Indoor air quality (IAQ) directly impacts the comfort, health, and safety of your building’s occupants. Poor air quality management can lead to significant short and long-term health risks for occupants, as well as reduced productivity and concentration. Code compliance and legal scenarios also hang in the balance for a wide range of public and private indoor environments, such as educational facilities. Investing in precision air quality testing equipment helps ensure you are prepared. 

What Is Indoor Air Quality (IAQ)?

According to the EPA definition, "Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns."

In other words, IAQ is a description of how the air inside of your building is affecting the occupants' health, comfort, or ability to work.

Why is Indoor Air Quality Important?

Good IAQ is important for the health and safety of all occupants in your building. From a legal standpoint, compliance with all work environment regulations for IAQ will be essential to operating a safe and successful business. Business owners and building managers alike also understand the value of a comfortable environment. Attention to your air quality can support higher levels of productivity and employee (or resident) satisfaction. Healthy air and a well-managed indoor climate protects occupants from mold or other indoor air quality pollutants at the same time that it bolsters motivation, mood, wakefulness during the day, and restful sleep at night.

How to Improve Indoor Air Quality

Indoor air quality improvements are possible with the right combination of smart HVAC management and additional indoor air quality solutions. For example, full-time air quality monitors placed in all occupied areas and other climate-sensitive environments (chemical storage, library archives, museum displays, animal habitats, etc.) will help you keep a close eye on IAQ metrics. The right indoor air quality sensors can track all of the necessary variables from temperature and RH to airflow measurement and the presence of harmful but odorless contaminants like CO₂ or irritating  VOCs.

Warnings from your sensors can alert you to take action or even automatically trigger your HVAC system to ensure a healthier, more productive environment. An indoor air quality sensor is not only about in-the-moment solutions, though. These sensors can gather data for insights into long-term trends. Armed with a continuous data model of your building’s IAQ, you can make informed decisions that will optimize your BAS for efficiency and your HVAC schedule for maximum occupant comfort.

Continuous IAQ testing will also give you critical insights into the health and maintenance needs of your building’s HVAC systems. Smart indoor air quality products not only alert you to substandard environments, but provide helpful feedback about the condition or effectiveness of the systems that are regulating it. The more data you have, the easier it will be to maintain compliance and comfort while saving time and money through preventative action.

We'll examine these solutions in more depth in the sections below. 

Table of Contents:

• The Causes of Poor Indoor Air Quality
• Top Air Quality Pollutants
• Indoor Air Quality Management
• Indoor Air Quality Sensors
• CO2 Sensors
• Temperature Sensors
• Humidity Sensors
• Indoor Air Quality Sensor Platform Interfaces
• Find the Right Indoor Air Quality Solution With Veris

The Causes of Poor Indoor Air Quality

According to OSHA, the most common causes of subpar IAQ include:

• Inadequate ventilation
• Poor HVAC maintenance and upkeep
• Dampness and moisture damage (from leaks, flooding, or high humidity climates)
• Contaminated air (indoor or outdoor)

Of further concern is the fact that many indoor air pollutants have no smell.  It’s easy for substances like CO₂ or irritating VOCs to develop undetected until occupants experience symptoms like headaches, fatigue, sleepiness, or other respiratory issues. If these side-effects have begun to appear, you may have a problem with IAQ.

Other factors can also play a role in the way your occupants feel about indoor air quality standards. For example, things like odors, inconsistent temperature, air pressure (drafts or stuffiness), added heat from unfiltered sunlight, and more can affect the comfort of the indoor environment and require remediation from air quality management systems.

Top Air Quality Pollutants

Temperature and relative humidity are important to indoor comfort, but these factors are much easier to notice than many of the air pollutants that can threaten our health. According to the EPA, the 13 indoor air quality pollutants below are the most common threats. All of them fall into the categories of VOCs, biological pollutants, combustion byproducts, and legacy pollutants. Detection of these threats is important to keeping your occupants safe.

