A12: Air Filtration

(1 point)

INTENT

Remove indoor and outdoor airborne contaminants through air filtration.

SUMMARY

This WELL feature requires projects with mechanically ventilated spaces to implement adequate air filtration and document a maintenance protocol for installed filters. For naturally ventilated spaces, this feature requires that outdoor air quality standards be met.

ISSUE

Exposure to particulate matter (PM) is associated with a host of negative health outcomes. PM₁₀ can block and inflame airways, causing a range of respiratory-related conditions that can lead to illness or death. PM_2.5 poses even greater health risks compared to PM₁₀ because it can penetrate deep into the lungs, enter the bloodstream and as a result, cause a variety of health issues including heart disease and other cardiovascular complications.

SOLUTIONS

Selection and installation of adequate media filters is one of the key mechanisms for minimizing exposure to outdoor and indoor air pollution. Studies have shown that decreased exposure to particulate matter by filtration of recirculated indoor air is associated with reduced risk of cardiovascular disease and is an effective control measure for reducing allergic respiratory disease. In addition, regular filter maintenance is critical to ensure proper air filtration and the efficiency of the air conditioning system. During the operation, filters should be replaced when they become loaded with particles, as they will begin to reduce airflow and increase pressure drop. Overloaded filters not only restrict airflow rate but can also result in a loss of filtration efficiency. Improper operation or maintenance of filtration systems has been associated with symptoms such as dry eyes, skin and throat irritation, fatigue and headache and can lead to more severe implications such as Legionnaires' disease. Additionally, it is critical for projects to be aware if their building is located in an area with elevated outdoor air pollution, as these projects often need to install a pre-filtration stage in addition to the primary filtration to maintain high quality indoor air.

IMPACT

Proper air filtration and the execution of a maintenance protocol over the life of a filter help to improve and maintain indoor air quality over time and play a fundamental role in creating healthier buildings.

REQUIREMENTS

Part 1

Implement Particle Filtration (1 point)

Verified by MEP, On-going Maintenance Report, Photographic evidence

For All Spaces

Mechanically and Mixed-mode ventilated spaces:

The following requirements are met:

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:

   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

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.

 

Note: The World Health Organization’s Global Urban Ambient Air Pollution Database may be consulted to view outdoor air quality levels, available at http://www.who.int/airpollution/data/cities/en/

© International WELL Building Institute