Choosing the best heat pump for a freezing room is not easy. The Northeast Energy Efficiency Partnerships (NEEP) heat pump directory contains over 30,000 different models, each with a huge number of features. Hyper-Heating (h2i), manufactured by Mitsubishi, is the best heat pump for cold environments. Not only can these heat pumps generate usable heat down to -13 degrees Fahrenheit, they also maintain full heating output down to 5 degrees Fahrenheit. Heating seasonal performance factors (HSPF) for h2i models range from 10.5 to 12, while seasonal energy efficiency ratios (SEER) for cooling range from 15 to 20. Coefficients of performance (COP) of up to 2.88 are maintained by their heat pumps at temperatures as low as 5 degrees Fahrenheit.