Is there a "rule of thumb" for choosing a subwoofer based upon the volume of air in the listening area?

I'm trying to find a sub (most Likely Hsu) and I just was wondering if something like this exists. My room is about 14' x 20' x 8' (2240 cubic feet).

Any suggestions?

VP100, M60ti's, HSU STF-2, Marantz SR7200, 55" Mitsubishi