KBO-PCOB pleit voor laagdrempeliger testen en ventilatiecheck in verpleeghuizen. Dit om de verspreiding van Covid-19 tegen te gaan. Wij denken dat het belangrijk is om continue luchtvochtigheid, temperatuur, volatiele deeltjes als CO2 te meten.


“Daarnaast worden niet alleen binnen scholen maar ook binnen verpleeghuizen vraagtekens gezet bij de betrouwbaarheid van de ventilatiesystemen als het gaat om verspreiding van aerosolen via zo’n systeem. KBO-PCOB dringt er daarom op aan dat ventilatiesystemen bij verpleeghuizen voor 1 oktober gecheckt worden door uitbreiding van de taken van het Landelijk Coördinatieteam Ventilatie op Scholen. Vanderkaa:“In verpleeghuizen verblijven kwetsbare mensen, daar moet de luchtkwaliteit goed zijn. Het mag niet zo zijn dat bewoners gevaar lopen door ondeugdelijke ventilatiesystemen.”” (KBO-PCOB website)

Belang luchtkwaliteit: continue check

Wij denken dat het wenselijk is dat de luchtkwaliteit continue gecheckt wordt. Niet alleen vanwege Covid-19. Ook om te zorgen dat de luchtkwaliteit goed is vanwege de kwetsbaarheid van oudere mensen.  Om zo de verspreiding van andere virussen zo goed mogelijk tegen te gaan. Daarnaast kan een slecht binnenklimaat leiden tot klachten als niezen, hoofdpijn, duizeligheid. Ook kunnen allergieën en astma worden verergerd. Een oplossing als Airmex meet zowel luchtvochtigheid, temperatuur, volatiele deeltjes als CO2.

More than half (51 percent) of all elementary school in the Netherlands sent one or more classes home last week because of Covid 19.

“The AVS estimates that nearly 220,000 elementary school students were quarantined at home, out of a total of about 1.6 million students. According to the poll, 1.3 percent of elementary schools were forced to close completely because of corona attacks ” (Metro Nieuws)

Staffing shortage

Metro continues: “According to President Petra van Haren, the pressure is on school leaders. ‘They are constantly looking for substitutes to prevent children from having to go home,” she says. Of the school leaders who participated in the survey, 60 percent had to use substitutes last week. “Because of the staffing shortage, that’s not easy,’ Van Haren says.”

1 Child infected, whole class at home

If in a class a child or teacher is infected with the coronavirus, the entire class must go home. For at least five days as a precaution. Unless they work in small groups that are not close to each other. In most elementary schools, however, this does not happen. Many schools find it practically unworkable. Those who get tested five days after contact with the infected child and get a negative result may return to school. Children who do not test may return to school only after ten days, provided they have no symptoms.

How sensors help

Sensors like the Airmex help monitor air quality to ensure that the Covid 19 virus is as inactive as possible. And to ensure that temperature and humidity levels are optimal for a pleasant stay and an optimal environment for performance. They also measure CO2. CO2 is another important air quality parameter.

For many, Covid-19 was an eye-opener for the importance of indoor air quality. One of the most important pollutants indoors is Carbon Dioxide (CO2). Children spend a large portion of the day at school. Research shows that there are high levels of CO2 in many classrooms. Those high CO2 levels affect the sense of wellbeing, and even worse: school grades.

CO2 levels in school too high

The Western Cooling Efficiency Center (UC Davis ) shows: “Research from around the world shows there are high CO2 levels in many classrooms. For example, in a 2019 study, researchers found that about 85% of 94 recently installed HVAC systems in California K-12 classrooms did not provide adequate ventilation.”They investigated 104 classrooms in California. 85% did not have proper ventilation, which means increased levels of CO2.

In indoor testing between 2010 and 2015, 43% of Toronto schools had a CO2 concentration above 1000 ppm.

Why does the last hour always take ages?

bored child classroom school high co2 levels airmex

After sitting the whole day at school, the last hour seems to take ages. Always getting a headache. You can’t concentrate and think properly. Probably the cause it isn’t the teacher. It’s you, the students.

