How large of a building will it heat and cool?

Thank you for your question. A 12,000 BTU system will generally heat a single zone or space/room that is between 400 to 650 sq. ft. However, this is dependent upon a few different factors such as quality of insulation, number of windows and climate zone. For instance, a system installed in a home in North Dakota with poor insulation and 12 windows would efficiently heat less square footage than the same system installed in Kentucky with quality insulation and 5 windows. If you are looking to heat multiple zones or rooms, we would recommend a multi zone mini split system. For more assistance, please give us a call.