Modern Houses & Indoor Air Quality 🏡

One will think that the more modern the house, the better the indoor air quality. However, that’s not always the truth as recently I discovered that many houses have inadequate appliances that will create harmful air pollutants and some of them will falsely mitigate contaminants by creating a false sense of remediation.

Example #1

Gas cooktops are a must according to good chefs as the pans are able to heat immediately and you have more control of the heat. That’s not true as the new induction cook tops are able to heat the bottom of the pans as fast without releasing harmful pollutants like Nitrogen dioxide.

Gas stoves, especially when unvented, can be the number one source of indoor air pollution. According to new research, gas cooking produces about twice PM2.5 as electric cooktops; including nitrogen dioxide (NO2), carbon monoxide (CO), and formaldehyde (CH2O). 

Example #2

Hoods, extractors or over-the-range microwaves “with” exhaust are important while cooking. However, the over-range microwaves that come with an extractor end up reticulating air indoors without proper filtration.

Most houses in the US have these false products that give the sense of remediation but they actually contribute to indoor air pollution. Look at the holes this aluminum filter has! These products are designed to trick customers and spend electricity without any measurable results. Shame on the companies that sell them!

Example #3

Once more, most gas heaters, which are installed indoors without any proper ventilation, result in more unnecessary indoor air pollution. They release the same pollutants as the gas stoves because the combustion of the “natural” gas, which is a fossil fuel, creates all of the above pollutants.


Although my cooktop doesn’t use gas, particulate matter is also released when we cook. I managed to mitigate the pollution that comes out of the pots while cooking with a portable air purifier (AirBubbl by Rensair) which was able to fit above the microwave and capture on the HEPA filter most of the particles by easing the air I breathe indoors.

Finally, I keep windows open when possible and the bathroom extractor on in order to dilute the indoor air with outdoor air (when the ambient air is clean). CO2 and VOCs drop significantly with this technique and PMs are managed well.

It is hard to make drastic changes to an apartment when living on rent, but there are a few techniques that will help us remove pollutants from the indoor air. Next, I will have to buy a high CADR number indoor air purifier with a good HEPA filter.

The Truth about Indoor Air Quality

Not lots of people are ready to accept the truth or understand it. We dismiss important information when it is not visible “out of sight, out of mind” and we get influenced when something is shiny and pretty.


Poor air quality won’t kill you (at least not immediately and depending on the pollutants), but do you want to be an average employee, athlete, parent, student, or the best? Do you want your employees to work in mediocre conditions and perform poorly, or do you want them to be vibrant and productive?

Excellent indoor air quality will boost the performance of all. The main environmental parameters you must consider addressing are four, Particulate Matter (PM2.5), Carbon Dioxide (CO2), Temperatures, and Humidity. I haven’t included VOCs because poor ventilation and high CO2 levels will result in high VOC levels, so I made things easier.


Air pollution is not easily understood by most people mainly because it is invisible. No one is going to drink a glass of water if the water is dirty but how many times have you had to breathe second-hand smoke, vehicle fumes, or wood-burning smoke! I will say with certainty there were many times and you don’t even worry or remember about it.

The respiratory system isn’t designed to deal with fine particulates and other pollutants. The gastrointestinal system, where solids and liquids get digested, can deal with contaminants because it can get rid of them through the two avenues designed by nature. Sure drinking or eating extremely spoiled food and drinks can lead to deadly diarrhea. However, the respiratory system cannot do something similar and pollutants get accumulated inside the lungs. The smallest pollutants like PM1.0 and gases are distributed through blood even to the brain.

Sure, you can cough, but once particles are inside us they are stuck around the walls because of the fluids. Here is an example of an adult male who was a non-smoker and his lungs are black because of the indoor and ambient pollution. He donated his body to science, and now people can see “him” at the museum of Granada in Spain.

I don’t want to repeat myself and tell you that you spend 86.9%NHAPS of your time indoors, but it’s a fact!