Students and the teacher breathe oxygen into the lungs as energy. The oxygen sticks to red blood cells and is transported to organs and muscles, so your heart can pump, you can think with your brain and contract your muscles. This ‘burning’ process of oxygen turns into carbon dioxide (CO2) and water vapor, which are released back into the environment.

When the ventilation is poor, the ‘used’ air will not dilute enough with ‘new’, fresh air from outside. So, especially with many people in a closed room (like a class-room) and the ventilation is poor, the oxygen in this room gets more and more replaced by CO2.

CO2 itself is not toxic. In fact, it’s a natural part of the atmosphere. It’s the fact that it’s replacing the oxygen concentration because a high concentration of CO2 is toxic. (That’s why CO2 is called an ‘asphyxiant gas’:  a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathable air.)

How CO2 levels affect school results

Due to the fact that the student inhales less oxygen, less oxygen goes to the brains. If there’s too much CO2, students may find it hard to pay attention to the teacher. Or concentrate on tests. Or stay awake at all. Besides, high levels of CO2 may affect the ability to make decisions. So, without even realizing yourself, high CO2 can damage your productivity and your school results. Besides, when we think of gasses, we think smell will warn us. However, CO2 is odourless.

CO2 might also cause physically complaints:

  • Headache
  • Feeling dizzy or nauseous
  • Tired
  • Trouble breathing
  • Worsen asthma symptoms, allergies and lung health

You yourself might feel complaints, while the student next to you doesn’t feel anything. How you react, depends on several factors – such as: your own health, heredity, personal habits as smoking and drinking, use of medicine, previous exposure to chemicals.

What are high CO2 Levels?

As said, CO2 is a gas that is a natural part of the air. CO2 is measured in so-called parts per million (ppm). Outside, the normal level is about 400ppm. Otherwise said: per 1 million parts in the air, 400 of them consists of carbon dioxide. Before the industrial revolution, this level was about 280 ppm.

In general, occupied rooms with good ventilation have 400 – 1,000ppm. However, from 800 ppm, people may begin to suffer, maybe without knowing themselves.

From 1,000 to 2,000 ppm, people get complaints of drowsiness and poor air. When the level is between 2,000 to 5,000 ppm: complaints of headaches and sleepiness. The air becomes stale, stagnant and stuffy. As a consequence, people have lower concentration and loss of attention. An increased heart rate and slight nausea may also be the case.

From more than 5,000 ppm, the air becomes toxic and more serious effects can occur.

Common HVAC Issues resulting in high CO2 levels

In modern times, schools and other buildings are built with comfort in mind: to create a comfortable, warm space, thanks to isolation and… However, this comfort may come with a downside. Because a room is too closed from the outside world, this may result in the lack of replacing the air inside with fresh air from outside.

In the California study, 85% of the classrooms did not provide adequate ventilation. ‘“We were shocked,” said Wanyu Rengie Chan, one of the lead researchers of the study, “We were not expecting it.”’ They were shocked, because it involved classrooms with newly installed HVAC.

What are HVAC issues, causing high CO2 levels?

  • Problems with installation of HVAC systems
  • Incorrect HVAC systems purchased
  • Incorrect controls and thermostats
  • No follow-up testing after installation
  • Poorly-maintained filters

(Source: Ventilation Rates in California Classrooms study)

CO2 monitoring helps

Children spend many hours indoors at school. Therefore, it is important to have a good indoor air quality. For the feeling of well-being for the children and teacher, but also for the children’s grades. You can measure the CO2 with a CO2 meter, or a sensor which combines the monitoring of CO2 with temperature, humidity and Volatile Organic Compounds, for instance ASN’s Covid-AIRMEX.

Advanced Solutions Nederland’s AIRMEX employs the Nordic Thingy:52 to provide easy-to-use environmental sensors and wireless connectivity for pandemic management

Nordic Semiconductor today announces that Amersfoort, Netherlands-based, Advanced Solutions Nederland (ASN), an IoT and Industrial IoT (IIoT) sensor technology company, has selected the Nordic Thingy:52 Bluetooth® 5.2/Bluetooth Low Energy (Bluetooth LE) compact multisensor prototyping platform to provide the wireless connectivity and processing power for its ‘AIRMEX’ indoor environmental monitoring solution. AIRMEX is an AI-powered temperature, humidity, CO2, and TVOC (Total Volatile Organic Compounds) sensor platform that enables, for example, workplaces, schools, restaurants, and places of worship to monitor and regulate indoor environmental conditions to minimize the risk of the airborne spread of SARS-CoV-2, the virus that causes Covid-19, as well as promote overall healthy living and working conditions for occupants.

