This is a legacy version of the WELL Building Standard. Please check the latest version here.

Ventilation effectiveness

Ventilation effectiveness

Intent: 

To ensure adequate ventilation and high indoor air quality.

BACKGROUND

Routine indoor activities including cooking, cleaning, building operations and maintenance and even the presence of occupants themselves can degrade air quality. Many indoor pollutants resulting from such activities, including particulate matter and VOCs can cause discomfort and trigger asthma and eye, nose and throat irritation. Because it is difficult to test for every potential pollutant, and because carbon dioxide is easy to detect, carbon dioxide levels serve as a proxy for other indoor pollutants.

Part 1
Ventilation Design

One of the following requirements is met for all spaces:
a.6
Ventilation rates comply with all requirements set in ASHRAE 62.1-2013 (Ventilation Rate Procedure or IAQ Procedure).
b.6
Projects comply with all requirements set in any procedure in ASHRAE 62.1-2013 (including the Natural Ventilation Procedure) and demonstrate that ambient air quality within 1.6 km [1 mi] of the building is compliant with either the U.S. EPA's NAAQS or passes the Air Quality Standards feature in the WELL Building Standard for at least 95% of all hours in the previous year.

Part 2
Demand Controlled Ventilation

For all spaces 46.5 m² [500 ft²] or larger with an actual or expected occupant density greater than 25 people per 93 m² [1,000 ft²], one of the following requirements is met:
a.7
A demand controlled ventilation system regulates the ventilation rate of outdoor air to keep carbon dioxide levels in the space below 800 ppm (measured at 1.2-1.8 m [4-6 ft] above the floor).
b.7
Projects that have met the Operable windows feature demonstrate that natural ventilation is sufficient to keep carbon dioxide levels below 800 ppm (measured at 1.2-1.8 m [4-6 ft] above the floor) at maximum intended occupancies.

Part 3
System Balancing

After the HVAC system is installed, the following requirement is met:
a.
After substantial completion and prior to occupancy, the HVAC system has (within the last 5 years), or is scheduled to, undergo testing and balancing.

Part 4
Ventilation Rates for Residences

Depending on ventilation methods, one of the following is met:
a.117
Ventilation rates are designed to comply with all requirements set in ASHRAE 62.2-2013 (Ventilation Rate Procedure or IAQ Procedure) for residential buildings of 3 or fewer floors.
b.6
Ventilation rates are designed to comply with all requirements set in ASHRAE 62.1-2013 (Ventilation Rate Procedure or IAQ Procedure) for residential buildings of more than 3 floors above grade.
c.
Projects comply with all requirements set in the Natural Ventilation Procedure in ASHRAE 62.1-2013 or ASHRAE 62.2-2013 (as appropriate for number of floors above grade) and demonstrate that ambient air quality within 1.6 km [1 mi] of the building is compliant with either the U.S. EPA's NAAQS or passes the Air Quality Standards feature in the WELL Building Standard for at least 95% of all hours in the previous year.