should be periodically vacuumed to keep it performing well.