Sec. 508.5. Additional requirements for residential buildings of not more than three stories, containing four or fewer dwelling units: energy efficiency specifications and performance specifications  


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  • A residential building of not more than three stories, containing four or fewer dwelling units, shall meet or exceed:
    (a) the following energy efficiency specifications:
    (1) HERS information: achieved either an expanded HERS score of 86 or higher or a HERS index of 70 or lower, using a rating software tool that has been approved by the authority and that generates a rating report containing the following information:
    (i) the expanded HERS score or HERS index;
    (ii) the estimated quantity of energy to be used annually for purposes of space heating, space cooling, water heating, lighting, operating household appliances, and any other use of energy, and an estimate of the annual energy cost for each purpose and for the residential building as a whole;
    (iii) the street address or recorded real property identifier;
    (iv) the name of the rater;
    (v) the date that the rating report was prepared; and
    (vi) the rating software program and version number used to calculate the rating; and
    (2) ceiling fan and light kit: if a ceiling fan(s) has been installed, has installed only a ceiling fan(s) that meets the minimum energy efficiency levels set forth in Table 4 of this section, and only a light kit(s) that meets the minimum efficiency requirements set forth in Table 1 of this Part tested by the manufacturer in accordance with the test procedures set forth in the ENERGY STAR® Testing Facility Guidance Manual: Building a Testing Facility and Performing the Solid State Test Method for ENERGY STAR® Qualified Ceiling Fans, Version 1.0, Draft 1, June 20, 2002; and
    Table 4: Minimum Efficiency Requirements for Ceiling Fans
    Fan SpeedMinimum AirflowEfficiency Requirement
    Low1,250 cubic feet per minute155 cubic feet per minute/watt
    Medium3,000 cubic feet per minute100 cubic feet per minute/watt
    High5,000 cubic feet per minute75 cubic feet per minute/watt
    (3) central air conditioner: if a central air conditioner has been installed:
    (i) has installed in residential buildings, only a central air conditioner(s) that has a 14.5 SEER (as defined in Table 5 of this section) and a 12 EER (as defined in Table 5 of this section), or higher, for split systems, and that has a 14 SEER (as defined in Table 5 of this section) and 11 EER (as defined in Table 5 of this section), or higher, for single package systems; a central air conditioner(s) shall meet the energy efficiency requirements set forth in Table 5 determined in accordance with the test procedures set forth in Table 5 of this section; and
    (ii) has had the total supply air flow rates tested and verified by a technician to determine that the ducted distribution system delivers ±15 percent of room design airflow, in accordance with section 5.2.2 Acceptable Procedures, of ANSI/ACCA Standard 5 QI-2007, for each room being conditioned; and
    Table 5: Minimum Efficiency Levels for Central Air Conditioners
    TypeMinimum EfficiencyTest Procedure for Determining Efficiency Level
    Central Air Conditioner (split system)14.5 SEERa/ 12 EERbANSIc / AHRId 210/240-2008
    Central Air Conditioner (single package system)14.5 SEERa/ 11 EERbANSIc / AHRId 210/240-2008
    a SEER (Seasonal Energy Efficiency Ratio) means the total cooling output of a central air conditioner in Btus during its normal annual usage period for cooling divided by the total electric energy input in watt-hours during the same period
    b EER (Energy Efficiency Ratio) means the ratio of net cooling capacity in Btus per hour to the total rate of electric input in watts, under designated operating conditions
    c ANSI means the American National Standards Institute
    d AHRI means the Air-Conditioning, Heating, and Refrigeration Institute (formerly ARI)
    (4) domestic water heater:
    (i) has installed only a domestic water heater(s) that has a first-hour rating that meets the capacity for the calculated peak hour demand within one-to-two gallons; and
    (ii) if an oil-fired domestic water heater has been installed, has installed only an oil-fired domestic water heater(s) that has a flame retention burner; and
    (iii) if a domestic water heater using natural gas or propane has been installed, has installed only a domestic water heater(s) using natural gas or propane that meets the minimum energy efficiency requirements set forth in Table 6 of this section determined in accordance with the test procedures set forth in 10 Code of Federal Regulations (CFR) 430; and
    (iv) if a natural gas tankless water heater has been installed, has installed only a natural gas tankless water heater that meets the minimum energy efficiency requirements set forth in Table 6 of this section determined in accordance with 10 Code of Federal Regulations (CFR) 430; and
    Table 6: Minimum Energy Factors for Domestic Water Heaters
    Rated Storage Capacity (in gallonsMinimum EFa for Natural Gas or Propane Water HeatersMinimum EF for Electric Water Heaters
    300.620.94
    400.620.93
    500.620.92
    750.540.90
    1000.490.87
    Natural Gas Tankless Water Heaters0.82
    a EF (Energy Factor) means the ratio of useful energy output from a domestic water heater to the total amount of energy delivered to the domestic water heater.
