Statutes, codes, and regulations
District Of Columbia Administrative Code
Title 12 - CONSTRUCTION CODES SUPPLEMENT OF 2017Subtitle 12-I - ENERGY CONSERVATION CODE SUPPLEMENT OF 2017- COMMERCIAL PROVISIONS (12-I[CE] DCMR)
Section 12-I6 - HEATING, VENTILATING, AND AIR CONDITIONING
Section 12-I6.4 - MANDATORY PROVISIONS

D.C. Mun. Regs. tit. 12, 12-I6.4

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Current through Register Vol. 71, No. 36, September 6, 2024
Section 12-I6.4 - MANDATORY PROVISIONS

Insert new Sections 6.4.1.1.1 and 6.4.1.1.2 in ASHRAE 90.1 in the Energy Conservation Code-Commercial Provisions to read as follows:

6.4.1.1.1

Higher-Efficiency Requirements. All building projects complying with the Alternate Renewables Approach in Section 13.1.1.2 shall comply with the equipment efficiency requirements in Section 13.1.1.2 in place of Tables 6.8.1-1 through 6.8.1-11 and shall comply with the applicable ENERGY STAR heating and cooling requirements in Section 10.11.2.

6.4.1.1.2

Heat Pump Requirement. For spaces which are both heated and cooled using unitary systems per Tables 6.8.1-1 through 6.8.1-2, and Table 6.8.1-4, heating shall also include use of a heat pump for primary heating. Packaged systems shall not include electric resistance heating unless used as back-up heat and controlled per Section 6.4.3.5.

Exceptions:

a. Water cooled systems in Tables 6.8.1-1 and 6.8.1-2 where no additional water heating is provided during the heating season.
b. In retrofit applications and additions, where the use of a central heating system is already being used such as hydronic heating or central forced air furnace.

Strike Section 6.4.3.8 of ASHRAE 90.1 in its entirety and insert new Sections 6.4.3.8 and 6.4.3.8.1 in its place in the Energy Conservation Code-Commercial Provisions to read as follows:

6.4.3.8

Ventilation Controls for High-Occupancy Areas. Demand control ventilation (DCV) shall be provided for densely occupied spaces served by systems with one or more of the following:

a. Air-side economizer.
b. Automatic modulating control of outdoor air dampers.
c. Design outdoor airflow greater than 1000 cfm.

Exceptions to Section 6.4.3.8:

1. Systems with the exhaust air energy recovery complying with Section 6.5.6.1.
2. Systems with a design outdoor airflow less than 750 cfm (375 L/s).
3.Spaces where more than 75% of the space design outdoor airflow is utilized as makeup air or transfer air to provide makeup air for other space(s).
4.Spaces with one of the following occupancy categories as defined in ASHRAE Standard 62.1 : cells in correctional facilities; daycare sickrooms; science laboratories; barbers; beauty and nail salons; and bowling alleys.
6.4.3.8.1

Design of DCV System. The DCV system shall be designed to be in compliance with Section 6.2.7 of ANSI/ASHRAE Standard 62.1-2013. Occupancy assumptions shall be shown in the design documents for spaces provided with DCV. All CO2 sensors used as part of a DCV system or any other system that dynamically controls outdoor air shall meet the following requirements:

a.Spaces with CO2 sensors or air-sampling probes leading to a central CO2 monitoring station shall be provided with at least one sensor or probe for each 10,000 ft (1000 m) of floor space. Sensors or probes shall be installed between 3 and 6 ft (1 and 2 m) above the floor.
b. CO2 sensors shall be accurate to ± 50 ppm at 1000 ppm.
c.Outdoor air CO2 concentrations shall be determined one of the following:
1.Outdoor air CO2 concentrations shall be dynamically measured using a CO2 sensor.
2. When documented statistical data are available on the local ambient CO2 concentrations, a fixed value typical of the location where the building is located shall be allowed in lieu of an outdoor sensor.
d. Occupant CO2 generation rate assumptions shall be shown in the design documents.

Strike Section 6.4.4.1.2 of ASHRAE 90.1 in its entirety and insert a new Section 6.4.4.1.2 in its place in the Energy Conservation Code-Commercial Provisions to read as follows:

6.4.4.1.2

Duct and Plenum Insulation. All supply and return ducts and plenums installed as part of an HVAC air distribution system shall be thermally insulated in accordance with Tables 6.8.2-1 and 6.8.2-2. Building projects complying with Chapter 13 shall instead reference Normative Appendix A, ASHRAE 189.1-2014, Table A-2, Minimum Duct Installation R-Value Heating and Cooling-Only Supply Ducts and Return Ducts (I-P), and Table A-3, Minimum Duct Installation R-Value Combined Heating and Cooling Supply Ducts and Return Ducts (I-P).

Exceptions:

1. Factory-installed plenums, casings, or ductwork furnished as a part of HVAC equipment tested and rated in accordance with Section 6.4.1.
2. Ducts or plenums located in conditioned spaces.
3. For runouts less than 10 ft in length to air terminals or air outlets, the rated Rvalue of insulation need not exceed R 3.5.
4. Backs of air outlets and outlet plenums exposed to unconditioned or indirectly conditioned spaces with face areas exceeding 5 ft2 need not exceed R-2; those 5 ft2 or smaller need not be insulated.

Strike Section 6.4.4.1.3 of ASHRAE 90.1 in its entirety and insert a new Section 6.4.4.1.3 in its place in the Energy Conservation Code-Commercial Provisions to read as follows:

6.4.4.1.3

Piping Insulation. Piping, including but not limited to, all branch piping and piping components, shall be thermally insulated in accordance with Tables 6.8.3-1 and 6.8.3-2.

Exceptions:

1. Factory-installed piping within HVAC equipment tested and rated in accordance with Section 6.4.1.
2. Piping that conveys fluids having a design operating temperature range between 60°F and 105°F, inclusive.
3. Piping that conveys fluids that have not been heated or cooled through the use of fossil fuels or electricity (such as roof and condensate drains, domestic cold-water supply, natural-gas piping).
4. Where heat gain or heat loss will not increase energy usage (such as liquid refrigerant piping).
5. In piping 1 inch (2.54 cm) or less, insulation is not required for strainers, control valves, and balancing valves.

Strike Table 6.5.1-1 and 6.5.1-2 of ASHRAE 90.1 in their entirety and insert new Table 6.5.1-1 in the Energy Conservation Code in their place to read as follows:

TABLE 6.5.1-1 Minimum Fan-Cooling Unit Size for which an Economizer is Required for Comfort Cooling

Climate Zones

Cooling Capacity for Which an Economizer is Required

1a, 1b

No economizer requirement

2a, 2b, 3a, 4a, 5a, 6a

3b, 3c, 4b, 4c, 5b, 5c, 6b, 7, 8

> 33,000 Btu/ha

a. Where economizers are required, the total capacity of all systems without economizers shall not exceed 480,000 Btu/h (140 kW) per building or 10% of the building's installed cooling capacity, whichever is greater.

D.C. Mun. Regs. tit. 12, 12-I6.4

Final Rulemaking published at 67 DCR 5679 (5/29/2020)