> Be that as it may, heat pumps at this time are cost prohibitive. They range from sub-$1K single zone air-to-air wall/window units, to multizone split units,

> Be that as it may, heat pumps at this time are cost prohibitive. They range from sub-$1K single zone air-to-air wall/window units, to multizone split units, to ground source hydronic boiler/chillers that integrate with baseboard or radiant floors, which can get quite expensive to install, but that's at the high end. Generally speaking they're not really much more expensive than normal air conditioning. I've seen units that come in cooling-only and heating+cooling versions, and the cost difference is marginal (<10%) in those cases.