Category: Air Quality Monitor

uRADMonitor SMOGGIE-PM | Call for Volunteers Take 2 [Ended]

Sotirios Papathanasiou14 Comments

Back in 2019 uRADMonitor and I organized a “Call for Volunteers” where we gave away 10 monitors all around the world.

Once more we are looking for five volunteers who want to receive a Smoggie-PM monitor. The new version comes with new transparent icy look case and visual indication of the pollution concentration thanks to the LED light.

Volunteers all around the world who are willing to install an Air Quality Monitor in their backyard or balcony or window or any other outdoor environment in order to build a better air quality network and to help you raise awareness in your neighborhood/community.

The only requirement from your side is to have a good Wi-Fi internet connection 24/7 and keep the device on constantly in order to broadcast the measurements to an open map. The WiFi signal must reach the monitor outdoors.

Just email or tweet or DM me on any social media platform, tell me where are you planning to install the monitor and why should I choose you.

What is SMOGGIE-PM?

Smoggie-PM is an ultra low-cost high performance Air Quality Monitor, with Wi-Fi connectivity and a laser scattering sensor (Plantower PMS5003) that measures Particulate Matter PM1, PM2.5 and PM10 and makes it available on your phone or laptop in real time. Also, it is equipped with a Temperature/Humidity/Pressure sensor (Bosch BME280).

Smoggie is an automated, fixed, Air Quality monitoring station. It has WiFi connectivity to send the air quality measurements to the uRADMonitor Cloud in real time. It needs 5V to run, powered by a standard micro-USB cable (the same your smartphone uses in order to charge it). The new versions have a color LED light that reflect the pollution levels in real-time.

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

Sotirios Papathanasiou4 Comments

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.

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Review: HA500 Air Purifier by Healthy Air Technology

Sotirios Papathanasiou13 Comments

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
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Clarity Node-S Remote Calibration Process

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When you use low-cost monitors for professional reasons, you need to calibrate them in order to obtain the best possible measurements. This process makes data less vulnerable to environmental conditions and more valuable to scientists and policymakers.

Clarity takes this process really seriously, and they dedicate a lot of resources to making sure their devices will measure accurate data (for more on how to assess air quality sensor accuracy, see this blog). I ask Clarity to perform a remote calibration on my Node-S and guide me through the entire the process.

I have discovered something interesting during that process about the local air quality station.

As you may already know from my previous articles, my local air quality station ES1393A is placed inside a park and it is almost surrounded by trees. Trees act as a barrier, and they block pollutants from reaching the monitors. The Clarity team told me that this was an especially complicated calibration. I suspect it has to do with the location of the station and how trees may interact with low-cost sensors.

The type of trees in my city is a variation of a ficus called ficus retusa l. var nitida. These trees release a resin from their leaves which can create interference to the low-cost sensors that do not have a filter to keep them out as the scientific-grade monitors do. Most outdoor scientific-grade monitors come with a debris screen inlet or an Inlet Heater which may capture the resin from the trees.

The problem is not the trees but the location of the air quality station that shouldn’t have been there.

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Shopping Guide: Air Quality Monitors

Sotirios Papathanasiou15 Comments

As you already know, I receive messages from readers of my blog almost every day. Their most common question is which air quality monitor should they choose. Most of the time in their message, they tell me that they go through Amazon to find a product, but they are confused from their reviews.

Carbon Dioxide (CO2) Monitors are a big hit nowadays due to the pandemic and because they are great tools at helping us understand indoor ventilation in order to mitigate the spread of the virus. Many new CO2 monitors pop up every day like mushrooms. Are they good, well …. you have to be careful!

No offense to Amazon or AliExpress or Facebook but most of their products are garbage for two reasons. Firstly, they are cheap products that come from China but without any quality control. Apple products come from China too, but Apple controls the quality of the shipping products. I have reviewed some cheap air quality monitors here on the blog just to justify their low price tag. Secondly, companies that sell these products don’t offer any kind of support nor updates. If the product has a small bug, you will stick with it forever. Many times the language they come with is badly translated or they come in Chinese if you are not careful enough during the purchase process.

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How to Use CO2 Monitors

Sotirios Papathanasiou2 Comments

I see a lot of pictures on social media platforms where people measure Carbon Dioxide (CO2) concentrations in indoor environments incorrectly.

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AQ Monitors meet Apple HomeKit

Sotirios Papathanasiou4 Comments

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?

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Review: Kaiterra Sensedge Mini for Business and Green Buildings

Sotirios Papathanasiou7 Comments

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.

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In-Depth Review: Wynd Halo 1st Edition Sensors

Sotirios Papathanasiou6 Comments

The Wynd Halo 1st Edition uses a proprietary PM sensor with a blue-light laser instead of a red-light laser, which presumably makes it more accurate and precise. Interestingly, I remember during the Kickstarter campaign of the monitor, backers were asking the company if they will sell the sensor as a component part to third parties, and they said yes because it was about to revolutionize the industry.

Although I don’t have a reference monitor, the comparison I conducted is considered a field evaluation in a real-life situation. AQ Monitors are designed to operate inside apartments and buildings for this reason I personally value more a field evaluation in situ than a lab evaluation where every parameter is controlled.

This kind of evaluation won’t tell us how accurate is the sensor, but it will reveal the correlation against other monitors in order to determine if measure something respectable. For example, there are many field and lab evaluations for the commonly found Plantower PMS5003 sensor that demonstrate a correlation of 0.78 – 0.93 against various reference monitors.

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Study: Taking a closer look at the air quality in classrooms

Sotirios Papathanasiou4 Comments

After almost two months of asking local schools for permission to install air quality monitors in their classrooms, on the 4th of December, a local school decided to grant me access.

In my city, Almeria, Spain, there are about 110 schools. I didn’t apply to all of them because each time I managed to find a way to contact them, I had to arrange a meeting in order to explain to them what I wanted to do, and all this process takes time. I managed to contact nine schools.

For this study, schools didn’t have to pay anything, so money wasn’t the issue for their refusal. They were worried about what will happen if the results were disappointing and negative. I tried to explain to them that the aim of the study is to understand what is going on in the classroom, in real conditions, with real students. I don’t want to discredit the school either the local authorities that manage the budget for the school. For this reason, I will keep the name of the school private.

Monitors

The monitors that I have installed for the study are made by Airthings. There are two Wave Plus, which include a CO2 sensor by Senseair. The sensor is called Sunrise, and it is an ultra-low-power, high precision NDIR sensor. Accuracy (CO2) ±30 ppm ±3% of reading. Finally, it features a self-correction system that allows them to auto-calibrate every 180 hours. I also have included a Wave mini monitor in the teacher’s office room. 

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