Monitoring Indoor CO₂ Concentration Levels in Offices & Schools Amid Climate Change—Battery-Powered DIC HatteTotte™ Active Wireless IoT Sensors Deliver Cost Effective, Easily Deployable CO₂ Monitoring Solutions for Indoor Environment Control

2024.01.31 Technology
Monitoring Indoor CO₂ Concentration Levels in Offices & Schools Amid Climate Change—Battery
Monitoring Indoor CO₂ Concentration Levels in Offices & Schools Amid Climate Change—Battery

Indoor environmental control sensors are the key element that determine the effectiveness of systems designed to manage optimal indoor air quality in modern built environments. Researchers now suspect that rising carbon emissions in the era of global climate change are impacting human health and wellness in indoor environments to a far greater extent than previously thought, even at the current global standard, 1,000 parts per million (ppm).

In 2017, anticipating the need for greater flexibility in delivering more fine-grain data in indoor environmental sensors, product developers at DIC Corporation (DIC) began developing a new type of indoor environmental sensors that would allow users to deploy far more sensors, faster, and more easily, without damaging facilities. DIC named this new type of wireless IoT sensors, HatteTotte—formed from the te-form of the Japanese verbs 貼るharu (to affix) and 取るtoru (to remove).

The CR2477 lithium coin cell battery-powered wireless IoT sensor DIC HatteTotte™ ES5000LW-IC2TH
ships together with DIC DSA double-sided adhesive tape for easy installation nearly anywhere.

DIC commenced domestic sales of two HatteTotte active wireless IoT sensor models in 2021. DIC’s Hidefumi Nishi, who led DIC Corporation’s wireless IoT sensor development initiative between 2017 and 2023, describes DIC HatteTotte™ CO₂/Temperature/Humidity Sensor ES5000LW-IC2TH as “Unique, soft-to-the-touch, inconspicuous IoT sensors well-suited to most indoor environments: Just affix a HatteTotte to any indoor surface for fully wireless connectivity, without using screws or other messy adhesives, to secure as many CR2477 lithium coin cell battery-powered environmental sensors as you need. HatteTotte wireless IoT sensors use the LoRaWAN long-range wireless protocol for secure long-range data transmissions.”

“We might be a bit early to the game, but we believe that we’ll see rapid growth in the market for CO₂ monitoring. True to the name HatteTotte IoT sensors are extremely easy to install and—100 percent removable—just as easy to remove. Moreover, you can just as easily add additional sensors to your sensing network without worrying about wiring or other power issues.”

“We’re now looking for partners outside Japan, notably in the United States or Europe, who might be interested in working with us to deploy HatteTotte IoT sensors in their local markets where the demand for indoor CO₂ monitoring is on the rise.”

Whether you’re a property owner, building operator or manager, or renter, you can easily install HatteTotte IoT sensors in any room. “We’re now looking for overseas partners notably in North America and Europe where stricter regulations are already enforced by government agencies, such as the Occupational Safety and Health Administration (OSHA) or National Institute of Occupational Safety and Health (NIOSH), and industry associations, such as the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).”

As high atmospheric carbon dioxide (CO₂) concentration levels both outdoors and in confined/poorly ventilated spaces are known to produce harmful effects in human beings, government health and safety agencies as well as building owners and operators around the world are taking steps to maintain healthy building environments.

In the United Kingdom, the Royal Institution of Chartered Surveyors (RICS) cites elevated indoor CO₂ levels “as an indication of insufficient dilution of airborne pollutants such as volatile organic compounds (VOCs) and other bio-effluents, which are emitted or brought into a space by occupants.”

The first step toward maintaining health standards for indoor environments is the installation of monitoring systems, and a key element of each monitoring system is the sensors. Whether outfitting an existing building or planning a monitoring system for a new building, the ability to flexibly install new/additional sensors is vital to creating efficient systems capable of delivering accurate fine-grain data.

Here, the wireless active IoT sensor DIC HatteTotte™ CO₂/Temperature/Humidity Sensor ES5000LW-IC2TH delivers. Shipped together with DIC DSA double-sided adhesive tape for easy installation nearly anywhere.

What is Carbon Dioxide (CO₂)?

Consisting of one carbon atom and two oxygen atoms, carbon dioxide (CO₂) is a natural, colorless, odorless vital gas occurring naturally in our Earth’s atmosphere. Moreover, CO₂ is a critical substance both inherently for life on our planet and more recently for many modern industrial processes.

Though minimally toxic at normal atmospheric concentrations, because CO₂ can also act as an asphyxiant—reducing/displacing oxygen—it becomes more harmful in high concentrations in enclosed spaces. So, though CO₂ not a pollutant, it can greatly impact human health at very high concentrations with extended exposure, especially in confined spaces without proper ventilation.

While global exchanges between the atmosphere and water primarily governs CO₂ levels on Earth, breathing more directly affects indoor CO₂ concentrations. As an average human being exhales normally, that air contains approximately 3.8% or 38,000 ppm (parts per million) of carbon dioxide. However, in normal situations, with rapid mixing with the surrounding air, such high CO₂ levels usually reduce quickly to much lower concentrations.

