Review: View Plus by Airthings

View Plus is the flagship air quality monitor from Airthings which was designed to address as many indoor parameters as possible and it complies with Green Building Certification.

The philosophy behind Airthings air quality monitors is simple. They try to make B2C and B2B clients’ life easy. One clear example is that all monitors, including the View Plus, work on simple AA batteries in order to avoid installation fees (from construction workers) and ugly cables running all over the walls.


  • Particulate Matter (PM2.5) Laser OPC Sensor 0-500 μg/m3
  • Carbon Dioxide (CO2) NDIR Sensor 400–5000 ppm
  • Volatile Organic Compound (VOCs) Metal-oxide Sensor 0-10000 ppb
  • Temperature Sensor
  • Humidity Sensor
  • Air Pressure Sensor 500-1100 mBar
  • Light Sensor
  • Hand Gesture Sensor
  • Noise Sensor 35 – 120 dBA SPL
  • E-Ink 2.9″
  • RGB LED Indicator
  • 6 AA batteries or USB-C
  • Mesh SmartLink and Bluetooth LE
Read More »

Review: AirAssure an Indoor AQ Monitor by TSI

Someone may ask what more they can offer to an already saturated market of air quality monitors. The answer is simple: Experience! TSI Incorporated is a USA-based company with more than 60 years of experience and knowledge thanks to the 1000 researchers and engineers that work for the company worldwide. They hold more than 50 patents.

Recently, TSI released the AirAssure which is an IoT-enabled Indoor Air Quality Monitor (AQM) designed specifically for buildings that really need to have an in-depth and accurate view of the indoor air quality. The monitor comes in two versions the 4-gas and 6-gas variation. I am going to review the 4-gas AirAssure IAQM that comes with a Formaldehyde, Carbon Monoxide, Carbon Dioxide, and Total Volatile Organic Compounds sensors. Apart from the 4 or 6 gas sensors configurations, all versions come with a particulate matter sensor and a temperature/humidity/barometric pressure sensor. Also, a new CO2 and VOC model will be released this autumn.

Technical Specs 4-Gas AirAssure

  • Formaldehyde (CH₂O)
  • Carbon Monoxide (CO)
  • Carbon Dioxide (CO2)
  • Total Volatile Organic Compounds (tVOC)
  • Particulate matter (PM)
  • Temperature, Relative humidity and Barometric pressure
  • Universal USB-A Power Adapter
  • USB-A to USB-C Cable
  • USB-C port
  • Included 32GB Removable micro-SD
  • 24 VAC Terminal Connector
  • Colour LED Lights
Read More »

Comparison: CO2 Monitors – Why do we need them in indoor environments?

I should have written this comparison a long time ago, but I was very busy the past few months. A lot of you have insisted, so here it is.

A CO2 monitor is the number one tool that can help us understand ventilation rates in indoor environments and consequently mitigate the spread of airborne viruses like coronavirus (SARS-CoV-2), but let’s not forget the common flu either.

Carbon Dioxide CO2 can decrease our cognitive ability. The correlation between CO2 and productivity has been studied a lot for over 50 years by many academics. Interesting facts, the design standard for CO2 levels in most buildings is 1000ppm but the recommended concentration is below 700ppm. In one of the studies, Harvard researchers have found significant negative impact at 930 ppm.

According to World Green Building Council, they estimate the reduced absenteeism through sick days to be worth ~$35/m2. Again the World Green Building Council estimates that if employees’ productivity improves by even a 5% because of better IAQ, that alone would be worth ~$400/m2.

The monitors are divided into two categories, the ones that can be carried with you (portable/wearable) and the fixed ones and in most cases professional solutions. Each monitor offers different characteristics. Sometimes just because it has more features, it doesn’t mean that it is the right tool for you.

Most of the monitors offer much more than just CO2 monitoring. We spend a lot of time indoors and a more holistic approach is needed sometimes when it comes to indoor air quality (IAQ) or indoor environmental quality (IEQ).

The monitors are:


The CO2BUDDY is the only wearable CO2 monitor that can be used in so many places and for a variety of reasons. Very important for professionals that work in places where the conditions are extreme. Closed or crowded indoor spaces.

Aranet4 HOME

Aranet4 is a small and portable CO2 monitor that surprises people. It can be used as an indicator of productivity in schools and office buildings. It is packed with smart features for those that want to log measurements and share them later on.

Awair OMNI

Awair OMNI is a well-thought product that has one aim, to help professionals see the air and address potential issues. The Awair Display Mode allows users to display any information from the monitor to a big screen inside a bar, restaurant, office, school, etc. It features up to 8 hour battery and logs data on-device. It complies with the most common certifications from WELL V1, LEED, Fitwel, LBC, and RESET.

