A: Mini-splits and variable-refrigerant-flow multi-splits. It's not that mini-splits and their multi-split kin aren't available in the U.S. at all. Daikin, Mitsubishi, and Sanyo all sell products here, along with a few other manufacturers. It's that this cooling technology (which uses an air-source heat pump and can provide significant heating capacity along with cooling) is in millions of homes and businesses in Asia, Australia and New Zealand, and Europe, and is comparatively absent here despite numerous benefits. (The photo is from T'bilisi, in the Republic of Georgia. It shows an exterior unit that provides cooling to an indoor air handler at a hotel. Condensate is piped down to a potted plant -- a nice touch.) Sensing that the technology was getting short shrift, I investigated it in a feature article in the latest Environmental Building News. Here's what I found:

• Efficiency numbers potentially matching those of ground-source heat pumps, even for heating in a Northeastern climate!
• Efficiency is really boosted where simultaneous heating and cooling is needed in the same building (not that uncommon in larger buildings
• Not the cheapest products, but costs comparative with other cooling systems
• Appropriate for homes, small commercial, and up to medium-sized buildings
• Variable speed-compressors and air-handling units function very efficiently at partial loads
• And, more benefits and drawbacks, summarized here.

The technology is all over the place in the rest of the world. It was a common sight for me in the Repubic of Georgia, a rebuilding post-Soviet republic. Here's the inside air-handling portion of the exterior unit shown in the photo above: Typical street scene in Georgia with an older cooling unit on the left and a newer mini-split on the right: Jeff Pratt, an energy efficiency consultant to the Northwest Energy Efficiency Alliance (Portland, OR) working on market transformation initiatives, was kind enough to send me a few images for the EBN article. Here's a nice house in Sweden with a unit: One representative I spoke with at an unnamed American manufacturer (one that doesn't have much of a presence in this product line) seemed to suggest that mini-splits are somehow... not American. Americans like open floorplans, big homes, cooling that they don't have to think about rather than adjustable units in each room, he said. He talked about the Asian market as though mini-splits owned it because of the small rooms there. Read the full EBN article here.