Figure 1.1-A. Traditional Design Team: The IAQ Guide discusses moving away from the traditional hierarchy inherent in most design and construction processes and instead, focusing on communicating and coordinating effectively. Used by permission from ASHRAE.

HVAC professionals interested in making sure commercial facilities have good IAQ now have a resource available to them that offers practical guidance for achieving the best possible indoor environments. That resource is theIndoor Air Quality Guide: Best Practices for Design, Construction, and Commissioning, published by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) in collaboration with the American Institute of Architects, the Building Owners and Managers Association International, U.S. Environmental Protection Agency, the Sheet Metal and Air Conditioning Contractors’ National Association, and the U.S. Green Building Council.

The guide is a comprehensive and practical resource that will help engineers, contractors, architects, building owners, and others achieve better IAQ in commercial and institutional buildings that are covered by American National Standards Institute (ANSI)/ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality. The guide describes 40 strategies for attaining critical IAQ objectives related to moisture management, ventilation, filtration and air cleaning, and source control. It also highlights how design and construction teams can work together to ensure that good IAQ strategies are incorporated from initial design through project completion.

This last point may be the main reason why HVAC contractors should read the guide, said Andrew Persily, Ph.D., chairman, IAQ Guide Steering Committee, as contractors are often the last ones brought in on a building project. “This guide discusses the process of getting IAQ into the early stages of design. Ideally, contractors will learn how to better insert themselves into this process earlier and more effectively, before all the critical decisions have been made.”


When Standard 62.1 was rewritten for code reference and adoption many years ago, some in the industry felt that it needed a companion guide to explain in detail how to achieve proper IAQ in commercial buildings. This guide would go beyond the minimum requirements specified in the standard and would detail the comprehensive treatment of IAQ in buildings. In 2006, discussions on creating this type of guide began in earnest, culminating in the publication of the IAQ Guideearlier this year.

“It took a little more than three years to produce the guide, but the time invested was worth it because it contains the input of IAQ experts, building designers, contractors, researchers, and many others. Collectively, this group has several hundred years of expertise concerning IAQ issues,” said Persily.

The guide is meant primarily for new construction, but many of the topics discussed can also apply to retrofit situations and significant renovations. Persily noted that contractors will benefit from reading the guide, as it will give them a better sense of what it takes to improve IAQ in buildings, whether it is new construction or retrofit. “They’ll learn more about the key issues that cause problems, as well as opportunities to improve IAQ and the strategies that can be used to realize those improvements.”

The guide is organized around eight objectives, with the first one probably being the most important, noted Persily. “The first objective is all about the design and construction process and how everyone needs to get to together to communicate and coordinate effectively. I think that is probably the best place to start because, for a lot of contractors, it reinforces what they already know. In addition, it puts into perspective how IAQ is related to that whole issue of integrated design and better coordination and communication between the professionals involved in the process.”

Figure 1.1-B. Integrated Design Team: IAQ is related to the whole issue of integrated design and better coordination and communication between the professionals involved in the process, and achieving that integration is detailed in the IAQ Guide. Used by permission from ASHRAE.

One very important area that is not covered in the guide is service and maintenance, which can obviously have a direct impact on IAQ. “The guide does not speak to maintenance activities, but it does address how to design a building to facilitate service and maintenance. Providing access to key systems and components is an extremely important design decision because, for example, if you can’t get to the system to change the filters, it is much less likely to happen.”

A future revision of the guide may cover maintenance, or perhaps this will be addressed in a different document, added Persily. “Many of the issues we deal with - IAQ, energy, thermal comfort - are broken up into different standards, but they’re all interrelated. It’s obvious that what is good for operation and maintenance is good for energy and IAQ.”

While the guide has only been available a short time, reaction from the HVAC community has been positive, said Persily. Many have commented that they are glad a comprehensive discussion of IAQ is finally available and that its publication is particularly timely, given the current focus on proving energy efficiency. “In the name of energy efficiency, we don’t want to make buildings less desirable and less comfortable, if not less healthy, so the timing of the guide is really good.”

If contractors like what they see in theIAQ Guide, or they have suggestions for improvements, Persily recommends they visit the ASHRAE website, which provides an area to comment on its content ( “We welcome any and all suggestions, as it will be useful in the future when we look to revise the guide.”

A summary document of theIndoor Air Quality Guidecan be downloaded for free at The full publication complete with a CD that contains detailed guidance essential for practitioners to design and achieve good IAQ is available in hard copy or electronically for $29. To order, contact ASHRAE customer service at 800-527-4723 or 404-636-8400, 404-321-5478 (fax), or visit

Sidebar: Tips From the Guide

ASHRAE’s IAQ Guide contains eight objectives for achieving optimal IAQ in commercial buildings, and some of the suggestions made in the guide are:

• Bring IAQ into the very earliest design discussions. Don’t get stuck retrofitting the design for IAQ at the end of the process.

• Strictly limit liquid water penetration and condensation in the envelope, and control indoor humidity.

• Where outdoor air quality is poor, use enhanced filtration and air cleaning to provide high-quality ventilation air. Locate outdoor air intakes away from contaminant sources and provide the means to measure and control minimum outdoor airflows.

• Select building materials and furnishings that have low contaminant emissions and don’t require use of high-emitting cleaning products.

• Exhaust contaminants from indoor activities as close to their source as possible.

• Recognize that O&M is essential to long-term IAQ, and provide the access, training, and documentation needed to facilitate O&M.

• Commission from design through occupancy to ensure that IAQ objectives are met.

Publication date:11/08/2010