The N-Vintage water-source heat pump line is designed to meet the new minimum-efficiency requirements that go into effect October 2003, under ASHRAE Standard 90.1, the company says. The pumps are medium-efficiency, horizontal and vertical units that range from 1/2 to 6 tons. According to the manufacturer, the pumps’ footprints accommodate space constraints, while an HP3 microprocessor controller ensures reliable operation. All units are certified per ARI/ISO 13256-1 and are ETL-listed, the company states.