Does my AC unit double up as a heater in the winter? Jessica 29 June 2021 00:48 Most portable air conditioning units do not double up as a heater, but we do sell a 12,000 BTU 4-in-1 Portable Air Conditioner & Heater which can be used all year round. Related articles Can I use a portable air conditioner in a room without a window? Will my AC unit cool my whole house? How often do I need to drain the watertank? What size is the window kit? What size Air Conditioner shall I get?