The Ultra Force™ commercial gas-fired series of water heaters are rated at 94% thermal efficiency and are designed to deliver higher output with lower input than conventional units, according to the manufacturer. The unit is available in three models: SUF100, 150 NE, SUF100 199NE, and SUF100 250NE with 150,000 Btu, 199,000 Btu, and 240,000 Btu inputs respectively.