What windows is the All-Weather 120V heat pump compatible with? December 03, 2024 16:31 Updated The All-Weather 120V heat pump is only compatible with single and double hung windows (windows that open vertically). Related articles What refrigerant does the All-Weather 120V heat pump use? What is the CEER and HEER of the All-Weather 120V heat pump? What are the dimensions? How many people are required to install the All-Weather 120V heat pump? How do I install my Gradient All-Weather 120V Window Heat Pump?