This article is retrieved from Nordic Semiconductor: original publication, 04Mar 2021 Oslo, Norway)

Recommendations for air-quality improvement

The ceiling- or wall-mounted device employs the Nordic Thingy:52’s integrated humidity, temperature and gas sensors to provide continuous, near real time monitoring of environmental air quality. Running ASN’s ‘Chameleon’ AI algorithmic application software—developed and ‘trained’ to promote indoor air conditions that specifically minimize the risk of the spread of Covid-19—the Nordic Thingy:52’s powerful 64MHz, 32-bit Arm® Cortex® M4F processor with floating point unit (FPU), allows the solution to process the data from all four sensor. The applications software does more than simply measure and display temperature and humidity readings, rather it provides real-time updates and recommendations for air quality improvement.

The Nordic Thingy:52 integrates many useful sensors which along with its Bluetooth LE connectivity provides a cost-sensitive solution

Dr Sanjeev Sarpal, ASN

The data is relayed to a Bluetooth 4.0 (and later) smartphone, where from the partner ‘Covid-AIRMEX’ Android app, the user is provided with immediate feedback on overall air quality and recommendations on how to improve the environmental conditions. For example, “increase dehumidifier settings” to reduce humidity, or “very high gas levels present” to indicate inadequate ventilation. In the absence of a smartphone, AIRMEX has a multi-coloured LED indicator to provide users with an immediate overview of current environmental conditions.

AIRMEX uses a standard 1400mAh Li-ion battery to provide approximately six weeks battery life in standard operation, thanks in part to the ultra-low power characteristics of Nordic’s nRF52832 System-on-Chip (SoC) at the heart of the Nordic Thingy:52. The nRF52832 has been engineered to minimize power consumption with a fully-automatic power management system that reduces power consumption by up to 80 percent compared with the nRF51 Series. 

Multisensor prototyping platform

The Nordic Thingy:52 is a compact multisensor prototyping platform designed to help wireless IoT sensor projects get off the ground quickly. The product is a fully tested and working wireless sensor platform that can be used by a developer with no high-level development tools or firmware coding expertise to rapidly design wireless IoT devices and associated mobile device and Internet apps. The Nordic Thingy:52 is based on the nRF52832 SoC. The SoC features a 32-bit, 64MHz Arm® Cortex™ M4 processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5.2, ANT™, and proprietary 2.4GHz RF protocol software) featuring -96dB RX sensitivity, and 512kB Flash memory and 64kB RAM. The SoC runs Nordic’s S132 SoftDevice—a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications—it can support up to 20 concurrent connections in a variety of Bluetooth LE role combinations.

“The Nordic Thingy:52 integrates many useful sensors which along with its Bluetooth LE connectivity provides a cost-sensitive solution,” says Dr Sanjeev Sarpal, Director AI Data Algorithms & Analytics at ASN. “The well written firmware libraries also helped our developers get up and running in a fraction of the time rather than starting a development from scratch, while the reference designs and good documentation were equally an important consideration in selecting the solution.”

Since Covid-19, there is even more attention for indoor air quality. It might be possible that poor ventilation may contribute to the spread of the coronavirus. In any case, some contaminations are already known to decrease indoor air quality. Poor Humidity, Temperature, CO2 and TVOC conditions may be the cause. It influences productivity, leads to less sense of comfortability and well-being and can cause sickness. Beat poor indoor Air Quality with data science.

Indoor concentration of pollution often 2 to 5 times higher than outdoor

Did you ever wonder where you are most exposed to air pollution? Somewhere outside, you say? Wrong, you breath the most polluted air… indoors! Research shows, that people spend 90% of their time indoors. Isolation and modern heating have brought us comfy, warm indoor environments: home, work, recreation, etc., with no cold air coming from under the doors or through windows. However, in many buildings there is a downside. With the tightly enclosed indoor environments, pollution caused indoors or coming from outside has no opportunity to mingle with fresh air. For viruses, heat and certain levels of humidity are perfect environments to stay active.