Air is the most important element because without it you only have 3 minutes to live. You literally remove years from your life when pollution is inhaled.

Finally, I believe it is time for researcher to look into the size distribution of the particles rather than generic PM2.5 values that can represent many potential size distributions.

Particulate Matter (PM2.5) Mega Guide

In this article, you will find information about everything related to particulate matter. I will focus on PM2.5 as I believe it is the most universal indicator of air quality. Almost all scientific studies concentrate their attention to PM2.5 because there is a substantial availability of monitors/sensors. Some extracts were taken from my book See The Air – PROOF THAT AIR POLLUTION KILLS.

1) What is PM2.5?

Scientific explanation: PM2.5 is a mass concentration on basis of a separation curve, where the 50% value is at 2.5μm aerodynamic diameter. More precisely, the weighting function is much steeper (100% weighting <0.5μm, to 0% weighting> 3.5μm and 50% weighting at approximately 2.5μm). PM2.5 pollution can only be seen with an electron microscope.

Plain English explanation: PM2.5 referees to fine particles with a size of or less than 2.5μm (aka micron). By the way, soot, aerosols, dust, BC are other common terms to call particle pollution.

2) What is PM2.5 made of?

It is hard to determine a specific chemical composition, however, here is a list of all the chemicals that might be found in a single particle. Polycyclic aromatic hydrocarbons (naphthalene, acenaphthylene acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a) pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, and indene), metals (Al, Si, P, S, CI, K, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Pb, Ca), others.

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Air Quality Monitors – Comparison List 2022 Q2

The famous list with all the available indoor air quality monitors is finally updated. In this version there are two tabs. Air quality monitors for consumers (B2C) and for businesses (B2B). As always, I stay away from knockoffs and cheap products. An air quality monitor needs to function properly for 5 to 10 years depending the sensors − gas sensors tend to have a shorter lifespan.


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Spring Is Around the Corner & Allergies too

I love spring as it marks the return of warm weather, outdoor activities, the blossom of flowers, and life in general. However, pollen becomes abundant everywhere there are plants and trees, as a result, the flare of allergy-related health issues too. I am allergic to some kind of pollen and although I can manage it without medication, some people are suffering to a greater extend and they need better ways to mitigate pollen out of their immediate environment.

Unfortunately, on earth, there are only a few special Air Quality monitors that can measure and classify pollen. Satellites also track the progress of pollen but do you know where to find this kind of information? I bet no, for this reason, I will tell you in a bit.

Remember, the first step is always quantifying the pollutants/allergens (pollen in this case) before mitigating them from indoor spaces. The reason is simple, once we have the proper information, we can take better decisions. For example, should I exercise outdoors today or go outside for some errands or is this the right moment to ventilate my house?

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Office Study – Tapping Into The Real World Air Quality Data

Nowadays, it is a privilege to have access to a real indoor environment where you can measure and quantify indoor environmental quality (IEQ). It is not an easy task because most companies keep AQ data private, and we totally respect that. However, sometimes tapping into the real world data is fundamental in order to understand the conditions white color employees and employers work in an effort to improve work conditions and productivity.

The owner of the building and the office granted me access to installing the Atmocube IAQ monitor for two months, in order to figure out what improvements shall apply in their effort to mitigate covid19, improve working conditions and boost productivity. The office is located in Almeria, Spain which is a coastal city.

They don’t have any mechanical ventilation systems, so the indoor conditions were subject to their human actions and whether they opened the windows/doors or not.

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AirGradient DIY Indoor & Outdoor Air Quality Monitor

Countless times I have mentioned that we need to monitor indoor and outdoor air quality. This is an essential step in order to have a holistic approach to air pollution that surrounds us in both environments. Unfortunately, not everybody can afford to buy two monitors but thanks to the community and AirGradient there are two DIY solutions that can help us monitor the air quality quite accurately and of course, manage the air we breathe better.