Ethera Labs TX mini

The Ethera Labs XT Mini ensures quality and competitive monitoring systems with great cloud platforms for all needs and budgets. By connecting the monitor to BMS, they manage to achieve energy efficiency while directly managing the ventilation system, as well as portable air purifiers. It is the only monitor that can be connected to a PC via USB and upload data locally.

Kaiterra Sensedge mini

The Sensedge Mini is a great and accessible choice for those that wish to get or not air quality certification by RESET, LEED, WELL, and others as the monitor complies with their requirements. The removable sensor modules reduce maintenance costs and ensure accuracy, something really important when you want to offer comfort and health to the building’s occupants.

Airthings Wave Plus

Airthings Wave Plus is designed for professionals and homeowners (different plans). It offers a great dashboard that makes air quality data comprehensive. Excellent low power CO2 sensor that runs on two AA batteries for up to 16 months and the colour LED ring can indicate the high CO2 levels. Additionally, it can measure Radon which is a radioactive gas.

Analox Air Quality Guardian

The Air Quality Guardian comes with a large LCD display that provides plenty of clear information for those professionals that don’t have the luxury of time to continually take their phones out of their pockets in order to check the CO2 concentrations and trends. Very loud alarm and great traffic light system🚦 where 3 LED lights will turn on depending on the concentration of CO2 in the indoor environment.

airthinx IAQ

Airthinx IAQ is designed for professionals, however, it is also available to homeowners too. The dashboard offers so many features that can really help you build a solid business model around it as you can rent the device(s) to third parties. The company provides a solid ecosystem of hardware and software, hard to resist.

Quick Comparison

All monitors deliver great CO2 measurements as I have tested them all. They all feature a non-dispersive infrared (NDIR) sensor which is the best among the low-cost sensors because of their accuracy and low-power consumption.

Each monitor has unique features, so read each review individually to discover if it is the right fit for you.

Review: Aranet4 HOME – CO2 Monitor [EN/ES/GR]

(Scroll down for the Spanish or Greek version of the review/Desplácese hacia abajo para la versión en español o Griega/ Μετακινηθείτε προς τα κάτω για την ισπανική ή την ελληνική έκδοση της αξιολόγησης)


It is not a coincidence that everywhere you look nowadays you see a small, square, and white monitor with a screen in the middle that displays some numbers! Well, this is Aranet4 which was developed by a Latvian company.

Aranet4 is a small and mighty CO2 monitor that surprise people for two reasons. First of all, it is very comprehensive, and secondly, most people are intrigued by the technology of the display as it uses an e-ink display and, to the untrained eye, looks like a simple sticker.

The commonly found AA batteries can operate the monitor for up to 2 years so you don’t have to worry about them. It uses a single channel non-dispersive infrared (NDIR) sensor technology for accurate CO₂ measurements, read more here.


  • Carbon Dioxide (CO2) NDIR
  • Temperature (ºC/ºF)
  • Relative Humidity
  • Atmospheric Pressure
  • e-ink Display
  • Bluetooth
  • Buzzer (Alarm)
  • AA Battery Operated (up to 2 years)
Read More »

Podcast Ep1: See The Air | Real Life Stories

I am very happy to announce that I am launching a new series of Podcast episodes where people from all around the world will be able to share their experience with air pollution and how it affects their lives.

The episodes will be available in all big Podcast distributional channels like Apple Podcast, Google Podcast, Spotify, and Spreaker.

Episode 1 : London, UK – Traffic Pollution and LTNs

In the first episode, we will hear Ediz from London, UK. Ediz is a clean air campaigner and he and his family members have to breathe lots of traffic-related air pollution as his neighborhood is jammed by hundreds of cars every day.

Read More »

Let’s talk: IoT Wireless Network Protocols for Air Quality Monitors

The Internet of Things (IoT) describes the network of electronic devices (air quality monitors, purifiers, motion detectors, cameras, etc.) that are embedded with sensors, software, and other technologies for the purpose of connecting and exchanging data with other devices over the Internet.

In this article, I am going to describe some of the available networks and physical layers that are used by Air Quality Monitors (AQM), mainly for consumer-based products, and discuss which technologies make more sense in 2021+ for Smart Homes/Buildings and Businesses.

Wi-Fi IEEE 802.11

IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) protocols and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) Wi-Fi computer communication in various frequencies including 2.4 GHz, 5 GHz, and 6GHz.

IEEE 802.11a/b/g/n

This standard wireless network protocol is among the most common protocols for communication between the devices and the internet/cloud. Most devices even today use the ~20 years old 802.11b or 802.11g with a linkrate between 1 to 54 Mbit/s and a frequency of 2.4 GHz for power conservation reasons and good wall penetration. The 802.11n transmits the highest data throughput, but at the cost of high-power consumption at 5GHz.

IoT AQMs do not need a high-speed data throughput because the information they transfer is very little and in the range of a few kilobytes. So protocols like the IEEE 802.11ac and IEEE 802.11ax don’t make a lot of sense because they demand energy and they don’t offer good wall penetration in order to cover an entry house/apartment.

