Appendix: Air

 

A01.1 – Meet thresholds for particulate matter
The following thresholds are met:

1. PM2.5 less than 15 μg/m3.
2. PM10 less than 50 μg/m3.

 

A01.2 – Meet thresholds for organic gases
The following thresholds are met:

1. Formaldehyde less than 27 ppb.
2. Individual component VOCs less than or equal to the limits listed in the standard.

Compound Name	CAS No.	Allowable Concentration (μg/m3)
Benzene	71-43-2	30
Carbon disulfide	75-15-0	400
Carbon tetrachloride	56-23-5	20
Chlorobenzene	108-90-7	500
Chloroform	67-66-3	150
Dichlorobenzene (1, 4-)	106-46-7	400
Dichloroethylene (1,1)	75-35-4	35
Ethylbenzene	100-41-4	1000
Hexane (n-)	110-54-3	3500
Isopropyl alchohol	67-63-0	3500
Methyl chloroform	71-55-6	500
Methylene chloride	75-09-2	200
Methyl tert-butyl ether	1634-04-4	4000
Styrene	100-42-5	450
Tetrachloroethene	127-18-4	17.5
Toluene	108-88-3	150
Trichloroethylene	79-01-6	300
Vinyl acetate	108-05-4	100
Xylene (m, o, p combined)	108-38-3 + 95-47-6 + 106-42-3, 179601-23-1 + 95-47-6, or 1330-20-7	350

 

A01.3 – Meet thresholds for inorganic gases
The following are met:

1. Carbon monoxide less than 9 ppm.
2. Ozone less than 51 ppb.

 

A01.4 – Meet radon threshold
If project has regularly occupied space at or below grade, one of the following requirements is met:

1. The radon level is less than 4 pCi/L, as tested by a professional demonstrated not to have a conflict of interest. One test is conducted per 25,000 ft2 of the lowest regularly occupied space at or below grade with natural ventilation.
2. All regularly occupied spaces at or below grade meet the 'Mechanically ventilated spaces' option of Part 1: Ensure Adequate Ventilation in Feature A03: Ventilation Effectiveness.

 

A01.5 – Monitor fundamental air parameters
The following requirements are met:

1. The pollutants listed in this feature, except radon, are monitored at intervals no longer than once per year, and results are annually submitted through WELL Online.
2. The number and location of sampling points for on-going monitoring complies with the requirements outlined in the Performance Verification Guidebook.

 

A02.1 – Prohibit indoor smoking
The following requirement is met:

1. Smoking and the use of e-cigarettes is prohibited in interior spaces within the project boundary.

 

A02.2 – Prohibit outdoor smoking
The following requirements are met:

1. Smoking is prohibited within 25 ft (or the maximum extent allowable by local codes) of all entrances, operable windows and building air intakes. Signage is present to clearly communicate the ban.
2. Smoking is prohibited on all decks, patios, balconies, rooftops and outdoor galleries. Signage is present to clearly communicate the ban.
3. In outdoor areas within the project boundary that allow smoking (if any), signs are placed along walkways (not more than 100 ft between signs) that describe the hazards of smoking.

 

A03.1 – Ensure adequate ventliation
Mechanically ventilated spaces:
Projects utilizing mechanical ventilation comply with ventilation supply and exhaust rates set in one of the following:

1. ASHRAE 62.1-2010 or any more recent versions (Ventilation Rate Procedure or IAQ Procedure).
2. CEN Standards EN 15251:2007 and EN 16798-3:2017 or any more recent versions. The requirements of CEN Standard EN 15251:2007 must be met as well as the performance requirements of CEN Standard EN 16798-3:2017 related to ventilation and room conditioning systems (excluding sections 7.3, 7.6, A.16 and A.17). Note that projects must meet Category I or II as described in the standards.
3. AS 1668.2-2012 or any more recent version. Note that projects that wish to comply with AS 1668.2 must assume a minimum density of 170 ft2 per person.
4. CIBSE Guide A: Environmental Design, version 2007 or any more recent version.