AirGradient’s DIY solution is more appealing than the competition for many reasons. First of all, you can buy directly the DIY Kit with all the electronic components from them including the PCB. The PCB is the board where we will deploy all the sensors, WiFi module, and display. That is a huge benefit because you don’t have to search on the internet and purchase the components one by one. The well-designed PCB will also help us keep the monitor neat and small without unnecessary cables. Secondly, Air Gradient’s DIY AQ Monitor is very customizable allowing us to build an indoor monitor with an NDIR CO2 sensor but another one without a CO2 sensor or display for the outdoor environment. If you don’t want temperature/humidity sensors you can easily omit them too, but I highly recommend them. Moreover, there is software support as a community of passionate people have been improving the firmware constantly. Finally, the solution comes with a web dashboard where you can manage all the monitors and take advantage of the histograms and tools like the alerts.

Additionally, the devices which are connected to the cloud and the dashboard can broadcast the measurements back to a separate display (Viewport) which allows us to see the air quality indoors and outdoors like in the example below. Isn’t that very cool?

It has been a long time since I soldered something, so I was very happy to build the monitor. I built two monitors by following the fairly easy instruction here. There is also a video with the instructions here by Jeff Geerling.

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Review: IKEA VINDRIKTNING Air Quality Monitor

In 2021, IKEA made available an indoor air quality monitor, which is very very affordable. I bought one because I was curious to answer some basic questions like how did they manage to build and sell a particulate matter sensor that costs only 14€ or US$12 but also how smart and reliable is it in relation to other monitors.

IKEA is obsessed with naming all their products with Swedish words, so the AQ monitor VINDRIKTNING (which I can’t pronounce) translates as Wind Direction. Obviously, they don’t aim to create names memorable to people’s minds.

Let me share a story with you. Long before covid19 (2018 if I remember well) I and a company I worked for, decided to pitch IKEA into building an AQ monitor as I saw their interest in air quality because they designed some photocatalyst curtains that neutralized VOCs back then. Unfortunately, they turned us down, but I think we planted a seed into them. Long story short in 2021 they released the VINDRIKTNING.


  • Particulate Matter Sensor Cubic Sensor PM1006K
  • 1 Green / 1 Yellow / 1 Red LED
  • USB-C connector
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In & Out – Airthings & Airly

Countless times, I have said that it is very important to monitor our indoor air quality side by side with the outdoor air quality. A collaboration between Airthings and Airly brought the best of both worlds, ambient air quality and indoor air quality monitoring in one place. Unfortunately, this solution is available only to the business customers but we can always hope that the demand will drive the feature to the consumer clients as well.

Why in & out AQ monitoring is important?

Our indoor air quality depends on many factors like building material, furniture, and indoor activities (cooking in a home or printing documents in an office, the perfumes people wear, etc). All of these factors will determine indoor air quality from the inside but indoor air quality is subject to outdoor conditions too. Vehicle traffic, marine traffic (in case you live near a port), wood-burning, industrial activities in the area, and wildfires are some of the reasons that will affect indoor air quality as buildings need to breathe or ventilate if you want.

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Back Indoors – Indoor Air Quality is still a thing, here is why!

Autumn and Winter are almost here for the Northern Hemisphere which means a vast majority of the population is going to leave terraces and other open outdoor spaces for indoor spaces (offices, classrooms, homes, indoor restaurants, etc). Covid-19 is still present, but most importantly, we are going to breathe lots of indoor air. We need to take control of the air we breathe as indoors is much easier to diminish the quantity of pollutants we inhale than been outside.

Covid-19 has ruined the lives of many people, personally, I believe that it is very easy to combat the spread of the virus in enclosed spaces, but we need to follow the rules of proper ventilation and purification combined. Scientists have developed various kinds of technologies that can capture pollutants and pathogens. I don’t want to focus very much on the pandemic rather than how important is to breathe clean and fresh air indoors for so many other reasons.

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