    (5) heating equipment - heat pumps and furnaces:
    (i) has installed a heating system(s) that uses less than 300,000 Btus per hour and meets or exceeds the minimum efficiency requirements set forth in Table 7 of this section determined in accordance with the test procedures set forth in Table 7 of this section; and
    (ii) if a heat pump is installed, has had the total supply air flow rates tested and verified by a technician to determine that the ducted distribution system delivers ±15 percent of room design airflow, in accordance with ANSI/ACCA Standard 5 QI-2007, for each room being conditioned; and
    Table 7: Minimum Efficiency Levels for Primary Residential Heating Systems
    TypeMinimum EfficiencyTest Procedure for Determining Efficiency Level
    Furnace—Natural GasAFUEa 92%10 CFR 430, Appendix N
    Furnace—Fuel OilAFUEa 85%10 CFR 430, Appendix N
    Boiler—Hot Water or SteamAFUEa 85%10 CFR 430
    Air-Source Heat Pump—Split System14.5 SEERb/12 EERe/8.2 HSPFfANSIc/AHRId 210/240-2008
    Air-Source Heat Pump—Single Package14 SEERb/11 EERe/8.0 HSPFfANSIc/AHRId 210/240-2008
    Ground Source Heat Pump—Closed Loop14.1 EERe/3.3 COPhISOg 13256-1
    Ground Source Heat Pump—Open Loop16.2 EERe/3.6 COPhISOg 13256-1
    Ground Source Heat Pump—Direct Expansion15 EERe/3.5 COPhANSIc/AHRId 870-2005
    Combination Water/Space Heater0.73 CAEiANSIe/ASHRAEj 124-1991
    a AFUE (Annual Fuel Utilization Efficiency) means the ratio of annual output energy to annual input energy which includes any non-heating season pilot input loss, and for gas or oil-fired furnaces or boilers, does not include electrical energy.
    b SEER (Seasonal Energy Efficiency Ratio) means the total cooling output of a central air conditioner in Btus during its normal annual usage period for cooling divided by the total electric energy input in watt-hours during the same period
    c ANSI means the American National Standards Institute
    d AHRI means the Air-Conditioning, Heating, and Refrigeration Institute (formerly ARI)
    e EER (Energy Efficiency Ratio) means the ratio of net cooling capacity in Btus per hour to the total rate of electric input in watts, under designated operating conditions
    f HSPF (Heating Seasonal Performance Factor) means the total heating output of a heat pump during its normal annual usage period for heating divided by the total electric energy input during the same period
    g ISO means the International Organization for Standardization
    h COP (Coefficient of Performance) means a unitless ratio of the rate of heat removal or heat delivery to the rate of energy input, in consistent units, for a complete refrigerating or heat pump system under designated operating conditions
    i CAE (Combined Annual Efficiency) means the overall efficiency of a heating system in providing both space heating and water heating in KBtu/h
    j ASHRAE means the American Society of Heating, Refrigerating, and Air-Conditioning Engineers
    (6) ventilation fans:
    (i) has installed only ventilation fans that meet the minimum energy efficiency levels set forth in Table 8 of this section determined in accordance with the test procedures set forth in Table 8 of this section; and
    (ii) has installed only combination ventilation fan(s) that meets the efficiency specifications set forth in Table 8 of this section and the light source criteria set forth in Table 9 of this section.
    Table 8: Minimum Efficiency Requirements for Ventilation Fans Using Home Ventilating Institute Publications 915, 916 and 920 Test Criteria for Ventilation Fans
    ProductAirflowEfficiency Requirement
    Range HoodsUp to 500 cubic feet per minute (max)2.8 cubic feet per minute/watt
    Bathroom and Utility Room Fans10-80 cubic feet per minute1.4 cubic feet per minute/watt
    Bathroom and Utility Fans90-130 cubic feet per minute2.8 cubic feet per minute/watt
    Bathroom and Utility Fans140-500 cubic feet per minute (max)2.8 cubic feet per minute/watt
    In-Line Ventilating Fans2.8 cubic feet per minute/watt
    Table 9: Light Source Criteria for Combination Ventilation Fans
    Performance CharacteristicSpecification
    System Efficiency per lamp ballast combination, Lumens per Watt (LPW)≥ 46 LPW for all lamp types below 30 total listed lamp watts ≥ 60 LPW for all lamp types that are ≤ 24 inches and ≥ 30 listed lamp watts ≥ 70 LPW for all lamp types that are ≥ 24 inches and ≥ 30 listed lamp watts
    Maximum Total Lamp Wattage (excluding night lights)≤ 50 Watts
    Maximum Night Light Wattage≤ 4 Watts
    (b) A residential building of not more than three stories in height above grade, containing four or fewer dwelling units, shall have met or exceeded the following performance specifications:
    (1) building envelope: has installed a building envelope that has five or fewer air changes per hour (ACH) measured at a pressure difference of 50 pascals, using a blower door; and
    (2) duct leakage:
    (i) has conducted duct leakage testing using the blower door subtraction method, flow hood test, or duct pressure test, and such leakage shall not exceed 6 cubic feet per minute to outdoors at a pressure difference of 25 pascals per 100 square feet of conditioned floor area; or
    (ii) has only installed ducts and a furnace or heat pump in conditioned space and has determined that building envelope leakage using a blower door test is less than or equal to 3 air changes per hour (ACH) at a pressure difference of 50 pascals; and
    (3) mechanical ventilation:
    (i) has installed only an automatically controlled mechanical ventilation system that meets the minimum ventilation requirements set forth in Table 10 of this section determined in accordance with Table 10 of this section, using the calculation methods prescribed by ANSI/ASHRAE 62.2-2007; and
    (ii) has installed only a mechanical ventilation system that operates automatically, without occupant intervention, exhausts to the exterior of the building, and has a readily available and accessible override control.
    Table 10: Minimum Ventilation Requirements Using ANSIa/ASHRAEb 62.2-2007
    Minimum Ventilation Requirement (cubic feet per minute)
    Square Footage Number of Bedrooms
    1234567
    100025334048556370
    1001150030384553606875
    1501200035435058657380
    2001250040485563707885
    2501300045536068758390
    3001350050586573808895
    35014000556370788593100
    40014500606875839098105
    450150006573808895103110
    5001550070788593100108115
    5501600075839098105113120
    a ANSI means the American National Standards Institute
    b ASHRAE means the American Society of Heating, Refrigerating, and Air-Conditioning Engineers