CS-v5 EQp2: Fundamental Air Quality Required
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Credit language
© Copyright U.S. Green Building Council, Inc. All rights reserved.
Intent
To design for above-average indoor air quality to support occupant health and well-being.
Requirements
Investigate Regional and Local Air Quality
Investigate outdoor air quality in accordance with ASHRAE Standard 62.1-2022, Sections 4.1–4.3.
AND
Ventilation and Filtration Design
Meet the requirements of ASHRAE Standard 62.1-2022, Sections 5 and 6. Use the ventilation rate procedure, the IAQ procedure, the natural ventilation procedure, or a combination thereof. Where the ventilation rate procedure or IAQ procedure are used, comply with the following additional provisions:
- Filtration: Each central HVAC system that supplies outdoor air and/or recirculated air to regularly occupied spaces must meet one of the following:
- Minimum efficiency reporting value (MERV) of 13, in accordance with ASHRAE Standard 52.2–2017; OR
- Equivalent filtration media class of ePM1 50%, as defined by ISO 16890-2016, Particulate Air Filters for General Ventilation — Determination of the Filtration Performance; OR
- In-room air-cleaning systems;
- Systems tested for effectiveness and safety per ASHRAE Standard 241-2023, Section 7.4 (and Normative Appendix A). If treating for particles and gases, use systems tested for effectiveness per ASHRAE 62.1-2022, Addendum N. If treating for infectious aerosols, use systems tested for effectiveness per ASHRAE Standard 241-2023, Section 7.
- Outdoor air measurement: Provide outdoor airflow measurement devices for all mechanical ventilation systems with outdoor air intake flow greater than 1,000 cfm (472 L/s).
Healthcare
- For healthcare spaces, meet the requirements of Sections 6–10 of ASHRAE Standard 170-2021.
Residential
- For residential spaces, follow the additional dwelling unit provisions below.
Dwelling Unit Provisions
If the project building contains residential units, each dwelling unit must meet all the following requirements:
- Design and install a dwelling-unit mechanical ventilation system that complies with ASHRAE 62.2-2022, Sections 4, 6.6, and 6.7. Supply and balanced mechanical ventilation systems must be designed and constructed to provide ventilation air directly from the outdoors. Mechanical ventilation systems are not required when the project meets the exception detailed in ASHRAE 62.2-2022, Section 4.1.1.
- Design and install local mechanical exhaust systems in each kitchen and bathroom, including half baths, that comply with ASHRAE 62.2-2022, Sections 5 and 7. Exhaust air to the outdoors. Do not route exhaust ducts to terminate in attics or interstitial spaces. Recirculating range hoods or recirculating over-the-range microwaves do not satisfy the kitchen exhaust requirements. For exhaust hood systems capable of exhausting in excess of 400 cubic feet per minute (188 liters per second), provide makeup air at a rate approximately equal to the exhaust air rate. Makeup air systems must have a means of closure and be automatically controlled to start and operate simultaneously with the exhaust system. Use ENERGY STAR labeled bathroom exhaust fans in all bathrooms (including half baths) or performance equivalent for projects outside the U.S. An HRV or ERV may be used to exhaust single or multiple bathrooms if it has an efficacy level meeting the ENERGY STAR Technical Specifications for Residential Heat-Recovery Ventilators and Energy-Recovery Ventilators (H/ERVs), version 2.3 as certified by the Home Ventilating Institute.
- Unvented combustion appliances (ovens and ranges excluded) are not allowed.
- A carbon monoxide (CO) monitor must be installed on each floor of each dwelling unit, hard-wired with a battery backup. CO monitors are required in all types of units, regardless of the type of equipment installed in the unit.
- Any indoor fireplaces and woodstoves must have solid glass enclosures or doors that seal when closed. Any indoor fireplaces and woodstoves that are not closed combustion or power-vented must pass a backdraft potential test to ensure that depressurization of the combustion appliance zone is less than 5 Pa.
- Space- and water-heating equipment that involves combustion must be designed and installed with closed combustion (i.e., sealed supply air and exhaust ducting) or with power-vented exhaust or located in a detached utility building or open-air facility.
AND
Entryway System Design
Install permanent entryway systems to capture dirt and particulates entering the building at primary exterior entrances. There is no length requirement for entryway systems.