• Asbestos: This mineral fiber used to be a common material for roofing shingles, insulation, and fire retardants. Older structures must monitor for asbestos. Exposure can lead to lung disease and other health conditions.
• Biological Pollutants: Bacteria, viruses, pet dander/saliva, dust, mites, mildew, mold, and pollen are all biological pollutants; they're produced by living things. Watch out in areas with excessive moisture or unvented bathrooms.
• Carbon Monoxide: This odorless gas comes from the burning of fossil fuels. Gas heaters or vehicles in garages can create CO buildups if the area is enclosed or poorly ventilated.
• Smoke and Fumes: Smoke and fumes from solid fuels like wood or charcoal, combined with poor ventilation, can cause significant health and lung issues over time.
• Formaldehyde: Common as an ingredient in wood resins, insulation, glues, paints, cosmetics, and pesticides, formaldehyde can also become a combustion byproduct. Fuel-burning appliances may release it into the air, increasing the risk of skin, eye, and respiratory irritation or even cancer.
• Lead (Pb): The most common ways for lead to get into the air are through metal processing and the burning of lead fuel. If inhaled, lead buildups in the body can cause numerous serious health issues.
• Nitrogen Dioxide (NO₂): Burned fuel from vehicles or at power plants can emit NO2 into the air. It's very harmful to individuals with existing respiratory conditions like asthma, and can cause coughing, wheezing, and difficulty breathing.
• Pesticides: Pesticides may help to control insects and other pests, but they're also dangerous to humans when inhaled and can lead to irritation, cancer, or damage to the central nervous system.
• Radon (Rn): This naturally occurring, invisible, odorless radioactive gas can build up indoors after it enters through cracks and holes in the building's exterior or foundation. It's the second leading cause of lung cancer in the U.S. Monitor below-ground floors, basements, and other low, enclosed spaces carefully.
• Indoor Particulate Matter: Some particles in the air, like dust, dirt, sand, and smoke are large enough to be seen. Others are so small that they cannot. These are a larger risk in areas like construction sites, workshops, or the beach.
• Secondhand Smoke/Environmental Tobacco Smoke: Tobacco smoke is a carcinogen that can cause heart disease, stroke, lung cancer, and other serious conditions. Ventilation is essential in any structures in which smoking products like cigarettes and cigars are permitted.
• Volatile Organic Compounds (VOCs): VOCs are emitted from many common chemical products like paints, wood stains or sealers, aerosol sprays, glues, cleaning products, air fresheners, stored fuels, and more. Off-gassing from a fresh coat of paint or shellac can quickly build up VOCs in the air.
• Wood Smoke: Change out old wood stoves with newer and cleaner heating technologies to reduce health risks from the particulate matter in smoke (as mentioned above).

Indoor Air Quality Management

Properly maintained and updated ventilation, heating, and cooling systems are important. However, they’re only as useful as your ability to manage setpoints, automate a schedule, track performance, predict needs, and respond to deficiencies.

The best approach to measuring indoor air quality is to deploy an integrated network of indoor air quality sensors with a combination of RH, temperature, and VOC outputs in all sensitive locations. Comprehensive data from numerous indoor air quality monitor devices will help maintain a reliable environment. A safe, compliant, and comfortable indoor climate ensures that your building and its occupants will thrive.

Among other things, air quality sensors are used to:

• Assess the extent of air pollution in your building
• Evaluate HVAC system performance
• Enable proactive and preventative maintenance
• Provide air quality data in a timely manner
• Better implement and support broader IAQ goals
• Maintain compliance with indoor air quality standards
• Track trends in air quality over time

With modern IAQ sensors, it’s even possible to remotely monitor indoor air quality and adjust fan, thermostat, or ventilation schedules from any location. A remote-enabled sensor system, such as the IAQ sensors made by Veris, makes your job easier and more efficient.  You’ll be able to save on costs, prevent waste, minimize downtime, and meet compliance standards with a simple and highly compatible indoor air quality sensor system.

Indoor Air Quality Sensors

There are many types of indoor air quality sensors available to choose from, according to the specific threats or environmental traits you want to monitor. Here are four of the most common:

• CO2 Sensors:  Occupied but poorly ventilated areas can build up high levels of CO2 due to the breathing of the occupants over time. Use CO2 sensors to alert you when more ventilation is needed to keep the air fresh and CO2 levels low.

• Temperature Sensors: A thermometer or thermostat is a temperature sensor. It generally measures air temperature in either Fahrenheit or Celsius (or both). Temperature sensors can be linked to building automation systems to trigger heating, cooling, and ventilation in response to temperature levels.

• Humidity Sensors: Humidity sensors measure the presence of water in the air. Sometimes high level of humidity are mistaken for heat. Humid air can feel clammy or sticky, increasing the discomfort and sense that the room is too hot, like a humid summer day.  Absolute humidity is a measure of the total water vapor in the air. Relative humidity (RH) is a measure of water vapor as a percentage of the maximum that the air could hold at its current temperature. RH is more important in how we feel temperature.

