Fluxus Ventures Technology Summary: indoor air quality sensors


By: Jon Bartelt, Partner at Fluxus Ventures

Why should you care about indoor air quality?  Throughout our everyday lives we encounter many different types of pollution, whether we are aware of it or not. One form of pollution that we encounter frequently, contaminants in the air outside, is often easy to identify. We see smog above a city, we smell vehicle exhaust while walking down the street, and we see dust, pollen, and dirt building up on our vehicles, our patios, or our windows.  Outdoor air pollution is indeed a serious problem, but we are generally aware of it, and our cities and governments work to address the issue (some more effectively than others, unfortunately).

That said, we spend roughly 90% of our time indoors, which means most of the air we breathe comes from inside buildings. Since most office buildings and many homes have HVAC systems, it is easy to assume that the conditioned air you breathe at work and at home is always clean and safe. However, several studies have shown that the quality of the air you breathe while indoors varies significantly from building to building and has significant effects on your health and your productivity while at the office.


The most common contaminants found in conditioned indoor air are small particles (PM2.5), volatile organic compounds (VOCs), and high levels of carbon dioxide (CO2). PM2.5 particles are particularly unhealthy because they can become stuck in your lungs when you breathe and can eventually enter your bloodstream and affect the circulatory system. As a result, exposure to these particles has been linked to higher levels of cardiovascular disease,[1] increased risk of respiratory issues and asthma,[2] and worsening lung function.[3] High levels of VOCs and CO2 in indoor air are less dangerous, but these contaminants been shown to significantly decrease worker productivity and increase negative symptoms such as allergies and headaches.[4] VOCs typically are a byproduct of building materials (e.g. paint, foam, carpet), cleaning products (e.g. air fresheners, disinfectants, dry cleaning), and certain activities (e.g. smoking, photocopying, carpet cleaning). Example VOCs include benzene, formaldehyde, and toluene, and these volatile chemicals are slowly released into the air and can build up in areas with poor ventilation. CO2 is a harmless gas at normal levels, but rooms with poor ventilation and many occupants can build up a high level of CO2, which can promote fatigue and headaches. Simply put, poor indoor air quality makes office workers less productive and less healthy.

Given the consequences, it is surprising that most people know nothing about the quality of the air inside their workplace and home! Fortunately, things are changing for the better. Several recent articles have shed light on the consequences of poor indoor air quality,[5] and green building certificates are increasing incorporating indoor air quality requirements.[6] Furthermore, several startup companies have released affordable consumer products that aim to assess the quality of indoor air. 

Which new devices monitor indoor air quality? Due to the rapidly decreasing cost of sensors and cloud-based software, entrepreneurs have been able to design indoor air quality monitors that cost less than $300. Previously, PM2.5 monitors and chemical sensors for VOC measurement cost several thousand dollars and were mostly relegated to academic or commercial use. The introduction of these new devices is exciting because building occupants can, for the first time, affordably monitor the quality of the air they are breathing in real time. We have compiled the following list of some recently developed indoor air quality monitors to show the options available (please note our list is not comprehensive and we are not endorsing any particular products):

Speck2.0 – measures humidity and PM2.5 levels, $199 

Speck2.0 – measures humidity and PM2.5 levels, $199 

AWAIR – measures temperature, humidity, CO2, VOCs, and PM2.5 levels, $199

AWAIR – measures temperature, humidity, CO2, VOCs, and PM2.5 levels, $199

Air Mentor – measures temperature, humidity, CO2, VOCs, and PM2.5 levels, $199

Air Mentor – measures temperature, humidity, CO2, VOCs, and PM2.5 levels, $199

uHoo - measures temperature, humidity, CO2, VOCs, PM2.5 levels, and ozone, $299

uHoo - measures temperature, humidity, CO2, VOCs, PM2.5 levels, and ozone, $299

Which device a user will find most useful will depend on a variety of factors including whether they want measurements to be displayed on the device or just in an app, how many sensors they want included, and which design they prefer. Furthermore, users will want to choose a device that provides their preferred data collection method, whether that is streaming data to the cloud, storing all past data for analysis, or simply providing real-time measurement values on the device. Having access to past data for analysis is particularly useful for verifying whether certain fixes/interventions had any effect on air quality.