Pollution may lead to:

  • Irritation of the throat, nose and eyes, such as a dry throat
  • Headaches, dizziness, and fatigue
  • Respiratory diseases, heart disease, and cancer


Besides, the Covid-19 virus is spreading. Since Covid-19, there is a lot of attention for indoor door quality. Besides social distancing, wearing a mask and washing your hands, good ventilation is one of the measures to reduce the risk of infection indoors.

CO2 and TVOC measurement for well-being and productivity

Indoor air quality is depending on… inside and outside factors… Besides temperature and humidity, 2 other factors for indoor air quality are CO2 (Carbon Dioxide) and TVOC (Total Volatile Organic Compounds).

CO2 originates when people breathe, sweat and in all other occasions where there is a burning process involved. CO2 concentration has to remains less than 800 PPM. At higher concentrations people begin to suffer.

Besides, many substances are also source of contamination like cleaning products, paints, varnishes, furniture and glues. These are called Volatile Organic Compounds (VOC’s). Immediate complaints may be symptoms headaches, eye, nose and throat irritation and bad odors. Long term exposure may lead in large doses can damage liver, nervous systems and kidneys.

The impaction of the combination of CO2 and TVOC is even larger. A study shows: “On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day.” 

Data Science helps you to maintain healthy and productive air quality

Temperature and Ventilation are more important than ever. Regulate your temperature to obtain a comfortable and healthy environment. Replace bad air with fresh air from outside. By ventilation or just by opening a window.

When you’re busy, keeping an eye on working conditions may be easily ignored. Sensors which measure temperature and humidity like the Airmex help you to maintain your indoor air quality such, that the risk of spreading the viruses is as least as possible They also help you to keep a comfortable, healthy and productive environment. It warns you on an app when you should adjust your room temperature or when you should ventilate. Those signals are based on data science and based on guidelines as the ASHRAE Standard 55 – Thermal Environmental conditions for Human Occupancy.

Find out how the Airmex can help you.

You have probably experienced a ‘sick building’ yourself. You may not feel well in a room or building, such as irritated eyes or nose. Without knowing exactly where this feeling comes from. Or you experience that you suddenly feel better when you leave that room or building. The term “sick building syndrome” (SBS) is first used in the 1970s. It describes a situation in which reported symptoms among a population of building occupants can be temporally associated with their presence in that building. Typically, though not always, the structure is an office building.

Symptoms of Sick Building Syndrom (SBS)

In short: more co-workers experience the same complaints when they are in the building or in the same parts of a building. Most of the times, complaints disappear or lessen when people leave those buildings or parts.

Symptoms of a Sick Building Syndrom can include:

  • eye, nose and throat irritation (irritation of mucous membranes)
  • lethargy or fatigue
  • headache, dizziness, nausea
  • inability to concentrate
  • sensitivity to odors
  • general malaise-complaints

Indication that the complaints are caused by Sick Building Syndrome are:

  • Are problems temporally related to time spent in a particular building or part of a building?
  • Do symptoms resolve when the individual is not in the building?
  • Do symptoms recur seasonally (heating, cooling)?
  • Have co-workers, peers noted similar complaints?

Difference between Sick Building Syndrome and ‘building related illness’

It is important to distinguish the ‘Sick Building Syndrome’ from building related illness. Building related illness means that symptoms of illness can be directly related to specific airborne building contaminants. Examples are Legionnaire’s Disease or hypersensitivity pneumonitis.

What causes sick building syndrome?

The EPA distinguishes 4 causes of or contributing factors for sick building syndrome (Indoor Air Facts No. 4 (revised) Sick Building Syndrome):

  • Inadequate ventilation
  • Chemical contaminants from indoor sources
  • Chemical contaminants from outdoor sources
  • Biological contaminants

Inadequate ventilation

Due to the fact that outdoor air ventilation is inadequate to maintain the health and comfort of the people inside the people. Another reason for inadequate ventilation may occur if heating, ventilation and air condition (HVAC) systems do not effectively distribute air to people inside the building