• VOC Sensors: These sensors detect harmful particulates and volatile compounds in the air that are not easy to detect with our natural senses. A VOC sensor (or another sensor with VOC detection capabilities built in) is an important line of defense for IAQ.

CO₂ Sensors

Whereas temperature and humidity are easy to feel, gas emissions are difficult to detect—and can cause discomfort . It’s important to monitor the concentration of airborne pollutants with a carbon dioxide sensor, preferably with the ability to detect volatile organic compounds (VOCs), carbon monoxide, and nitrogen oxide as well.  Here are a few priorities to set when evaluating CO2 wall mount sensors, duct CO2 sensors, and more:

• Modular: Look for a modular platform of CO₂ sensors. This will eliminate extra costs by giving you the ability to mix and match, switch out, or replace individual air quality sensors at any time.
• Scalable: This helps you maximize your budget. With a flexible design, a CO₂ sensor module allows you to match its measurement and accuracy to the ideal price point for your project.
• Precise: Ideal CO₂ monitors will have impressive measurement resolutions across multiple indicators. Our CW2 series air quality sensors at Veris, for example, detect as little as 1 ppm for CO₂ or a scale of 0 to 1,000 ppb for total VOC (TVOC).
• Versatile: An IAQ sensor is at its best when it has not only a CO2 sensor module, but indicators for VOC, RH, temperature, and more all in the same compact sensor package.

An innovative  CO sensor, NO2 sensor, CO/NO2 sensor or Refrigerant Sensor will drastically reduce project costs for critical environments like parking garages, sally ports, and similar structures. The remote CO₂ sensors from Veris offer several important advantages. You’ll be able to tell instantly, from a distance, if you need to:

• Address low, high, and sensor end-of-life signals
• Hot swap the removable sensor element (to prevent future maintenance costs)
• Adjust the application on the fly with field-selectable output & setpoints

At the same time, Veris sensors give you incredible flexibility and compatibility with removable terminal blocks and the ability to integrate into a variety of control systems (4-20mA, 0-5V, or 0-10V, BACnet MSTP and Modbus RTU). Take a closer look at these leading carbon dioxide and VOC sensors in our CW2 series of CO2 and VOC sensors:

• CW2LA2AV
• CW2LP2AV

Temperature Sensors

Temperature sensors are critical to monitoring the comfort of living and working spaces, but also for protecting temperature-sensitive materials or environments from mishaps. Many indoor temperature sensors focus on air temperature, but this is only one aspect of ensuring a compliant, safe, and comfortable environment.  Pipe temperature sensors, for instance, help to ensure safe and optimal water temperatures (and to predict maintenance issues with heating systems) . 

Here are a few priorities to set when evaluating wall mount temperature sensors, duct temperature sensors, discharge air temperature sensors, and other HVAC temperature sensors:

• Compatible: The more compatible and interchangeable the temperature sensors, the better, so that the output is never an issue for your BAS controller. The Veris TW2 series, for example, allows your choice of 4 to 20mA, 0 to 5Vdc or 0 to 10Vdc outputs.

• Calibration Free: If no calibration is required, you can have the confidence that your indoor temperature sensors are ready and accurate out of the box.

• Easy to Install & Use: The best temperature sensors simplify installation and service with large wiring terminals on the baseplate, snap-on covers, and user-friendly interface (we offer your choice of touchscreen, LCD, or a faceless sensor controlled only via the BAS).

Veris makes temperature sensors for your every need, including: wall, duct, outdoor, averaging, pipe/immersion, discharge air, contact/strap-on, button, ceiling, and more. With the advantages offered by our indoor temperature sensors, you’ll be able to:

• Cut down on time in the field and stock fewer devices with a flexible, configurable design
• Use your existing BAS controller and preferred protocol (BACnet, MSTP, Modbus RTU, etc.)
• Save money with a scalable design that fits your budget while optimizing HVAC efficiency

With the help of temperature sensing devices, climate-dependent locations like museums, schools, printing shops, hospitals, data centers, and others can protect sensitive materials and stay ASHRAE compliant while also ensuring maximum occupant comfort. The best results will come from averaging temperature sensors over time in a continuous, multi-sensor system that models long-term trends and predicts future needs. Take a closer look at these leading wall temperature sensors in our TW2 series of temperature sensors:

• TW2LAXC
• TW2LAXA

Few indoor air quality sensor platforms can offer the same advanced precision and robust data models, which will help keep building occupants comfortable and temperature-sensitive environments or materials safe.

