Section 15A-6-102 - Nitrogen Oxide emission limits for natural gas-fired water heaters(1) As used in this section: (a) "BTU" means British Thermal Unit.(b)(i) "Heat input" means the heat of combustion released by fuel burned in a water heater based on the heating value of the fuel.(ii) "Heat input" does not include the enthalpy of a water heater's incoming combustion air.(c) "Heat output" means the enthalpy of a water heater's working fluid output.(d) "Natural gas-fired water heater" means a device that heats water:(i) using natural gas combustion;(ii) for use external to the device at a pressure that is less than or equal to 160 pounds per square inch gage; and(iii) to a thermostatically controlled temperature less than or equal to: (A) 210 degrees Fahrenheit; or(e) "ppm" means parts of Nitrogen Oxide per million parts of water heater air output.(f) "Recreational vehicle" means the same as that term is defined in Section 13-14-102.(2) On and after July 1, 2018, a person may not sell or install a natural gas-fired water heater with an emission rate greater than the following limits: (a) except as provided in Subsection (6), for a water heater that has a heat input of less than or equal to 75,000 BTU per hour that is not installed in a mobile home, a limit of: (i) 10 nanograms per Joule of heat output; or(ii) 15 ppm, corrected to 3% oxygen;(b) for a water heater that has a heat input of greater than 75,000 BTU per hour and less than 2,000,000 BTU per hour that is not installed in a mobile home, a limit of: (i) 14 nanograms per Joule of heat output; or(ii) 20 ppm, corrected to 3% oxygen;(c) for a water heater installed in a mobile home, a limit of: (i) 40 nanograms per Joule of heat output; or(ii) 55 ppm, corrected to 3% oxygen;(d) for a pool or spa water heater with a heat input that is less than or equal to 400,000 BTU per hour, a limit of:(i) 40 nanograms per Joule of heat output; or(ii) 55 ppm, corrected to 3% oxygen; and(e) for a pool or spa water heater with a heat input of greater than 400,000 BTU per hour and less than 2,000,000 BTU per hour, a limit of:(i) 14 nanograms per Joule of heat output; or(ii) 20 ppm, corrected to 3% oxygen.(3) A water heater manufacturer shall use California South Coast Air Quality Management District Method 100.1 to calculate the emissions rate of a water heater subject to this section.(4) A water heater manufacturer shall display on a water heater subject to this section, as a permanent label, the model number and the Nitrogen Oxide emission rate of the water heater.(5) The requirements of this section do not apply to: (a) a water heater using a fuel other than natural gas;(b) a water heater used in a recreational vehicle;(c) a water heater manufactured in the state for sale and shipment outside of the state; or(d) a water heater manufactured before July 1, 2018.(6) A person may sell or install a natural gas-fired water heater with an emission rate greater than the limits established in Subsection (2)(a) if: (a) the water heater is replacing a water heater of equal BTUs per hour;(b) there is not available for purchase in the United States a water heater that: (i) has an input of equal BTUs per hour as the water heater being replaced; and(ii) meets the limits established in Subsection (2)(a); and(c) the purpose of the water heater is to heat water and provide space heating.Amended by Chapter 136, 2020 General Session ,§ 3, eff. 7/1/2020.Amended by Chapter 236, 2017 General Session ,§ 3, eff. 5/9/2017.Added by Chapter 249, 2016 General Session ,§ 42, eff. 7/1/2016.