Chemical contaminants from indoor sources

Most of the indoor pollution comes from sources inside the building. For example: adhesives, carpeting, upholstery, manufactured wood product, copy machines, pesticides and cleaning products may emit volatile organic compounds (VOCs), including formaldehyde. Tobacco smoke may also be a source, if smoking is still allowed inside the building. Another source may be combustion products, due to unvented gas and kerosene heaters, gas stoves, woodstoves and fireplace

Chemical contaminants from outdoor sources

For example, motor vehicle exhausts which enters the building

Biological contaminants

Examples are bacteria, molds, pollen, viruses and animal droppings

It’s possible that the underlying causes of the above-mentioned factors are:

  • Poor ventilation, due to poor design, maintenance or operation. The ventilation itself can be a source of irritants.  Besides, interior redesign such as rearrangement of offices may cause inefficient functioning of the systems.
  • These elements may act in combination. Where some pollutants themselves are at a very low level, the way they react on each other may cause health effects
  • Elements may supplement other complaints such as inadequate temperature, humidity, or lighting. High humidity may contribute to biological pollutant problems. On the other side, levels below 20 or 30 percent may heighten the effects of mucosal irritants and may be irritating itself
  • Other factors may also play a role, such as stress, noise, insufficient light.

Solutions like the Airmex can help you to create a safe and healthy environment for work, meeting and living. It monitors your air quality and alarms you when the air quality has dropped below acceptable levels

Vanaf 1 maart gaan middelbare scholen weer open na de lockdown vanwege Covid-19. Het basisonderwijs en de kinderopvang zijn vanaf 8 februari open gegaan. Echter: nog niet alle scholen blijken te voldoen aan de richtlijnen voor ventilatie. Dit terwijl goed ventilatie mogelijk de verspreiding van het coronavirus verminderd. En zeker draagt goede ventilatie bij tot het welzijn en is gezonde lucht beter voor leerprestaties

Scholen gaan weer open

Het basisonderwijs en de kinderopvang is vanaf 8 februari weer open gegaan. Vanaf maandag 1 maart gaan de middelbare scholen en mbo-instellingen voor alle leerlingen weer open: op 23 februari heeft het kabinet besloten dat alle leerlingen en studenten minimaal 1 dag per week fysiek naar school gaan. Dit om meer perspectief aan jongeren te bieden: fysiek onderwijs draagt bij aan het welzijn en is beter voor leerprestaties.

Ventilatie schoolgebouwen: 777 schoolgebouwen voldoen nog niet

Het Landelijk Coördinatieteam Ventilatie heeft onderzoek uitgevoerd naar alle scholen (primair en voortgezet onderwijs) in hoeverre scholen voldoen aan de ventilatienormen. Hiervoor heeft zij in september een vragenlijst verstuurd.

Uit dit onderzoek blijkt dat nog niet alle schoolgebouwen aan de wettelijke normen voor ventilatie voldoen:

Onderzoek kwaliteit binnenlucht. De volledige vraag luidt: “Heeft er in het schoolgebouw per ventilatiesysteem een onderzoek plaatsgevonden naar de kwaliteit van de binnenlucht op basis van de capaciteit voor luchtverversing, een permanente CO₂-meting, of de indicatieve meetmethode? Voldoet het schoolgebouw aan de normen die voortkomen uit het Bouwbesluit en aanvullende richtlijnen?”

  • In september 2020 is door 7340 ingevuld. Uitgaande van 9331 is dit 79% van het totaal aantal scholen.
  • 777 scholen geven aan dat zij niet voldoen aan de richtlijnen. Dit is 11% van de totale respons van 7137 schoolgebouwen. Oftewel 22% van de scholen aangeven dat het onderzoek heeft plaats gevonden. Hier zijn technische aanpassingen nodig.
  • 2952 scholen geven aan dat zij voldoen aan de richtlijnen. Dit is 78% van de scholen waarbij het onderzoek heeft plaats gevonden.  Hierbij wordt wel bij 325 metingen opgemerkt dat men nu voldoet, maar zich zorgen maakt over de wintermaanden.
  • 2678 scholen geven aan op korte termijn onderzoek zullen uitvoeren, bijvoorbeeld wanneer er CO2 meters beschikbaar zijn
  • 730 scholen geven aan dat ze het onderzoek niet kunnen uitvoeren. “Als redenen om het onderzoek niet uit te voeren geeft men voor 128 gebouwen het onderzoek ‘later, op een nog niet bekend tijdstip uit te voeren’ en wordt voor 155 gebouwen opgemerkt dat geen CO₂-meters beschikbaar zijn.”