Humidity Sensors

Humidity sensing systems are an often overlooked area of building climate control, but quality humidity sensors are no less essential than thermostats, CO₂ sensors, fire detectors, VOC sensors, and the like. The relative humidity (RH) of an indoor environment impacts occupant comfort, personal safety, and even the integrity of sensitive materials or equipment. For example, hospitals with high humidity are at risk of breeding mold or creating environments conducive to pathogen growth. A laboratory setting, on the other hand, may require higher humidity than most people find comfortable. 

A network of humidity sensors helps you to better optimize the RH of your indoor climate. Here are a few priorities to set when evaluating humidistats, duct humidity sensors, wall humidity sensors, and more:

• Field-Replaceable: Minimize downtime with humidity sensors that feature field-serviceable and field-replaceable components.  Delicate materials in museums, printing shops, and other locations can’t wait for inefficient maintenance.  In populous structures like schools, the comfort of hundreds hangs in the balance.

• Multi-Purpose: While an RH sensor has value on its own for humidity control, you’ll get more from your sensor with a combination platform that can be fitted to sense both humidity and temperature from the same device.

• Compatible: Versatile humidity sensor outputs makes them easier to work with your existing humidity controller or BAS. Whether you need 4 to 20mA, 0-5Vdc, 0-10Vdc, resistive temperature, BACnet MSTP, or Modbus RTU, a high-compatibility sensor system will be able to accommodate your needs.

The Veris HW2 series of indoor RH sensors was designed to bring all of these qualities to a simple, easy-to-install wall humidity sensor. You’ll  also have the freedom to select from three interface options to suit your needs, including a color touchscreen, three-button LCD display, or a subtle non-display (blank face) sensor that’s exclusively controlled through the BAS. Veris humidity sensors can be used to:

• Track both temperature and RH data with fewer devices
• Protect sensitive environments with field-selectable setpoints
• Optimize HVAC efficiency and save money with predictive maintenance

A detailed long-term data model of the indoor climate, from a multi-sensor system, is the best way to monitor and maintain a consistent, comfortable, or ideal atmosphere in climate-dependent facilities. If you’re looking for an efficient humidity sensing solution, take a closer look at these leading wall humidity sensors in our HW2 series of humidity sensors:

• HW2TA2A
• HW2TP2A

Indoor Air Quality Sensor Platform Interfaces

Your complete network of indoor air quality sensors will likely include devices in a wide range of locations, from room sensors in highly trafficked lobby areas to duct sensors in remote maintenance areas or unreachable wall sensors near the ceiling of large rooms.  For this reason, it’s best to use a sensor platform that offers a choice of interfaces to suit the needs of each individual device.

The Veris IAQ room sensor platform, for instance, offers these three interface options:

• Touchscreen Display: A modern touchscreen sensor interface brings flexibility and intuitive in-the-field operation to a wall mounted sensor. A backlit high-resolution display makes the sensor touchscreen easier to read than LCD, and provides a sleek aesthetic to your network of air quality sensors. The touchscreen interface also offers an innovative stoplight feature with a color-changing background to indicate CO2 status.

• 3-Button LCD Display: LCD is a cost-effective solution with a convenient and straightforward 3-button operation. They’re simple to operate while technicians are wearing gloves and perfect for economically-minded installations.

• Non-Display: A blank-face sensor is best for areas in which you do not want room occupants to access or operate the settings on the sensor device. These are also useful for placing subtle sensors in locations that would be difficult to operate in the field (such as near the roof in a tall ballroom).

It’s possible to mix and match sensor interfaces throughout your installation, so that each device is optimized for the context. If you need more information, check out our brief guide on choosing an IAQ sensor platform.

Find the Right Indoor Air Quality Solution with Veris

Indoor air quality doesn’t need to be complicated. If you have any questions we haven’t answered here, or want to learn more about IAQ sensors, installation, integration, interfaces, outputs, or anything else, don’t hesitate to contact Veris for help. Our expert team is always available to offer personalized advice or guide you towards the right solution for your building.

Looking for some of the indoor air quality sensors we’ve discussed? You’ve come to the right place. Shop online now for sensors in the category you need:

• CO2 Sensors
• VOC Sensors
• Temperature Sensors
• Humidity Sensors
• Shop All Products

Veris is committed to providing high-quality energy, environmental, and IAQ sensor solutions at the right price for your budget. Our knowledgeable staff will work with you on a custom order scaled to the precise needs of your facility and your BAS. And if you’re ever in need of technical support, simply contact us and we'll be ready to help.

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