The Variable-Speed Water–to–Water (WV) system provides in-floor radiant heating, forced air heating and cooling, and 100% of the home’s domestic hot water in one compact, efficient package. This unit is much more efficient than a traditional HVAC unit, which could save you 50% or more on climate control energy costs. Like the Variable-Speed Air-to-Water Advantage system and Air Handlers, the WV is available under the Enertech brand.