By Charles Wardell

Mitsubishi Electric HVAC, has introduced the first residential split system heat pump to power three indoor zones from a single outdoor unit. It includes a compressor technology that the company says has, until now, been limited to commercial units: a variable-speed compressor that ramps up or slows down according to what the indoor unit is calling for. That means lower energy use and faster response to temperature swings. A 30,000 BTU model with three zones will list for approximately $5,700. For more information go to