Breathe Easy: ASHRAE’s Guidelines for Better Indoor Air

Ever wonder what makes the air inside buildings healthy to breathe? ASHRAE publishes standards and guidelines for indoor air quality. Here’s what you need to know in plain language. 

What Are These Guidelines? 

Think of ASHRAE Standard 62.1-2022 as a rulebook for good indoor air in commercial facilities. It sets minimum requirements for ventilation (bringing fresh air in) and other measures to keep indoor air healthy for people. The goal is simple: make sure the air we breathe indoors won’t make us sick. 

Who Do These Guidelines Affect? 

These guidelines apply to most buildings where people spend time, except for residential homes. They’re used when: 

• Building new structures 
• Adding to existing buildings 
• Making certain changes to buildings 
• Improving air quality in older buildings 

Better Indoor Air: The Main Points Made Simple

Fresh Air Systems 

The guidelines explain how to design, install, and maintain systems that bring fresh air inside and clean the air that’s already there. 

Indoor Air Pollutants 

The rules address things that can make indoor air unhealthy, including: 

• Outdoor pollution coming inside 
• Dust and chemicals from construction 
• Moisture and mold 
• Cigarette smoke 

Outdoor Air Quality 

Before designing a ventilation system, builders need to check if the outdoor air in the area is clean enough. If it’s not, they must add filters or air cleaners to remove particles and harmful gases. 

Equipment Requirements 

The guidelines have specific rules for air system parts like: 

• Where outdoor air enters the building (keeping these intakes away from exhaust fans, garbage areas, and other sources of pollution) 
• Surfaces that the air flows over (making sure they resist mold) 
• Drain pans (ensuring they don’t become breeding grounds for bacteria) 
• Humidifiers (devices that add moisture to the air) 

There’s also emphasis on preventing Legionnaires’ disease, a serious type of pneumonia that can spread through water systems. 

Air Classification 

Not all indoor air is equal. The guidelines sort air into four classes based on how contaminated it might be and set rules for when this air can be reused or moved to other areas. 

Determining How Much Fresh Air Is Needed 

Designers can use several methods to figure this out: 

• A straightforward approach based on room type and size 
• A more complex method analyzing specific pollutants 
• Guidelines for systems using natural airflow (like windows) 

Keeping It Clean 

The rules emphasize keeping air ducts clean during construction and making sure fresh air dampers (valves that control airflow) work properly before people move in. 

Ongoing Maintenance 

Regular upkeep of ventilation systems is required to ensure they continue working effectively. 

Checking Results 

For projects using the more complex design method, testing is required after completion to verify the air is actually clean. 

ASHRAE: Your Resource for Better Indoor Air 

These guidelines are constantly being updated as new research emerges. While following them isn’t legally required (unless local building codes say so), they’re widely recognized as the gold standard for healthy indoor air. By understanding these basics, you can better appreciate the behind-the-scenes work that goes into making the air in your workplace, school, or public buildings safe to breathe. To fully understand the standard, you can access a readable version of the entire document by visiting ASHRAE’s Technical Resources.