 

A03.2 – Conduct system balancing
To verify compliance with the ventilation rate requirements specified in Part 1: Ensure Adequate Ventilation, the following requirements are met or are scheduled to be met (as applicable):

1. Newly installed mechanical ventilation system or ventilation system that undergoes significant alterations is tested and balanced in accordance with ASHRAE 111.
2. Existing mechanical ventilation system is tested and balanced every five years to verify that the minimum ventilation rates (as determined in Part 1: Ensure Adequate Ventilation) are within ± 10% of the minimum design values.
3. Projects using the elevated air speed method for thermal comfort verify that air speed complies with design specifications.

 

A04.1 – Mitigate construction pollution
For construction occuring after project registration, at least three of the following requirements are met:

1. Projects meet one of the below:
   1. Ducts are sealed and protected from possible contamination during construction.
   2. Ducts are cleaned prior to installing registers, grills and diffusers.
2. If permanently installed ventilation system is operating during construction, projects meet the below:
   1. Media filters with a minimum efficiency reporting value (MERV) of 8 are used to filter return air.
   2. All filters are replaced prior to occupancy.
3. The below moisture and dust management procedures are followed:
   1. Carpets, acoustical ceiling panels, fabric wall coverings, insulation, upholstery and furnishings and other absorptive materials are stored in a separate designated area protected from moisture damage.
   2. All active areas of work are isolated from other spaces by sealed doorways or windows or through the use of temporary barriers.
   3. Walk-off mats are used at entryways to reduce the transfer of dirt and pollutants.
   4. Saws and other tools use dust guards or collectors to capture generated dust.
4. To reduce particulate matter emissions from both on-road and non-road diesel fueled vehicles (excluding delivery vehicles) and construction equipment, the below are met:
   1. All non-road diesel engine vehicles comply with the U.S. EPA Tier 4 PM emissions standards or local equivalent when applicable. Engines may be retrofitted with verified technology (required to be U.S. EPA or California Air Resources Board approved) at the time the equipment is first placed on the job site.
   2. All on-road diesel engine vehicles meet the requirements set forth in the U.S. EPA model year 2007 on-road standards for PM or local equivalent when applicable. Engines may be retrofitted with verified technology (required to be U.S. EPA or California Air Resources Board approved) at the time the equipment is first placed on the job site.
   3. All equipment, vehicles and loading/unloading zones are located at least 25 ft away from air intakes and operable openings of adjacent buildings when possible.
   4. All equipment, vehicles and loading/unloading zones are located at least 25 ft away from air intakes and operable openings of adjacent buildings when possible.
5. Upon completion of construction (including installation of woodwork, doors, acoustic tiles, paints, carpets, movable furnishings and other interior finishes), a building air flush is performed while maintaining an indoor temperature of at least 59 °F and relative humidity below 60%, at one of the below volumes:
   1. A total air volume of 14,000 ft³ of outdoor air per ft² of floor area prior to occupancy.
   2. A total air volume of 3,500 ft³ of outdoor air per ft² of floor area prior to occupancy, followed by a second flush of 10,500 ft³ of outdoor air per ft² of floor area post-occupancy. While the post-occupancy flush is taking place, the ventilation system must provide at least 0.3 m³ per minute of outdoor air per ft² of floor area at all times.

 

A05.1 – Meet enhanced thresholds for particulate matter
The following requirement is met:

1. Projects comply with the thresholds specified in the table below:

Particulate Matter Thresholds	Points
PM2.5 < 12 μg/m³. PM10 < 30 μg/m³.	1
PM2.5 < 10 μg/m³. PM10 < 20 μg/m³.	2

 

A05.2 – Meet enhanced thresholds for organic gases
The following thresholds are met:

1. Formaldehyde less than 13.4 ppb.
2. Benzene less than 3 μg/m³.

 

A05.3 – Meet enhanced thresholds for inorganic gases
The following thresholds are met:

1. Carbon monoxide less than 6 ppm.
2. Ozone less than 25 ppb.
3. Nitrogen dioxide less than 21 ppb.

 

A06.1 – Increase outdoor air supply
The following requirement is met

1. Projects exceed outdoor air supply rates described in ASHRAE 62.1-2010 by the percentages shown in the table below:

Thresholds	Points
30%	1
60%	2

 

A06.2 – Implement demand-controlled ventilation
All regularly occupied spaces meet the following requirements:

Thresholds	Points
900 ppm	1
750 ppm	2
600 ppm	3

1. A demand-controlled ventilation system regulates the outdoor ventilation rate to keep CO2 levels at maximum intended occupancy less than the thresholds specified in the table below:
2. Carbon dioxide is measured at the air exhaust diffusers or in occupied space at 1.1-1.7 m [3.6-5.6 ft] above the floor (away from doors, windows, air supply and zones where occupants may exhale directly into the sensor). At least one sensor is used for each major occupancy zone (or per air handling unit if a single zone is served by multiple air handling units). If occupancy density/pattern/usage is different in two adjacent areas, each area must be considered a separate zone.

 

A06.3 – Implement displacement ventilation
Projects implement a displacement ventilation system for heating and/or cooling, wiht one of the following as a basis for design:

1. ASHRAE Guidelines RP-949.
2. REHVA Guidebook No. 01 (Displacement Ventilation in non-industrial premises).
3. ASHRAE's UFAD Guide: Design, Construction and Operations of Underfloor Air Distribution Systems. Air supply temperature is slightly cooler or warmer than the desired space temperature. Air distribution system is installed at a raised floor height whereby the underfloor area can be cleaned on an annual basis.

 

A06.4 – Implement advanced air distribution
At all workstations, the following requirements are met:

1. Conditioned air is supplied via an individual diffuser that is positioned no further than 2.6 ft from an occupant's head.
2. Occupants are given control over the direction of the supplied airflow and supply air speed (within 0.0-3.9 ft/s in the head region).
3. Supplied air uses one of the strategies specified in the table below:

Requirement	Points
Background mechanical system is used for ventilation	2
Dedicated outdoor air system is used for ventilation	3

 

A07.1 – Provide operable windows
The following requirements are met:

1. Project meets one of the below:
   1. At least 75% of regularly occupied spaces have operable windows that proide access to outdoor air.
   2. The openable window area is equivalent to at least 4% of the net occupiable floor area of that space or floor plate.
2. Project does not use radiant cooling systems if situated in climates with an annual relative humidity above 70%.

 

A07.2 – Manage window use
Outdoor air measurement
The following requirements are met:

1. Outdoor levels of ozone, PM2.5 or PM10, and temperature are monitored at intervals of at least once per hour based on a data-gathering station located within 2.5 mi of the building.
2. Data collected are made available to building occupants.

Window operation
Indicator lights at windows and/or online notifications signal to regular building occupants when outdoor air allows for open windows based on when the following thresholds are met:

1. PM2.5 less than 15 μg/m³.
2. PM10 less than 50 μg/m³.
3. Dry-bulb temperature within 15 °F of indoor air temperature setpoint.
4. Ozone less than 51 ppb.

 

A07.3 – Apply universal design to windows
All operable windows in regularly occupied spaces comply with the following requirements:

1. Provide enough space to permit occupants to approach and operate them (from both a standing and seated position).
2. Are operable with one hand and with a closed fist and do not require tight grasping, pinching or twisting of the wrist.
3. Require less than 5 lbs of force to open.

