SUMMARY OF THE
SCAQMD RULES

RULE 1146.2
New NOx Emission Standards for Boilers,
Water Heaters and Pool Heaters
Reference: http Ref: http://www.aqmd.gov/rules/html/r1146-2.html

Summary
Rule 1146.2 establishes stringent new NOx emission standards for commercial water heaters and small boilers in the South Coast District. The rule affects new units with rated heat inputs of 75,000 to 2,000,000 BTUH, and existing units with rated heat inputs of 400,001 to 2,000,000 BTUH.

Applicable Area
Rule 1146.2 applies to the South Coast District, comprising all or portions of Los Angeles, Orange, Riverside and San Bernardino counties.
Requirements for New Units
The following NOx emission standards apply to the manufacture and sale of new units in the District, on or after the stated effective dates:
BTUH Input
Effective Date
NOx Standard
75,000-400,000
January 1, 2000
Less than 55 ppm
400,001-2,000,000
January 1, 2001
Less than 30 ppm
Requirements for Existing Units
BTUH
Year
Manufactured
Effective
Date
NOx Standard
75,000-400,000
Exempt
400,001-1,000,000
All
January 1, 2006
Less than
30 ppm
1,000,001-2,000,000
1992 or later
January 1, 2005
1,000,001-2,000,000
Before 1992
July 1, 2002
Units operating in the District, must be retrofitted or replaced to comply with the new NOx emission standards by the stated effective dates if the unit is one that consumes over 9,000 therms per year. This equals 900 hours of operation per year for a 1,000,000 BTUH boiler firing at full rate. Low usage units, such as some heating boilers and seasonal use pool heaters, are exempt from the retrofit/replacement requirement.