In modern built environments, indoor CO₂ levels usually range between 400 ppm and 2,000 ppm, while outdoor CO₂ levels average 400 ppm. However, in urban areas, modern chemical and industrial processes as well as the combustion of fossil fuels can elevate CO₂ levels by up to 15%. This increase is the reason the world’s 100 largest cities produce some 18% of all global carbon emissions.

A July 2019 study, Direct Human Health Risks of Increased Atmospheric Carbon Dioxide, published in Nature Sustainability (VOL 2, AUGUST 2019) identified the following adverse health outcomes related to exposure to increased CO₂ concentrations in indoor environments:

Acute Exposure Adverse Health Outcomes CO₂ Level Duration
CO₂ retention 1,000 – 5,000 ppm Under 4 hours
Inflammation 2,000 – 4,000 ppm 2 hours
Cognitive decline 1,000 – 2,700 ppm 1 - 6 hours
Chronic Exposure Adverse Health Outcomes CO₂ Level Duration
Chronic, low-grade systemic inflammation Approx 3,000 ppm 13 days
Bone demineralization and kidney calcification 2,000 – 3,000 ppm 60 – 90 days
Behavioral changes/physiological stress 700 – 3,000 ppm 13 – 15 days

Statistics from Nature Sustainability (VOL 2, AUGUST 2019)

What Are Wireless Active IoT Sensors and How Do They Work?

Most users deploy wireless sensors to measure specific parameters in each sensor’s immediate surroundings, producing data for additional processing. Parameters most often include ambient conditions such as air temperature or air quality. IoT sensors are typically divided into either active (requiring external stimulation) or passive, analog or digital. Digital active IoT sensors measure or detect changes such as environmental conditions or electrical signals, etc.,

These changes are converted into optical or electrical signals, generating output that is processed by a microcontroller. The microcontroller converts analog input to digital signals, and these signals are processed to extract data/generate output that is sent to the IoT platform. Wireless IoT sensors typically transmit using either short range (e.g., Bluetooth, Wi-Fi) or long range (e.g., LoRa, Cellular) wireless protocols to securely connect and share data between IoT sensors, devices, and applications.

What Are CO₂ Sensors and How Do They Work

There are three types of CO₂ sensors: electrochemical, photoacoustic spectroscopy, and nondispersive infrared (NDIR) carbon dioxide sensors. DIC HatteTotte™ CO₂/Temperature/Humidity Sensor ES5000LW-IC2TH is a nondispersive infrared (NDIR) carbon dioxide sensor, monitoring the absorption of infrared light at a wavelength of 4.3 microns (μm)—a wavelength well-suited to very strong CO₂ absorption. If HatteTotte™ ES5000LW-IC2TH absorbs infrared light, CO₂ is present; the more infrared light HatteTotte™ ES5000LW-IC2TH absorbs, the higher the CO₂ concentration level. HatteTotte™ ES5000LW-IC2TH then wirelessly transmits this data to the installed control system.

Using IoT Sensors for Indoor Environment Control

Internet of Things (IoT) sensors offer the ideal solution for monitoring CO₂ levels indoors. Here, DIC Corporation has developed HatteTotte™—a new type of IoT sensor that is quickly deployable and easily re-deployable thanks to DIC double-sided industrial adhesive tapes, notably the DIC DSA series of double-sided adhesive tapes specifically designed for easy disassembly.

Using DIC DSA double-sided adhesive tape, affix DIC HatteTotte™ IoT sensors nearly anywhere.

What is the acceptable level of CO₂ in the workplace?

Rising carbon emissions are already impacting the built world: Climate change is effectively driving more people indoors with more people working and studying closer proximities, increasing CO₂ levels in confined spaces. And as outdoor CO₂ concentrations have a direct impact on a facility’s indoor concentrations, climate changes will further impact these concentrations.

Government agencies and building industry associations in the United States and the United Kingdom have already begun to prepare for this new reality. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)—a global society advancing human well-being through sustainable technology for the built environment, focused on building systems, energy efficiency, indoor air quality, refrigeration, and sustainability—uses CO₂ levels as an indicator of ventilation.

Formulated specifically to protect a worker’s health and safety for up to a 10-hour work shift, during a 40-hour workweek, over that person’s entire working life, America’s National Institute of Occupational Safety and Health (NIOSH) rules and laws cover employee carbon dioxide exposure in the workplace.

ASHRAE recommends indoor CO₂ concentrations at or below 1,000 ppm in schools and 800 ppm in offices in the United States. The Occupational Safety and Health Administration (OSHA) is uniquely interested in the health and safety of all employees in commercial workspaces.

In the United Kingdom, the British government included CO₂ monitors in its revised requirements for maintaining indoor air quality in English Building Regulations on Ventilation: Approved Document F, which took effect in June 2022—marking the first time the UK government has legally required continuous indoor measurement of indoor air quality.

Hidefumi Nishi notes, “Office owners, corporate general affairs departments, commercial facility owners, facility management companies, school-related government agencies, and nursing home operators alike all need fine-grain CO₂ monitoring sensors to maintain healthy working/learning environments—as high CO₂ concentrations decrease brain function. HatteTotte wireless IoT sensors can also help alert authorities monitor the ventilation status for infection control, or better understand the movements and concentrations of people throughout the day.”