Indoor air quality (IAQ) is one of the most critical, yet often overlooked, factors influencing comfort, productivity, and long-term health in commercial and industrial spaces. According to the EPA, concentrations of some pollutants are 2–5 times higher indoors than outdoors, and studies show people spend up to 90% of their time inside buildings. That means the quality of the air your employees breathe directly affects their well-being and performance.

This article explores why IAQ matters, what causes poor air quality in industrial facilities, and how to improve it.

Why Indoor Air Quality (IAQ) Matters

Poor indoor air quality affects more than comfort; it impacts people and profits. The U.S. Environmental Protection Agency estimates that poor air quality costs businesses tens of billions of dollars each year through increased medical expenses, absenteeism, and reduced productivity.

Employees working in environments with stale or contaminated air often experience fatigue, headaches, and respiratory irritation that can lead to missed workdays or turnover. Conversely, facilities that prioritize IAQ see measurable benefits: fewer complaints, better retention, and higher throughput and quality.

How to Measure IAQ

In commercial and industrial buildings, “acceptable IAQ” and minimum outdoor-air (OA) rates are defined by ASHRAE 62.1. Designers should select either the Ventilation Rate Procedure (VRP), IAQ Procedure (IAQP), Natural Ventilation Procedure or a combination thereof. The more common VRP should be used when a prescriptive, table-based approach is sufficient, and contaminants are well characterized. The final required zone and system OA flows are determined by occupancy category, per-person and per-area OA components, occupant density, and system ventilation efficiency – all of which should be documented.

The IAQ Procedure (IAQP) is a more engineered path in ASHRAE 62.1 used to determine design OA rates that limit concentrations of design compounds and PM2.5 to indoor design limits based on the indoor and outdoor sources, air cleaning and other variables. The design OA rate must be calculated with mass-balance equations and occupant satisfaction and indoor design compound concentrations must be verified after the building is complete (ASHRAE 62.1, 6.1.2.). This procedure can potentially reduce required OA ventilation rates when justified. 

The Natural Ventilation Procedure (NVP) follows a prescriptive compliance path or an engineered system compliance path per section 6.4 in ASHRAE Standard 62.1-2022. The NVP allows designers to meet ventilation requirements with outdoor air delivered through operable openings, windows, vents, and shafts, when those openings are carefully sized, located, and controlled per ASHRAE requirements. In practice, that means verifying outdoor air quality, providing controls that keep openings available during occupancy, and treating those openings like outdoor-air intakes with required separation from exhausts and other contaminant sources. Most projects still need a mechanical backup unless they meet strict NVP conditions during all occupied hours.

In addition to OA delivery, ASHRAE 62.1 requires that mechanical cooling systems and indirect evaporative cooling systems are designed to limit the indoor air dew point a maximum of 60F, primarily to reduce the risk of microbial growth. The standard also calls out minimum separation distances between OA intakes and contamination sources which influences coil sizing and economizer logic. 

Meeting ASHRAE 62.1 requirements is more than a code checkbox. Good indoor air quality reduces complaints of odor and stale air and allows occupants to work more productively in a healthier environment.

What Causes Bad IAQ in Commercial and Industrial Facilities

Indoor air problems can stem from many sources, both environmental and operational.

• Process Contaminants: Welding fumes, vehicle exhaust, sawdust, textile fibers, and VOCs from coatings or solvents can all degrade indoor air quality. Localized exhaust and process capture should be the first defense against these pollutants.
• Insufficient Ventilation: Facilities that rely heavily on recirculation often allow CO₂ and particulates to accumulate, even when temperatures feel comfortable. Ensuring sufficient outdoor air per ASHRAE 62.1 standards helps maintain proper dilution and balance.
• Moisture and Humidity: Sustained relative humidity (RH) above 60% fosters mold growth, microbial contamination, and allergen proliferation. Leaks, washdowns, and infiltration should be addressed promptly to prevent these issues.
• Combustion Safety: Poorly vented combustion equipment can introduce carbon monoxide (CO) into occupied areas. Regular maintenance, CO monitoring, and proper ventilation are critical safeguards.

For a deeper look at pollutants and contaminants that affect air quality, visit our related article: Common Indoor Air Pollutants in Industrial Facilities.

How to Improve Indoor Air Quality

Improving IAQ involves a combination of source control, ventilation, filtration, and humidity management, all supported by energy-aware system design.

Cambridge equipment is purpose built to deliver 100% outside air to provide ventilation air, maintain positive or neutral building pressure, improve IAQ, and deliver season-to-season comfort through energy efficient HTHV heating technologies and direct, indirect, or combination indirect/direct evaporative cooling solutions. This approach eliminates recirculation and improves dilution of indoor pollutants which are often 2–5× higher indoors.

