For the past couple of years, there has been a storm gathering on the horizon of indoor air quality monitoring. Nucleating around crowd-funding sites such as Kickstarter and Indiegogo, these devices seem to advect along roughly similar trajectories. The teams working on these projects have created a sort of high pressure system wafting high-quality industrial design onto the radar in this otherwise quiet market sector. The projects also drop a steady shower of Boostrap-inspired stylesheets and mobile apps.
There is, as yet, scant information about the sorts of sensors employed in most of these devices, what their range of sensitivity is, what their accuracy and precision, how they are calibrated, or virtually any useful technical detail. Nevertheless, they are out there. Consumers are clearly interested in this kind of data, and the early adopter crowd is putting hundreds of thousands of dollars down to get it. I thought I would do a little roundup of the twelve products I was able to find. Not all of these products are actually shipping yet, but I’ve done my best not to include any obvious… let’s call it vaporware.
In case anyone might want to study these things in more detail, I’ve compiled a table.
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AtmotubeAtmotube is a small, portable battery operated device, somewhat ironically housed in a case resembling a cigarette lighter. |
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Air MentorAir Mentor is a CO2, CO, VOC, PM2.5, PM10, Temperature, and Relative Humidity detector shaped like the rotor in a Wankel engine. It was developed by Taipei-based CoAsia Microelectronics. |
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Air.AirAir.Air is a football-shaped device developed by Shenzhen-based XINJI Computer Parts. The hole in the middle is, evidently, for an optical particle counter from Sharp Electronics. |
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FoobotFoobot is the first product from a small startup based in Luxembourg, also called Foobot. Follow Foobot on Twitter : https://twitter.com/myfoobot |
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SenslySensly is the only product I found in this category that targets SOx, NOx and ammonia, though I’m not sure if this is accomplished with targeted sensors or if they have a sensor with sensitivity to many such compounds. If the latter, then probably some of these other devices will also respond to SOx, NOx and ammonia. |
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CanaryCanary is mostly a sort of one-box home security system. You plug it in and connect it to your WiFi network, and it does the usual security stuff. It’ll do motion detection, let you monitor your stuff with a remote camera. They also included air quality monitoring features, on which additional details were… nebulous.With some digging, I was able to find that the thing evidently measures isobutane, ethanol and hydrogen, maybe VOCs, maybe particulates. It also seems to be able to measure carbon monoxide, but the company seems keen to avoid having people use it as a carbon monoxide alarm, which it is not certified to do. |
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BirdiConfusingly, this product used to be called Canary. This is basically a carbon monoxide alarm with some extra features — particulates, VOCs, temperature and humidity. |
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Withings HomeThe Withings Home is essentially a web-based baby monitor with some sort of “air quality” feature. I found no clear specifications of what it actually measures. |
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AwairThe Awair device is a recently crowdfunded monitoring device targeting particulates, VOCs, CO2, temperature and humidity. Follow the project on the Medium account. |
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TZOAThe TZOA-consumer is a wearable particle sensor, with some extra stuff, including a UV, ambient light, temperature and humidity. They also have a TZOA-research version with the same sensors, but with a bigger battery, more storage and the ability to attach additional sensors. |
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CubeSensorsCubeSensors won the TechCrunch Hardware Battlefield in 2014 with their cute little VOC, CO2, temperature, humidity, ambient light and pressure sensors packages. They come in packs to monitor multiple rooms! Gizmag did a detailed review back in July. |
Thanks, Russell, for this interesting post. It would be nice to know the parameters measured by each device.
Looking further into some of the devices, most seem to measure CO2 as an indicator of indoor air quality. CO2 indicates the relative rate of outdoor air ventilation per occupant compared with occupant density (people per occupied volume) and while it has often been used as an indicator of CO2, responsible authorities agree that it is not correct to rely on it as a measure of indoor air quality. People exhaled breath contains high concentrations (40,000 ppm) of CO2 normally, so that in a very densely-occupied indoor environment with a low outdoor air ventilation rate per person, the concentration of CO2 will be relatively high. (Remember, outdoor air typically contains between 370 ppm and 600 ppm depending on the location and other factors like vegetation density, combustion, wind, etc. It is higher in urbanized areas than in a forest in the daytime where trees consume CO2.
Human CO2 production correlates with human metabolic rate, so different sized people or people at different activity levels will produce (exhale) different amounts of CO2.
There is a widely accepted myth – often referred to as the ASHRAE standard – that above 1000 ppm CO2 levels, indoor air quality is unhealthy. This view is unfounded and interpretation of any CO2 concentration requires sophistication beyond that of the typical building occupant and even many professionals who provide advice on IAQ.
Interesting to note that many of the products sell for a price of $170 ± a few dollars. Does this suggest that their is a market price point that determines what manufacturers and their marketing outlets believe people will pay for a promise of good IAQ? or is it the unlikely (implausible) case that all these different technologies cost the same to produce, package, and market.
There is no one parameter that will provide a reliable, universal indicator or indoor air quality. The best thing people can do is to avoid buying and using products that contain harmful chemicals and to ensure adequate ventilation is present when use of such products is unavoidable. Many of the products most to be avoided are antimicrobials. Recent shifts in scientific views on the harmfulness of all microbes may eventually reduce the use of such chemicals.
Amazon.com or a web search for IAQ monitors provides a few other products of the same sort as those you have listed.
Check out the CSV file linked in the post — I’ve done my best to catalog the parameters targeted by each one. Unfortunately, most of the teams building these devices do not disclose the actual sensors used. Instead, most of them simply list the inferences they make from whatever underlying sensor tech they have incorporated into the device. It’s a bit frustrating. For example, the Sensly lists SOx and NOx as targets, but I have no idea if that means that their device targets each one, or if they have a broad spectrum sensor that detects “stuff like that.”
As for the price, I would attribute that to the nature of electronics manufacturing rather than a statement on what consumers thing IAQ monitoring is “worth.” The bill of materials for most electronics amounts to a small fraction of final price. The rest is the software, hardware engineering, and fabrication. When you see a price on a package of basic electronics (none of the technology in these sensors is truly novel), what that really tells you is how many customers the manufacturer anticipates. $100-$200 means “tens to hundreds of thousands, but not millions.”