Bij het niet hebben kunnen uitvoeren speelt ook mee dat het onderzoek op korte termijn heeft plaats gevonden: sommige scholen hadden geen technici beschikbaar of gaven het onderzoek geen voorrang.

Scholen blijven open als ventilatie niet goed is

Schoolgebouwen moeten voldoen aan de wettelijke normen voor een gezond binnenklimaat conform het Bouwbesluit en de aanvullende richtlijnen.  Hiervoor stelt het kabinet € 360 miljoen beschikbaar om scholen te helpen de ventilatie op orde te krijgen.

Coronavirus en ventilatie

Op de site van de Rijksoverheid:

“Ventilatie en verspreiding van het coronavirus

  • Overdracht van het virus vindt vooral plaats bij verspreiding van grote druppels, via bijvoorbeeld hoesten en niezen, aldus het RIVM.
  • Het is op dit moment onduidelijk of kleine druppels, de zogenaamde aerosolen, een relevante rol spelen bij de overdracht van het virus. 
  • Ventileren en luchten helpen om luchtweginfecties te beperken.
  • Het RIVM adviseert in ieder geval de bestaande regelgeving en richtlijnen op het gebied van ventilatie en luchten te volgen. Dat geldt ook voor scholen. Bovendien leren leerlingen het beste in een prettige omgeving met gezonde lucht.
  • Het is onbekend in welke mate ventilatie helpt om de verspreiding van het virus daadwerkelijk tegen te gaan.”

Belang van ventilatie op welbevinden en leerprestaties

Sowieso is het coronavirus niet de enige reden voor ventileren:

  • Ventilatie kan helpen gezondheidsklachten als hoofdpijn te verminderen
  • Leerlingen leren het beste in een prettige omgeving met schone lucht. 

Het advies van de GGD is dan ook om scholen niet te sluiten bij onvoldoende ventilatie. Ook het kabinet noemt het belang van fysiek onderwijs voor het welzijn en leerpresaties in haar besluit om middelbare scholen en mbo-instellingen weer te openen, ondanks stijgende covid-19 aantallen.

Scholen die niet aan de normen voldoen, krijgen hierover nu al advies van de GGD, de arbodienst en Kenniscentrum Ruimte OK. Ook kunnen scholen gebruik maken van de handleiding die het Coördinatieteam heeft opgesteld. Zoals nemen van maatregelen als het plaatsen van roosters en het aanvullend luchten in pauzes.

Oplossingen als de Airmex kunnen helpen om de luchtkwaliteit in een schoolgebouw te bewaken door niet alleen CO2, maar ook temperatuur, luchtvochtigheid en volatiele deeltjes te meten. Dit voor een gezonde en prettige leeromgeving te creëren.

The most basic indication of indoor air quality is its temperature: you immediately sense if it’s ‘too hot’ or ‘too cold’. Temperature is important for indoor air quality:

  • Temperature and sense of well-being
  • Humidity
  • Spreading of Covid-19 and other viruses

Temperature and sense of well-being

The most basic indication of indoor air quality is its temperature: you immediately sense if it’s ‘too hot’ or ‘too cold’. And it immediately affects your sense of well-being. Extreme heat is a serious risk for your health ((Healy 2003, Kosatsky 2005). Besides, high temperatures can cause insufficient humidity (Reinikainen and Jaakkola, 2001).

How does Temperature Affect the Spread of Viruses

Since Covid-19, there is more attention for the strong influence of temperature on the spread and activity of viruses. Viruses that cause respiratory infections often occur in the winter. This may be caused due to reduced resistance of the so called ‘mucous membranes’ in the nose when cold air is inhaled (Frank van Kuppeveld, professor virology, University of Utrecht). A temperature of 19°C  to 24°C (66°F to 75°F) helps you to prevent the drying of your nasal passage. So that you are less susceptible to viruses.

