They work somewhat like a fridge-freezer, but in reverse. The intelligent know-how employs electric power to get heat in the air outside – even when temperatures get as little as -15C! Cost is depending on a full estimate from A different MCS-accredited heat pump installer for just a like-for-like installation. https://propane-heat-pumps47899.shotblogs.com/the-best-side-of-industrial-waste-heat-recovery-43382476