The Tranquility 22 Digital Series is an economical alternative for significant energy savings AND unmatched home comfort.The Tranquility 22 Digital is a game-changing new geothermal heat pump that is the first in the industry to integrate digital communicating controls, 'Plug & Play' integrated variable-speed water flow, two-stage capacity, and variable-speed fan. The system is engineered for quiet, efficient operation and comes in multiple capacities. The eco-friendly Tranquility 22 Digital already meets ENERGY STAR Tier 3 efficiency levels, so it will qualify for the uncapped 30% federal geothermal heat pump tax credit in 2012 and beyond.