2016 Utah Code
Title 15A - State Construction and Fire Codes Act
Chapter 6 - Additional Construction Requirements
Part 1 - Nitrogen Oxide Emission Limits for Natural Gas-fired Water Heaters
Section 102 - Nitrogen Oxide emission limits for natural gas-fired water heaters.

Effective 7/1/2016
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
      • (B) 99 degrees Celsius.
  • (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) Subject to Subsection (6), a person may not sell or install a natural gas-fired water heater with an emission rate greater than the following limits:
  • (a) 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) 10 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) 20 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) 55 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) Subsection (2) applies to the sale or installation of a water heater on or after July 1, 2018.

Enacted by Chapter 249, 2016 General Session