Government funding and grants play a key role in the growth of air-to-water heat pumps in the areas like Maine. If the homeowners install air source heat pumps in Maine under the Efficiency Maine Home Energy saving program, they are eligible for $500 plus $250 for a second zone up to $750. If you want to take advantage of cold weather heat pumps in Maine, please check out the analysis of heat pumps popularity at https://www.arcticheatpumps.com/.