 

A08.1 – Implement indoor air monitors
The following requirements are met:

1. Monitors measure at least three of the following within a regularly occupied or common space in the building:
   1. PM2.5 or PM10 (accuracy 5 μg/m³ + 15% of reading at values between 0 and 50 μg/m³).
   2. Carbon dioxide (accuracy 50 ppm + 3% of reading at values between 400 and 2000 ppm).
   3. Carbon monoxide (accuracy 1 ppm at values between 0 and 10 ppm).
   4. Ozone (accuracy 10 ppb at values between 0 and 100 ppb).
   5. Nitrogen dioxide (accuracy 20 ppb at values between 0 and 100 ppb).
   6. Total VOCs (accuracy 20 μg/m³ + 20% of reading at values between 150 and 2000 μg/m³).
   7. Formaldehyde (accuracy 20 ppb at values between 0 and 100 ppb).
2. Monitor density is minimum one per floor or one every 3,500 ft2, whichever is more stringent. Monitors are sited at locations compliant with the following requirements:
   1. 3.6-5.6 ft above the finished floor at locations where occupants would typically be seated or standing.
   2. Sampling points must be at least 3.3 ft away from doors, windows and air supply/exhaust outlets.
3. Measurements are taken at intervals of no longer than 10 minutes for particulate matter and carbon dioxide and no longer than one hour for other pollutants.
4. Data are analyzed for regularly occupied hours (e.g., median, mean, 75th, 95th percentile) and submitted annually through WELL Online.
5. Monitors are recalibrated or replaced annually, with documentation attesting to their calibration or replacement submitted annually through WELL Online.

 

A08.2 – Promot air quality awareness
Environmental measures display:
Real-time display of air pollutants measured in Part 1: Implement Indoor Air Monitors is made available to occupants through one of the following:

1. At least one display is prominently positioned at a height of 3.6–5.6 ft per 10,000 ft² of regularly occupied space.
2. Required data are hosted on a website or phone application accessible to occupants. At least one visible sign is positioned per 10,000 ft² of regularly occupied space indicating where the data may be accessed.

Air quality education:
At least two of the following requirements are met:

1. A digital or physical library is provided to occupants that includes at least two resources outlining the impact of indoor air quality on human health as part of the resource library required through Feature C01: Health and Wellness Awareness.
2. A labeling system (e.g., colors or symbols) is clearly displayed next to each monitor screen used for air quality monitoring or at the relevant website. Information about health effects is shown in relation to a range of concentrations of air pollutants monitored in Part 1: Implement Indoor Air Monitors. An explanation of the labeling system is provided.
3. Paper or digital communication that highlights the importance of indoor air quality for human health, including practical tips for how to improve indoor air quality, is issued at least every quarter.
4. Educational training led by an air quality expert is held at least once per year and covers aspects of health and wellness covered in the WELL Air concept, including interpretation of data collected and practical tips for how to improve indoor air quality.

 

A09.1 – Design healthy envelope and entryways
Building envelope and entry:
At least two of the following requirements are met:

1. The below is performed after substantial completion of construction and prior to occupancy:
   1. Envelope commissioning in accordance with ASHRAE Guideline 0-2013 and the National Institute of Building Sciences (NIBS) Guideline 3-2012 (for new construction or structural renovation).
   2. The commissioning process is performed by an independent professional who is not a member or subcontractor of the building envelope design and construction team.
2. All regularly used entrances that have pedestrian traffic to the building surroundings (not including balconies or terraces) use an entryway system composed of grilles, grates, slots or rollout mats that are at least the width of the entrance and 10 ft long in the primary direction of travel (sum of indoor and outdoor length). These are cleaned as per below:
   1. Walk-off mats, indoor and outdoor, are wet-cleaned at least once every two days and fully dry before use.
   2. Underside of entry mats are cleaned at least once a day.
   3. Entry mats are vacuumed using a vacuum with a beater bar in both directions at least once a day.
3. At regularly used entrances that have pedestrian traffic to the building surroundings (not including balconies or terraces), one of the below is in place to slow the movement of air from outdoors to indoors:
   1. Building entry vestibule with two typically closed doorways.
   2. Revolving entrance doors.