FIG. 1. Survival of TGEV and MHV at 4°C and (a) 20% RH, (b) 50% RH, and (c) 80% RH. Squares, TGEV; circles, MHV. The error bars indicate 95% confidence intervals. How temperature and humidity have effect on survival of virus

Research by Lisa M. Casanova et al shows that the infection rate of viruses is significantly reduced when the temperature indoors at room temperature (20°C or 68°F) compared to colder temperatures (4°C or 39°F). However, when the temperature is warmer (30°C or 86°F), the transmission of influenza viruses is blocked or becomes very inefficient (Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces, Lisa M. Casanova et al, Applied and Environmental Microbiology, May 2010)

But of course, many people don’t find an indoors temperature of 30°C comfortable. To maintain your indoor temperature at room temperature makes you feel comfortable. It also lessens the risk of virus transmission.

Temperature, Humidity and Covid-19

Temperature and humidity go hand-in-hand. Research shows, that the Covid-19 virus can survive several hours and even several days on surfaces.

Of course, the greatest spread of the virus is via ‘direct’ contact: not keeping the physical distance, so that the virus is transmitted via the large droplets via talking, coughing or sneezing.

The WHO mentions that people can be infected with Covid-19 by touching their faces after they have touched contaminated objects and surfaces (WHOS’s Guide for Worker Safety, March 2020).  

In general, infections via surfaces and then touching your face appear to be the least of threats to spread Covid-19. It is uncertain how much people get infected by Covid-19 via air: do the so-called ‘aerosols’ contain enough virus to get someone ill? Poor conditions of ventilation may play a part. Of course, there are already some new variants of the virus, such as the British variant, which have more virus material in the droplets.


The ‘Alara’ principle is a sound mechanism. This means: the As Low As Reasonably Achievable principle.  It is always good to lessen risks.  Spread of the Covid-19 virus via contaminated surfaces or air may not (or may) the most principal risk… but it means there is still risk. Besides, an optimal environment helps to lessen the spread of other viruses and is good practice of hygiene.

Solutions like the Covid Airmex can help you to monitor your temperature, humidity, tvoc and co2, for a safe and healthy working environment

For feeling comfortable indoor, humidity is one of the most important factors, both physical and mentally. Where temperature is immediately perceived (‘cold in here’), humidity is also one of the most important factors for feeling comfortable indoors. Besides, temperature and humidity go hand-in-hand. Besides, humidity plays a factor in the growth of molds and other allergens.

Indoor air humidity

Humidity is the concentration of water vapor present in the air. Humidity depends on the temperature and pressure. Warm air is able to bind more water than cold. The same amount of water vapor results in higher humidity in cool air than warm air. So, humidity is also important how we experience the temperature. Many measurements of humidity consist of relative humidity: how much water there is in the air relative to the maximum of water it can contain given the same temperature. Regulation the indoor humidity and temperature go together.

Effect of humidity on well-being and health

Humans are more sensitive to changes in temperature than in relative humidity. However, humidity is an important factor in thermal comfort: the condition of mind that expresses satisfaction with the thermal environment. Outdoor, humidity has a much stronger influence at higher than at low temperatures.

Human bodies use evaporative cooling to regulate temperate as primary mechanism. The rate of which perspiration evaporates on the skin is under humid conditions lower than in arid ones. Humans feel warmer at a relative high humidity, because humans perceive the rate of heat transfer from the body rather than the temperature itself.

High humidity (‘humid air’) or low humidity (‘dry air’) can have negative effects on well-being and health. You can feel some effects immediately and they disappear when the humidity is adjusted (or when you leave the room), some effects may rise years later.

Effects of dry air

Dry air may cause:

  • Dry eyes
  • Chapped lips
  • Bloody nose
  • Itching of the nose
  • Irritation of the skin
  • Allergy problems and asthma

Tissue lining of the nasal passages may dry and crack due to low humidity. Besides, it may become more susceptible to penetration of the rhinovirus cold viruses. Very low humidity not only may create discomfort, but respiratory problems and aggravate allergies.

When humidity drops below 20%, it may cause eye irritation.

Dry air during winter

You have probably experienced yourself: at winter, indoor air quality is often rather dry. When temperature decreases under 0°C, relative humidity can drop to 20%. However, ‘good’ indoor humidity should be between 20 and 40%. Especially in winter, a humidity above 30% is preferred to reduce the change that the nasal passages dry out.

