Measuring Air Quality: Diy Home Pollution Detection Methods

Air pollution is a pressing issue, and maintaining good indoor air quality is fundamental to our health. Spending a significant amount of time indoors means that the air we breathe within our homes, offices and other buildings needs to be kept clean. There are various ways to measure and improve indoor air quality, from using personal air quality sensors to trying out DIY methods like observing signs of poor air quality such as excessive dust, condensation or mould growth.

Use a personal pollution sensor to measure indoor air quality

Personal pollution sensors are a great way to measure indoor air quality. They are smaller and more accessible than government-issued sensors, allowing individuals to measure the quality of indoor air and track their exposure over time. This can help you better protect yourself and your family from harmful pollutants.

There are a variety of personal pollution sensors available on the market, and they differ in terms of precision, cost, and size. Some sensors are designed to be carried on a keychain or necklace, while others are larger devices that are placed in a fixed location in your home. When choosing a sensor, it is important to consider the type of pollutants you want to detect, as different sensors may be more or less sensitive to certain pollutants.

For example, the Flow sensor by Plume Labs measures particulate matter (PM10, PM2.5, and PM1), NO2, and VOCs. It uses two different techniques for measuring air quality: laser diffraction for fine particles and measuring the conductivity variations of metal oxides for NO2 and VOCs. The Atmotube PRO is another portable indoor and outdoor air quality monitor that detects fine particles and volatile organic compounds (VOCs) and reports them in real time. It also has an app that instantly alerts you when dangerous pollution levels are detected.

When using a personal pollution sensor, it is important to follow the manufacturer's instructions for placement and use. It is also important to understand the limitations of these devices, as they may not detect all types of pollutants. For example, a sensor that only measures particulate matter may not alert you to the presence of harmful gases like radon or carbon monoxide. In addition, the accuracy and precision of these sensors can be impacted by factors such as their location in the indoor space, time in use, and the presence of multiple contaminants in the air.

Overall, personal pollution sensors can be a valuable tool for monitoring indoor air quality and taking steps to improve the air you breathe in your home.

Download an air quality app, like AirNow, to monitor outdoor air pollution

If you're looking to monitor outdoor air pollution, the AirNow app is a great tool to have at your disposal. Available for free on both the Apple App Store and the Google Play Store, AirNow is a mobile application that provides real-time updates on air quality worldwide. Here's how it can help you monitor outdoor air pollution:

Air Quality Indicators

AirNow provides key air quality indicators, including the Air Quality Index (AQI), fine particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), and pollen levels. These indicators give you a comprehensive overview of the air quality in your region or any location worldwide.

Real-time Data

One of AirNow's standout features is its ability to deliver real-time data. The app retrieves information from reliable sources and updates it continuously, ensuring that you have precise and current air quality information. This feature is particularly useful for staying informed about changing air quality conditions and making timely decisions to protect your health.

Detailed Forecasts

In addition to real-time data, AirNow offers detailed forecasts on air quality trends for the next three to four days. These forecasts empower you to plan your activities accordingly, especially if you are sensitive to air pollution or are an active sports enthusiast. For example, you can use the forecasts to decide whether it's advisable to spend extended periods outdoors or if it's better to stay inside due to poor air quality.

Interactive Map

The AirNow app includes an interactive map feature that provides data for air quality for PM 2.5, PM 10, and ozone monitors in the United States, Canada, and Mexico. By tapping the map icon on the bottom of the screen, you can easily access this information and make informed decisions about your outdoor activities and travel plans.

Personalized Advice

AirNow goes beyond just providing data by offering personalized advice based on the air quality in your area. If you are an active individual, the app will inform you about optimal conditions for outdoor activities. On the other hand, if you are sensitive to air pollution, AirNow will provide specific recommendations to help protect your health, such as suggesting indoor activities when pollution levels are high.

Multiplatform Availability

To ensure accessibility, AirNow is available on multiple platforms, including iPhone and Apple Watch. This means that you can access critical air quality information wherever you are and at any time. Whether you're an athlete, a health-conscious individual, or simply a concerned citizen, AirNow empowers you to stay informed and make well-informed decisions for your health and well-being.

Purchase a VOC meter to measure volatile organic compounds

Volatile organic compounds (VOCs) are common indoor air pollutants that can be released from household products like paints, furniture, carpets, and plastics. They can cause adverse health effects, including headaches, fatigue, nausea, and even more serious conditions like cancer, liver damage, and central nervous system damage. As such, it is important to monitor their presence in your home.

VOC meters are crucial in monitoring volatile organic compounds and can be purchased online. They are electronic monitoring devices that detect the presence of VOCs in the air, helping to ensure the safety of those in the environment. VOC meters are available in handheld, portable, fixed, and semi-portable varieties, with prices starting at around $150.

