SJVUAPCD 3/19/2009 4902 - 1 RULE 4902 RESIDENTIAL WATER HEATERS (A dopted June 17, 1993; Amended March 19, 2009)

1.0 Purpose

The purpose of this rule is to limit oxides of nitrogen emissions from residential water
heaters.

2.0 Applicability

This rule applies to manufact urers, distributors, retailers, and installers of PUC quality natural gas-fired residential water heaters w ith heat input rates less than or equal to 75,000 Btu/hr.

3.0 Definitions

3.1 Air Pollution Control Officer (APCO): As defined in Rule 1020 (Definitions).

3.2 California Public Utility Commission (P UC) Quality Natural Gas: Any gaseous fuel, gas-containing fuel where the sulf ur content is no mo re than one-fourth (0.25) grain of hydrogen sulfide per one hundred (100) standard cubic feet and no more than five (5) grains of total sulfur per one hundred (100) standard cubic feet. PUC quality natural gas also m eans high methane gas of at least 80% methane by volume.

3.3 Heat Output: The product obtained by multiplying the recovery efficiency, as defined by Section 6.1. 3 of the Code of Federal Re gulation, Title 10, Part 430, Subpart B, Appendix E, by the input rating of the water heater.

3.4 Input Rating: The amount of ener gy a water heater c onsumes in one hour (Btu/Hour).

3.5 Instantaneous Water Heater: A water h eater that heats water only when it flows through a heat exchanger.

3.6 Mobile Home Water Heater: A clos ed vessel manufactured exclusively for
mobile home use in which wa ter is heated by combustion of gaseous fuel and is
withdrawn for use external to the ve ssel at pressures not exceeding 160 psig, including the apparatus by which heat is generated and all c ontrols and devices
necessary to prevent water temper atures from exceeding 210oF (99oC).

3.7 Pool Heater: A water heater desi gned to heat a pool, hot tub, or spa.SJVUAPCD 3/19/2009 4902 - 2 3.8 Water Heater: A closed vessel, in wh ich water is heated by the combustion of PUC quality natural gas and is withdraw n for use external to the vessel at pressures not exceeding 160 psig, includi ng the apparatus by which heat is generated and all controls and devices necessary to pr event water temperatures from exceeding 210 ° F (99oC).

4.0 Exemptions

4.1 PUC quality natural gas-fired water heater s with rated heat input of greater than 75,000 Btu per hour.

4.2 Water heaters using fuels other than PUC quality natural gas.

4.3 Pool heaters. On and after January 1, 2010, pool heaters shall comply with all applicable requirements of this rule.

4.4 Water heaters used exclusively in recreational vehicles.

5.0 Requirements

5.1 On and before December 31, 2009, no person shall sell, install or offer for sale within the District any PU C quality natural gas-fired water heater manufactured after December 17, 1993, except for mob ile home water heaters subject to Section 5.2, unless the water heater is certified pursuant to Section 6.1 to a NOx emission level of less than or equa l to 40 nanograms of nitrogen oxides (calculated as NO 2 ) per Joule of heat output.

5.2 No person shall manufacture for sale, distribute, sell, offer for sale, or install within the District any PUC quality natural gas-fired mobile home water heater unless the water heater is certified pursu ant to Section 6.1 to a NOx emission level of less than or equal to 40 nanograms of NOx ( calculated as NO 2 ) per joule of heat output.

5.3 On and after January 1, 2010, no person shall manufact ure for sale, distribute, sell, offer for sale, or install within the District any PUC quality natural gasfired pool heater unless the water heater is certified pursuant to Section 6.1 to a NOx emission level of less than or equa l to 40 nanograms of NOx (calculated as
NO 2 ) per joule of heat output.

5.4 On and after January 1, 2010, no person shall manufact ure for sale, distribute, sell, offer for sale, or install within the District any PUC quality natural gasfired water heater, excluding mobile hom e water heaters, instantaneous water heaters, and pool heaters, unless the wate r heater is certified pursuant to SectionSJVUAPCD 3/19/2009 4902 - 3 6.1 to a NOx emission level of less th an or equal to 10 nanograms of NOx (calculated as NO 2 ) per joule of heat output.

5.5 On and after January 1, 2012, no person shall manufact ure for sale, distribute, sell, offer for sale, or install within the District any PUC quality natural gasfired instantaneous water h eater unless the water heater is certified pursuant to
Section 6.1 to a NOx emission level of less than or equal to 14 nanograms of NOx (calculated as NO 2 ) per joule of heat output.

6.0 Administrative Requirements

6.1 Certification

6.1.1 Each water h eater undergoing testing shall be operated in accordance
with Section 2.4 of American Na tional Standards AN SI Z21.10.1-1990, Z21.10.3-2004, or Z21.56- 2006, as applicable, at normal test pressure, input rates, and with a five-foot exhaust stack installed during the nitrogen oxides emission tests.

6.1.2 The manufacturer shall demonstrat e that each water heater model subject to the requirements of Section 5.0 has been tested in accordance with EPA Reference Test Method 7E, 40 CFR Part 60, Appendix A.

6.1.3 The following formula shall be used to calculate the emissions of NO
x in nanograms of NO x per Joule of heat output:

N = (4.566 x 10 4 x P x U)/(H x C x E)

Where:

N = NO X emission rate in nanograms of NO X emitted per Joule of heat output
4.566 x 10 4 = unit conversion factor (ppm to nanograms and Btu to Joules)
P = Concentration of NO X in the flue gas in parts per million (volume) U = Dry volume percent of CO 2 in flue gas necessary
for stoichiometric combustion H = Gross heating value of the gas, Btu/Cu ft (at 60 ° F and 30" Hg) C = Dry volume percent of CO 2 in flue gas E = Recovery efficiency, percentage, as defined in
Section 6.1.3 of the Code of Federal Regulation, Title 10, Part 430, Subpart B, Appendix ESJVUAPCD 3/19/2009 4902 - 4 6.1.4 The manufacturer may submit to the APCO an approved South Coast Air Quality Management District Rule 1121 (Control of Nitrogen Oxides From Residential Type, Natural Ga s-Fired Water Heaters), Ventura County Air Pollution Control District Rule 74.11 (Natural Gas-Fired
Residential Water Heaters – Control of NOx), or Bay Area Air Quality Management District Re gulation 9 Rule 6 (Nitrogen Oxides Emissions
from Natural Gas-Fired Boilers and Water Heaters) certification in lieu of conducting duplicative certification tests pursuant to Section 6.1.

6.1.5 Upon request of the APCO, each manufacturer shall submit to the APCO a statement certifying the water heater s subject to this rule are in compliance with the provisions of Sec tion 5.0. The statement shall be signed, dated and shall attest to th e accuracy of all in formation. The
statement shall include:

6.1.5.1 Name and addr ess of manufacturer, 6.1.5.2 Brand name, 6.1.5.3 Model number, as it appears on the water heater rating plate,
and 6.1.5.4 Heat input rating, Btu/hr.

6.2 For units subject to Section 5.0, th e manufacturer shall display the following on the shipping carton and rating plate of each unit:

6.2.1 the model number, 6.2.2 the date of manufacture, and
6.2.3 the certification status.