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Credit language
© Copyright U.S. Green Building Council, Inc. All rights reserved.
Intent
To design for above-average indoor air quality to support occupant health and well-being.
Requirements
Investigate Regional and Local Air Quality
Investigate outdoor air quality in accordance with ASHRAE Standard 62.1-2022, Sections 4.1–4.3.
AND
Ventilation and Filtration Design
Meet the requirements of ASHRAE Standard 62.1-2022, Sections 5 and 6. Use the ventilation rate procedure, the IAQ procedure, the natural ventilation procedure, or a combination thereof. Where the ventilation rate procedure or IAQ procedure are used, comply with the following additional provisions:
- Filtration: Each central HVAC system that supplies outdoor air and/or recirculated air to regularly occupied spaces must meet one of the following:
- Minimum efficiency reporting value (MERV) of 13, in accordance with ASHRAE Standard 52.2–2017; OR
- Equivalent filtration media class of ePM1 50%, as defined by ISO 16890-2016, Particulate Air Filters for General Ventilation — Determination of the Filtration Performance; OR
- In-room air-cleaning systems;
- Systems tested for effectiveness and safety per ASHRAE Standard 241-2023, Section 7.4 (and Normative Appendix A). If treating for particles and gases, use systems tested for effectiveness per ASHRAE 62.1-2022, Addendum N. If treating for infectious aerosols, use systems tested for effectiveness per ASHRAE Standard 241-2023, Section 7.
- Outdoor air measurement: Provide outdoor airflow measurement devices for all mechanical ventilation systems with outdoor air intake flow greater than 1,000 cfm (472 L/s).
Healthcare
- For healthcare spaces, meet the requirements of Sections 6–10 of ASHRAE Standard 170-2021.
Residential
- For residential spaces, follow the additional dwelling unit provisions below.
Dwelling Unit Provisions
If the project building contains residential units, each dwelling unit must meet all the following requirements:
- Design and install a dwelling-unit mechanical ventilation system that complies with ASHRAE 62.2-2022, Sections 4, 6.6, and 6.7. Supply and balanced mechanical ventilation systems must be designed and constructed to provide ventilation air directly from the outdoors. Mechanical ventilation systems are not required when the project meets the exception detailed in ASHRAE 62.2-2022, Section 4.1.1.
- Design and install local mechanical exhaust systems in each kitchen and bathroom, including half baths, that comply with ASHRAE 62.2-2022, Sections 5 and 7. Exhaust air to the outdoors. Do not route exhaust ducts to terminate in attics or interstitial spaces. Recirculating range hoods or recirculating over-the-range microwaves do not satisfy the kitchen exhaust requirements. For exhaust hood systems capable of exhausting in excess of 400 cubic feet per minute (188 liters per second), provide makeup air at a rate approximately equal to the exhaust air rate. Makeup air systems must have a means of closure and be automatically controlled to start and operate simultaneously with the exhaust system. Use ENERGY STAR labeled bathroom exhaust fans in all bathrooms (including half baths) or performance equivalent for projects outside the U.S. An HRV or ERV may be used to exhaust single or multiple bathrooms if it has an efficacy level meeting the ENERGY STAR Technical Specifications for Residential Heat-Recovery Ventilators and Energy-Recovery Ventilators (H/ERVs), version 2.3 as certified by the Home Ventilating Institute.
- Unvented combustion appliances (ovens and ranges excluded) are not allowed.
- A carbon monoxide (CO) monitor must be installed on each floor of each dwelling unit, hard-wired with a battery backup. CO monitors are required in all types of units, regardless of the type of equipment installed in the unit.
- Any indoor fireplaces and woodstoves must have solid glass enclosures or doors that seal when closed. Any indoor fireplaces and woodstoves that are not closed combustion or power-vented must pass a backdraft potential test to ensure that depressurization of the combustion appliance zone is less than 5 Pa.
- Space- and water-heating equipment that involves combustion must be designed and installed with closed combustion (i.e., sealed supply air and exhaust ducting) or with power-vented exhaust or located in a detached utility building or open-air facility.
AND
Entryway System Design
Install permanent entryway systems to capture dirt and particulates entering the building at primary exterior entrances. There is no length requirement for entryway systems.