When choosing a VOC meter, it is important to select a reliable model that is properly calibrated to a national standard. While more affordable options exist, these may lack specificity and proper calibration, leading to unstable and non-repeatable readings.

There are two main types of VOC sensors: PID sensors and electrochemical sensors. PID sensors are superior but more expensive, breaking down VOCs in the air into positive and negative ions using an ultraviolet (UV) light source. They can detect down to 0.001 ppm and have a high sensitivity (ppb) and a wide dynamic range. Electrochemical sensors are more affordable and accessible, detecting down to 0.01 ppm, but they are not as sensitive as PID sensors.

In addition to purchasing a VOC meter, you can also use a sorbent tube for air capture, which can then be sent to a lab for analysis. This method is more time-consuming but may provide more accurate results.

By using a VOC meter or conducting a lab test, you can identify the presence and levels of VOCs in your home and take the necessary steps to reduce exposure and create a healthier environment.

Invest in a CO2 meter to measure carbon dioxide levels

Carbon dioxide (CO2) is the current standard for measuring indoor air quality. High carbon dioxide levels indicate a lack of fresh air in a building, which can correlate with high levels of airborne dust, mould, bacteria, and other indoor air pollutants. To measure the amount of CO2 in the air, you can use a CO2 meter, also known as an indoor air quality monitor.

CO2 meters contain small sensors that use infrared technology to measure CO2 levels. These devices vary in price, ranging from $50 to $500, and come in several types, including handheld, desktop, or wall-mounted units. Some meters may also measure other factors such as temperature, dew point, humidity, or volatile organic compounds (VOCs).

When choosing a CO2 meter, consider factors such as accuracy, range, and ease of use. Look for a device that is easy to maintain and has a good battery life. For example, an NDIR (non-dispersive infrared) CO2 meter with an ABC (automatic background calibration) feature will recalibrate itself weekly, guaranteeing accurate readings over many years of use.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) sets standards for recommended indoor CO2 levels. According to ASHRAE, indoor levels should be kept below 1,000 ppm in schools and 800 ppm in offices for optimal air quality. Normal outdoor air typically has around 400 ppm of CO2, while occupied spaces with good air exchange usually have levels between 400 and 1,000 ppm.

By investing in a CO2 meter, you can easily and accurately measure carbon dioxide levels in your home and take steps to improve indoor air quality, such as increasing ventilation or using air purifiers.

Use a hygrometer to measure air moisture/humidity

A hygrometer is a device that measures the humidity of the air, or the amount of water vapour in the air. It is an important tool for maintaining good air quality at home, as too much moisture in the air can damage human skin and bodies, while too little moisture can cause discomfort and health issues.

There are several types of hygrometers that can be used to measure air moisture and humidity:

Mechanical Hygrometers

Mechanical hygrometers utilise organic substances, particularly finer substances such as goldbeater's skin (ox gut) and human hair, which contract and expand in response to changes in humidity. The contraction and expansion of the hair element cause a spring to move the needle on the dial, indicating the relative humidity.

Electrical Hygrometers

Electrical hygrometers measure changes in electrical resistance in a thin layer of lithium chloride or a semiconductor device as humidity levels fluctuate. These devices can also sense variations in weight, volume, or transparency of various substances that react to changes in humidity.

Dew-Point Hygrometers

Dew-point hygrometers consist of a polished metal mirror that is cooled at a constant pressure and vapour content until moisture begins to condense on its surface. The temperature at which condensation starts is the dew point, indicating the relative humidity.

Psychrometers

A psychrometer, or wet-and-dry-bulb thermometer, uses two calibrated thermometers, one dry and one kept moist with distilled water. When the air temperature is above freezing, the wet-bulb thermometer will be at a lower temperature than the dry-bulb due to the evaporation of water from the wick. Relative humidity can be computed using the ambient temperature and the difference in temperature between the two thermometers.

Metal-Paper Coil Hygrometers

This type of hygrometer is commonly found in inexpensive devices and offers limited accuracy. It uses a salt-impregnated paper strip attached to a metal coil to absorb water vapour, causing the coil to change shape. These changes are indicated on a dial, typically by a metal needle.

Hair Tension Hygrometers

Hair tension hygrometers use a human or animal hair under tension to measure humidity. The hair is hygroscopic, meaning it tends to retain moisture, and its length changes with fluctuations in humidity. The length change can be magnified by a mechanism and indicated on a dial or scale.

By using any of these types of hygrometers, you can effectively measure the air moisture and humidity in your home, helping to ensure a comfortable and healthy living environment.

Frequently asked questions