 

A10.1 – Manage combustion
Appliance and heater combustion ban:
The following requirement is met:

1. Combustion-based fireplaces, stoves, space heaters, ranges and ovens are not used in regularly occupied spaces.

Low-emission combustion sources:
The following equipment used by the project for heating, cooling, water heating, process heating or power generation (including back-up if used for more than 200 hours per year) meet California's South Coast Air Quality Management District rules, or approved equivalent, for pollution:

1. Internal combustion engines.
2. Furances.
3. Boilers, steam generators and process heaters.
4. Water heaters.

Engine exhuast reduction:
The following requirement is met:

1. Vehicle engine idling for more than 30 seconds is prohibited in all pick-up, drop-off and parking areas. "No idling" signage is present at these locations indicating this rule.

 

A11.1 – Manage pollution and exhaust
All bathrooms, kitchens, rooms for cleaning and chemical storage, rooms with high-volume printers and copiers, and high-humidity areas meet one of the following requirements:

1. Are separated from all adjacent regularly occupied spaces with self-closing doors and/or vestibules.
2. Utilize exhaust fans so that return air is expelled outdoors rather than recirculated.

 

A12.1 – Implement particle filtration
The following requirements are met:

Annual Average Outdoor PM2.5 Threshold	Minimum Air Filtration Level
16 μg/m³ or less	MERV 8 or G4
17–18 μg/m³	MERV 10 or M5
19–23 μg/m³	MERV 12 or M6
24–39 μg/m³	MERV 14 or F8
40–59 μg/m³	MERV 16 or E10
60 μg/m³ or greater	MERV 16 preceded by MERV 8, or E10 preceded by G4

1. Media filters are used in the ventilation system to filter outdoor air supplied to occupiable spaces in accordance with thresholds specified in the table below:
2. Filter is equipped with on-board pressure sensors or filter change indicator that signal when filter requires replacement. Evidence that the filter has been replaced according to manufacturer's recommendation is submitted annually through WELL Online.

 

A13.1 – Implement carbon filtration
The following requirements are met:

1. Projects utilize one of the below to remove VOCs from indoor air:
   1. Activated carbon filters or a combination of particulate/carbon filters in the main air ducts to filter recirculated air.
   2. A standalone air-cleaning device that utilizes a carbon filter to treat the air (one device per area coverage as specified by the manufacturer).
2. Evidence that the filter or device has been replaced or maintained according to manufacturer's recommendation is submitted annually through WELL Online.

 

A14.1 – Implement ultraviolet air treatment
The following requirements are met:

1. Project utilizes one of the below:
   1. Projects with a forced-air cooling system use ultraviolet lamps to irradiate the surfaces of the cooling coils and drain pans of the mechanical system supplies.
   2. Projects without a forced-air cooling system use standalone ultraviolet germicidal irradiation air sanitizers in all spaces with more than 10 regular occupants.
2. Evidence that the device has been replaced or maintained according to manufacturer's recommendation is submitted annually through WELL Online.

 

A14.2 – Manage condensation and mold
Condensation management:
Condensation management is addressed within the project and considers the following:

1. High interior relative humidity levels, particularly in susceptible areas like laundry rooms, below-grade spaces and other high-humidity areas.
2. Air leakage that could wet either exposed interior materials or interstitially hidden materials.
3. Cold surfaces such as basements, slab-on-grade floors or the inside of exterior walls.
4. Oversized air conditioning units.

Mold inspections:
The following requirements are met:

1. Annual inspections for signs of water damage or pooling, discoloration and mold on ceilings, walls and floors is performed by a professional demonstrated not to have a conflict of interest. The report is submitted annually through WELL Online.
2. One of the below is met:
   1. Project achieves cooling coil mold reduction as per Part 1: Implement Ultraviolet Air Treatment.
   2. All cooling coils (where applicable) are inspected on a quarterly basis for mold growth and cleaned if necessary. Dated photos demonstrating adherence are submitted annually through WELL Online.
3. c. For projects with tenants, there is a system in place for notifying building management about mold or water damage and addressing concerns.

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