Homeowners can reduce their annual water use by thousands of gallons annually by adding a simple, low-cost hot water recirculation (HWR) system like Grundfos Pumps' Comfort System that saves water by delivering hot water on demand. In homes larger than 2,000 square feet, the Comfort System can save more than 16,000 gallons of water per year and deliver the convenience of instant hot water. The system can be installed easily in existing homes. Grundfos Pumps Corp. Circle 2.