Withair® Variable Speed Water Source Heat Pumps Imagine a product that delivers superior comfort and performance while reducing operating cost. Every building should have an HVAC system that delivers maximum comfort and efficiency without compromise. Which is why Withair® maintains a lineup of water-source heat pump systems with a wide variety of configurations and designs to ensure compatibility and performance. Vertical, horizontal, rooftop and console installations are supported, as well as buildings with either three-phase or single-phase electrical service. Regardless of the configuration, every Withair® system is built to provide dependable performance day after day, year after year.