1. Source Control

The most effective way to improve IAQ is to eliminate or reduce pollutants at their source. Local exhaust or process capture systems intercept contaminants as they’re generated, preventing them from dispersing throughout the workspace. Using low-VOC materials, enclosing high-heat or moisture-generating processes, and maintaining combustion systems all reduce the IAQ load.

In complex facilities, a building consultation may be necessary to properly balance fresh-air strategies with source control, ensuring ventilation complements, not counteracts, your process needs.

2. Ventilation with Clean Outdoor Air

Proper ventilation dilutes contaminants, controls CO₂ and odors, and supports both comfort and safety. Verifying outdoor air rates and balancing supply and exhaust systems is essential for compliance and performance.

Cambridge Air Solutions provides systems designed specifically for this challenge:

• M-Series Make-Up Air Units deliver 100% outdoor air to replace exhausted air, maintaining neutral or positive pressure and comfort across seasons.
• S-Series and SA-Series Heating and Ventilation Units use 100% fresh air to destratify heated air in large spaces while maintaining clean, healthy air circulation.
• Each series includes high-efficiency filtration options (up to MERV-13) and optional DX or chilled-water cooling coils to temper outside air.

These systems not only meet ASHRAE requirements but also support energy-efficient operation and long-term reliability.

3. Filtration and Air Cleaning

Filtration removes particulates and odors, complementing ventilation and source control. The right MERV-rated filters should match the facility’s process risk, balancing particle removal with fan performance.

For heavy-load areas such as welding, grinding, or machining, local capture and hood systems should be prioritized over reliance on recirculated air. When specifying make-up air or evaporative cooling systems, always include integral filter racks for easy maintenance and consistent filtration of incoming outdoor air.

4. Humidity and Moisture Management

Maintaining indoor RH between 30–50% not only improves comfort but prevents microbial growth and allergen issues. Washdown zones and wet processes require targeted ventilation strategies to avoid over-saturation. Preventive maintenance, which includes repairing leaks, monitoring RH, and ensuring proper air movement, helps sustain both building health and occupant wellbeing.

5. Energy-Aware Cooling

Cooling is often the largest electric load in a facility that relies on mechanical cooling systems. Intentional ventilation strategies, efficient ductwork design, right-sized high efficiency equipment and smart building controls can reduce energy use and reduce equipment wear and tear.

Alternative technologies can offer significant energy savings in the right applications. Evaporative cooling eliminates the need for compressors, massively reducing energy use while bringing in large volumes of tempered outdoor air for ventilation. Direct evaporative cooling (DEC) technologies can achieve up to 90% cooling effectiveness by reducing the dry-bulb temperature of incoming air by up to 90% of the difference between its dry-bulb and wet-bulb temperatures. Since DEC performance depends on web-bulb depression, it performs best in dry to semi arid climates or during shoulder seasons in more humid climate zones. 

The Cambridge E-series and ESC-series evaporative coolers can achieve up to 70% energy savings compared to mechanical cooling systems while improving air quality and comfort due to their ability to provide up to 100% outside air. 

These solutions improve indoor comfort, reduce operational costs, and maintain proper ventilation, particularly in facilities with heavy exhaust demands or those located in dry and semi-arid climates.

Measuring the ROI That Better IAQ Delivers

Health and Productivity

Cleaner indoor air leads to fewer complaints, fewer sick days, and higher productivity. Workers in environments with good air quality report improved focus and comfort, reducing absenteeism and boosting output.

Comfort and Retention

When employees feel comfortable and healthy at work, retention rates improve. A well-ventilated facility reinforces a culture of safety and care, which strengthens morale and engagement.

Energy and Maintenance

Intelligently designed HVAC strategies, including HTHV heating and evaporative cooling, can reduce total HVAC energy use by 40–70%, simplify maintenance, and eliminate components that commonly fail in traditional systems.

Our equipment combines efficiency and simplicity: HTHV units use 100% outside air to destratify and heat efficiently, while evaporative systems deliver cost-effective cooling and ventilation for large industrial spaces.

Enhance Your Facility’s Indoor Air Quality with Cambridge Air Solutions

Better indoor air quality supports productivity, retention, safety, and energy efficiency, all while creating a more comfortable environment for every person in your facility.

We design and manufacture ventilation, heating, and cooling systems built for large commercial and industrial spaces, helping companies achieve better IAQ and long-term operational success.

Explore our complete line of industrial air solutions at Cambridge Air Solutions Industrial Markets, or contact us to discuss how we can help you meet your IAQ needs. No matter how unique or standard, our experts will strategize a solution that’s right for you. 

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