Will these devices solve your air quality problems? Installing one of the aforementioned air quality monitors in your home or office will not by itself improve air quality. In order to fix issues with air quality, building occupants or managers must take specific actions. What the devices will do, however, is identify whether there is a problem with air quality and monitor quality over time to ensure that the air remains clean and safe. Real-time air quality monitoring can also be helpful in diagnosing pollution sources. As an example, the PM2.5 level in a home may spike when the air conditioner turns on, hinting at an issue in the HVAC system.

How can you improve indoor air quality? Examples of fixes/interventions that may be necessary to improve indoor air quality in commercial buildings include adding HEPA filters to HVAC systems, closing office windows when the outdoor air quality is poor, increasing HVAC ventilation rates, and ensuring fresh air intakes are far from outdoor pollution sources (e.g. car loading zones, busy roadways, diesel generators). Most of these fixes are relatively simple and inexpensive, but building managers have been shown to significantly overestimate the cost of these actions.[7] Furthermore, building managers are typically only incentivized to minimize building maintenance costs and maximize system uptime, so tenant productivity is generally not considered when making financial decisions (we believe this misalignment of incentives is a serious issue, but proposing solutions is beyond the scope of this article).

Researchers have shown that doubling the ventilation rate in an office building will generally cost <$0.20 per square foot per year[8] and that increasing ventilation rates is an easy way to improve air quality.[9] This additional cost is more than paid for by the added productivity experienced by workers in buildings with clean air. Increasing the productivity of the employees in an office by 5% (several studies have shown clean air provides larger gains than this!) unlocks an extra $20 per square foot in productivity benefits each year (assuming 5 employees per 1,000 square foot of office space).[10] Additional benefits of offices with clean air include fewer employee sick days and a healthier, happier workforce. As a result, company executives and managers should be motivated to ensure that building managers have the tools and data needed to monitor and improve indoor air quality.

In primary residences, the most effective way to combat indoor air pollution is to avoid exposure to pollution sources (yes, it sounds obvious). Although not always possible, it is best to avoid purchasing/renting a residence that is within 500 feet of a major roadway because vehicles release PM2.5 particles and noxious fumes in their exhaust. Studies have shown that living near busy roadways increases the likelihood of developing several adverse health outcomes including asthma, heart attacks, and lung cancer.[11] Other mitigation techniques include regularly replacing the air filter on vacuum cleaners and HVAC systems, using harsh cleaning chemicals sparingly, and closing windows when the air quality outdoors is poor. One of the easiest and most important ways to avoid indoor air pollution is to always turn on the above range exhaust hood when cooking and to regularly replace the air filter in hoods that use filters.[12] Searing and frying food releases fine particles and unhealthy gases into the air, and an exhaust hood is the best way to prevent these contaminants from circulating through your house. In addition to these preventative methods, utilizing an indoor air purifier may actively clean indoor air to some degree. However, these devices are often expensive (>$500) and multiple devices may be needed to clean all of the air in a home. 

Taken together these findings show that indoor air quality is of paramount importance. Given that the cost of air quality monitors has decreased significantly in recent years, there are no longer excuses for ignoring this issue. Furthermore, we expect more innovation in the air purifier and air filter space as entrepreneurs continue to tackle this problem. These hardware innovations, in addition to innovations in analytics platforms and data sharing, should help us collectively improve the air we breathe. We will all be more productive and healthier if we pay attention to this important issue!



[1] J Thorac Dis. 2016, 8: E8–E19

[2] Annu. Rev. Public Health. 1994, 15:107-32

[3] Environ Sci Pollut Res Int. 2016, 23: 23892–23901

[4] Int J Environ Res Public Health. 2015, 12:14709-22

[5] http://www.newsweek.com/2016/06/10/indoor-air-pollution-revolution-465531.html, http://fortune.com/2016/03/15/office-air-quality-productivity/, https://hbr.org/2017/03/research-stale-office-air-is-making-you-less-productive, http://www.latimes.com/projects/la-me-freeway-pollution/

[6] Building and Environment. 2015, 92:10-19

[7] Indoor Air 2016, 26:318–330

[8] Assuming 5 occupants per 1,000 square feet

[9] Int J Environ Res Public Health. 2015, 12:14709-22

[10] Assuming a baseline employee salary of $80,000

[11] http://www.latimes.com/projects/la-me-freeway-pollution/

[12] http://www.nytimes.com/2010/04/01/garden/01fix.html