Further improve performance by applying a heat pump system with a compact duct design instead of a large, complicated, conventional duct design. During heating season, thermal energy is lost as conventional systems push conditioned air through long duct runs in unconditioned spaces. This heat loss through ducts can result in comfort issues not to mention poor energy performance. Similarly, in cooling season, long duct runs can result in hot air pushed from hot ducts.
In compact designs, heat pump duct runs are shorter and more centralized with ducts running to interior walls and blowing toward exterior walls. With shorter duct runs, and less opportunity for energy loss, builders can install smaller indoor units with quieter fans. Ductless indoor units for heat pump systems, such as recessed ceiling cassettes or wall-mounts, don’t require ducts. Ducted air handlers, which might replace an old gas furnace in a retrofit, and horizontal-ducted units, which are about the size of a suitcase, are compact so builders can more easily fit all HVAC equipment and ductwork within the envelope.