IEEE 802.11ax aka WiFi 6 or 6e

There are some claims that IoT devices will adopt the new WiFi 6e (e stands for enhanced) but I don’t think we will see that happening as bandwidth isn’t relevant for AQMs but the range is more essential and the WiFi 6e is designed to cover approximately 30m/98ft indoors. The 6e operates at 6Ghz, as a result, the highest the frequency the shortest the distance a signal can travel within walls. A positive feature of this protocol is that it supports a Low Power Indoor (LPI) mode. In the multi-user scenario, the WiFi 6 module consumes only one-third of that of the Wi-Fi 4 (802.11n) module and they achieve that by shortening wake-up time.

Read More »

Review: HA500 Air Purifier by Healthy Air Technology

It is not always an easy task to keep indoor air free from pollutants, especially, when Nitrogen Dioxide (NO2) is present in indoor environments. In most cases, there is little you can do to eliminate NO2 and other gases like Sulphur Dioxide (SO2), Formaldehyde (TVOC), or even pathogens like H1N1 Influenza A virus (pandemic flu), and Staphylococcus aureus (or similar bacteria).

Here comes the HA500 Air Purifier by Healthy Air Technology which is able to eliminate all of these pollutants/pathogens from indoor environments. It does that thanks to the triple-layered system with a primary filter, HEPA 13 filter, and Pollution Eraser DNO filter. DNO means D-Orbital Nano Oxide which is made of two parts. 

1st part: The Carrier – Activated charcoal. The material that is used in military gas masks, and captures pollutants within the pores of the charcoal.
2nd part: The Transition metal oxides – Transition metal oxides are coated in the activated charcoal to form catalysts, and these catalysts break down pollutants and toxic gases into harmless chemicals and then release these harmless materials back into the atmosphere like water, oxygen, carbon dioxide, etc. The DNO is invented by the founding CTO of Oxford Catalyst plc (a leader in novel industrial catalysts).

HA500 Control Panel and Display
Read More »

AQ Monitors meet Apple HomeKit

I really like to have all AQ Monitors and other devices connected to one place in order to make my life easier when I try to figure out what is going on in my house. I am an iOS user which means this post doesn’t concern Android users, however, I will advise you to stick around and read the benefits of having Apple HomeKit.

Not all AQ Monitor manufacturers support HomeKit and here comes HomeBridge which is a platform to bring non-supported devices to Apple’s ecosystem. There are only a few AQM manufacturers that officially support HomeKit, like Kaiterra, Eve and QingPing.

The community of the HomeBridge has allowed others to take advantage of the platform and make the user experience even better by porting many more AQMs into HomeKit.

Which AQMs support HomeBridge?

  • Airthings
  • PurpleAir
  • Awair
  • Sensor Community (aka Luftdaten)

How to set up HomeBridge?

Read More »

Review: Kaiterra Sensedge Mini for Business and Green Buildings

There is a demand for Green Buildings lately, which focus on the comfort and health of the building’s occupants. Energy efficiency was the original target for most of the green buildings certifications programs, but they have evolved, and they now focus on many more aspects of the indoor environments. Indoor Air Quality has become the number one priority for many green building certifications, and in order to be certified, there are strict rules for ventilation and AQ monitoring.

Here comes Kaiterra Sensedge Mini, which is a RESET certified indoor air quality monitor. The Sensedge Mini is a calibrated real-time monitor that has to be placed in buildings that wish to obtain a Green Buildings certification.

The Sensedge Mini uses two removable sensor modules to replace the traditional, costly calibration processes for long-term accuracy with minimal maintenance.

Read More »

Things no one talks about: Flatulence and Indoor Air Quality

Have you ever wondered if the gases we produce as humans are toxic to those who live with us?

It is a taboo but I think we all have thought about it at one moment in our lives. Scientifically known as flatus but commonly known as a fart, many of us even use funny expressions to cope with this uncomfortable situation they create like Acid-rain maker, After the thunder comes the rain, Baking brownies, Death Breath, Fire a stink torpedo, pass the gas, etc…

Let’s take a step back and analyze the chemical composition of a flatus. More than 99% of the volume of flatus is composed of non-smelly gases. These include oxygen (O2), nitrogen (N), carbon dioxide (CO2) hydrogen (H) and methane (CH4), keep in mind, methane is a colorless, odorless gas and nitrogen is not produced in the gut, but it is a component of environmental air. The remaining trace (<1% volume) compounds give flatus its smell which comes from a combination of volatile sulfur compounds. Hydrogen sulfide (H₂S), methyl mercaptan (CH4S), dimethyl sulfide (C2H6S), dimethyl disulfide (C2H6S2), and dimethyl trisulfide (C2H6S3).Read More »