The cause of dry air is often the room temperature. That’s why room temperature should be kept under 22°C (72°F).

Humid air

Some effects of humid air indoor:

  • Fatigue
  • Frizzy hair
  • Feeling hot or sweaty
  • Sleep interruptions
  • Respiratory problems
  • Allergy problems and asthma

As said above, some people may suffer respiratory problems. Some of these problems may be related to conditions as asthma or may be caused due to anxiety. Many people hyperventilate as response. This causes feelings such as loss of concentration, numbness or faintness.

Humid air during summer

During summer, the ideal indoor humidity is between 30% to 50%, following the high humidity outside. In any case, constant humidity must be kept under 60%, to prevent the growth of microbes.

Humid air during winter

In some cases, the indoor humidity may rise above 45% during winter. Mostly this is caused by human activity with poor ventilation. The most immediate visible effect is condensing on cold surfaces as windows. When there is often the case of humid air, condense may affect the structure of the building and can cause health problems.

Solutions like Airmex can help you to monitor your humidity, for a comfortable, safe and healthy working environment.

Did you ever wonder where you are most exposed to air pollution? Somewhere outside, you say? Wrong, you breath the most polluted air… indoors! Research shows, that people spend 90% of their time indoors. Isolation and modern heating have brought us comfy, warm indoor environments: home, work, recreation, etc., with no cold air coming from under the doors. However, in many buildings there is a downside. With the tightly enclosed indoor environments, pollution caused indoors or coming from outside has no opportunity to mingle with fresh air. For viruses, heat and certain levels of immunity are perfect environments to stay active. Besides, the Covid-19 virus is spreading.

Indoor concentration of pollution often 2 to 5 times higher than outdoor

Research on the United States Environmental Protection Agency (EPA) site shows:

  • “Americans, on average, spend approximately 90 percent of their time indoors,1 where the concentrations of some pollutants are often 2 to 5 times higher than typical outdoor concentrations.2
  • People who are often most susceptible to the adverse effects of pollution (e.g., the very young, older adults, people with cardiovascular or respiratory disease) tend to spend even more time indoors.3
  • Indoor concentrations of some pollutants have increased in recent decades due to such factors as energy-efficient building construction (when it lacks sufficient mechanical ventilation to ensure adequate air exchange) and increased use of synthetic building materials, furnishings, personal care products, pesticides, and household cleaners.”

Why is air quality important?

You probably know the irritation of eyes or a dry troath yourself. Indoor air pollution can have serious health effects, ranging from irritation of your eyes to respiratory diseases:

  • Irritation of the throat, nose and eyes, such as a dry throat
  • Headaches, dizziness, and fatigue
  • Respiratory diseases, heart disease, and cancer

Indoor concentration of pollution often 2 to 5 times higher than outdoor

“The link between some common indoor air pollutants (e.g., radon, particle pollution, carbon monoxide, Legionella bacterium) and health effects is very well established.

  • Radon is a known human carcinogen and is the second leading cause of lung cancer.4, 5
  • Carbon monoxide is toxic, and short-term exposure to elevated carbon monoxide levels in indoor settings can be lethal.6
  • Episodes of Legionnaires’ disease, a form of pneumonia caused by exposure to the Legionella bacterium, have been associated with buildings with poorly maintained air conditioning or heating systems.7, 8
  • Numerous indoor air pollutants—dust mites, mold, pet dander, environmental tobacco smoke, cockroach allergens, particulate matter, and others—are “asthma triggers,” meaning that some asthmatics might experience asthma attacks following exposure.9

While adverse health effects have been attributed to some specific pollutants, the scientific understanding of some indoor air quality issues continues to evolve. …

One example is “sick building syndrome,” which occurs when building occupants experience similar symptoms after entering a particular building, with symptoms diminishing or disappearing after they leave the building. These symptoms are increasingly being attributed to a variety of building indoor air attributes.

Researchers also have been investigating the relationship between indoor air quality and important issues not traditionally thought of as related to health, such as student performance in the classroom and productivity in occupational settings.10

Solutions like the Covid Airmex can help you to monitor your temperature, humidity, tvoc and co2, for a safe and healthy working environment