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Indoor Climate: How to Protect Yourself from Viruses in Winter

2.12.2021
  1. The ideal indoor climate in winter
  2. The indoor climate and your health
  3. Why is 40 to 60 % humidity healthier?
  4. The indoor climate and your well-being
  5. The indoor climate and your sleep
  6. The indoor climate and your performance
  7. How to measure air quality
  8. How to effectively reduce the aerosol concentration
  9. The 5 biggest advantages of humidification systems



Do you often have a cold in winter? Are your eyes regularly red? Does your skin dry out and crack? Does your nose bleed regularly? Do you sleep restlessly? Do you have trouble concentrating? If at least one of these points applies to you - or someone in your household - you should think about the indoor climate. With an air humidification system, you will improve the air quality sustainably and protect yourself effectively against viruses.

The ideal indoor climate in winter

In the winter half-year, we spend almost the entire day indoors. Experts recommend a relative humidity of 40 to 60 % and a room temperature of 20 to 22 degrees in living rooms. During the heating season, however, the air indoors is often much drier. This is detrimental to our well-being and, above all, our health.

The indoor climate and your health

Bacteria, germs and viruses feel at home in dry air and multiply faster and more strongly. That is why we suffer more often from bronchitis, flu, coughs, sinusitis or colds in rooms with too little humidity. In addition, viruses, germs or bacteria survive longer in dry air and aerosols spread more easily. Every time we breathe or talk, but also when we laugh, shout or sing, aerosols become airborne and can spread flu viruses or Sars-Cov-2 viruses. Aerosols spread particularly well in poorly ventilated rooms and excessively dry air.

Why is 40 to 60 % humidity healthier?

At a relative humidity below 40 %, water evaporates more quickly and the aerosols crystallise. This process preserves the viruses in the aerosols, which thus remain suspended for longer and spread much more strongly indoors. This increases the potential for infection. In winter, the humidity in heated rooms drops to 20 % or lower. 40 to 60 % humidity is ideal because ...

  • ... aerosols bind the moisture in the air, become heavier and sink to the ground.
  • ... aerosols have an ideal salt solution that deactivates viruses.
  • ... our immune system works particularly effectively and repels, fights and removes germs.

Houzy Advice

Good to know

Relative humidity between 40 and 60 % strengthens our immune system and prevents our mucous membranes from drying out. That is why we suffer less often from flu, respiratory diseases or allergies.

Monitor the humidity and room temperature with a hygro / thermometer. Simple devices are available in specialist shops from 20 francs.


Interior climate: Hygro- / Thermometer
With a hygro / thermometer you monitor the humidity and room temperature.

The indoor climate and your well-being

  • In the heating season, the air is drier and draws more moisture from our skin. The lips become chapped, the skin dries out and becomes chapped, the hands become rougher, in the worst case the skin cracks or becomes inflamed.
  • The eyes are particularly sensitive, which is why they react very sensitively to too little humidity. For example, with reddened eyes, swollen eyelids, eye fatigue, high sensitivity to light and headaches or irritations and inflammations when the tear film is too thin to protect the eyes from environmental influences such as dry air.
  • When the indoor climate dries out the mucous membranes, we have to cough or become hoarse. A few percent more humidity could prevent this and have a lasting positive influence on our health and well-being.

Houzy Advice

Good to know

The indoor climate is not only important for your well-being. Your pets also feel more comfortable. And your wooden furniture or parquet floors last longer if the humidity is right.

Condair Cube

Small and precise: the Condair Cube

Don't give viruses and bacteria a chance! The mobile and compact Condair Cube measures air quality quickly and precisely.
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The indoor climate and your sleep

On average, people spend a third of their lives asleep. That is why the indoor climate in the bedroom is even more important than in any other room. If you regularly wake up at night because you have to cough or sneeze or your partner snores loudly, you will wake up the next morning overtired. The right humidity (up to 50 %) and room temperature (18 to 20 degrees) avoid coughing, hoarseness or excessive snoring and ensure a deep, healthy and above all restful sleep.

Houzy Advice

Good to know

Children react more sensitively to environmental influences than parents. That is why you should pay attention to a healthy room climate in the children's room. After all, your children spend a large part of the day there when they play, sleep, listen to music, read or do homework.

The indoor climate and your performance

CO2 is an indicator of air quality. The higher the CO2 content, the worse the indoor air - and the more likely aerosols also transmit flu viruses or Sars-Cov-2. The concentration is measured in parts per million (ppm). Outside, the air normally has a CO2 concentration of about 400 ppm. Values below 1200 ppm are considered safe, but above 800 ppm of carbon dioxide in the air our ability to concentrate decreases. That is why a good indoor climate is especially important in rooms where concentrated learning or work takes place, for example in a child's room or home office.

How to measure air quality

From 1200 ppm you should be concerned about the indoor climate, from 2000 ppm you must act urgently and improve the fresh air exchange. You can monitor the indoor climate with an air quality monitor. Since the outbreak of the Corona pandemic, several new devices have come onto the market. They measure carbon dioxide concentration, humidity and temperature and warn according to the traffic light system:

  • Green: Optimal, you do not need to do anything.
  • Yellow: Caution, you should ventilate, for example, so that the CO2 and aerosol concentrations in the room decrease.
  • Red: Caution, the CO2 concentration is too high, you must act quickly.

When the traffic light is on yellow, it is usually sufficient to ventilate and humidify the air, for example with a mobile humidifier. As soon as the traffic light is on red, this is no longer enough to protect you and your family from viruses, which spread strongly in the high aerosol concentration. In addition, you must regularly fill mobile humidifiers with water and clean them.

How to effectively reduce the aerosol concentration

With a ventilation system with integrated humidification, you play it safe. Innovative solutions such as the Condair HumiLife diffusion humidification control the air humidity with sensors, regulate it automatically and keep it constantly at the desired value between 40 and 60 %. Such professional humidification solutions can be installed inconspicuously in any house or apartement and are connected directly to the water circuit. They operate energy-efficiently and silently, are hygienic, require hardly any maintenance and also meet standards such as Minergie-A, Minergie-P or SNBS Hochbau (Standard for Sustainable Building in Switzerland).


The 5 biggest advantages of humidification systems

  1. You only need one system for your home instead of a mobile humidifier in every single room.
  2. You can adjust the humidity in every room and keep it in the healthy comfort range.
  3. You can constantly monitor the air quality and control the system with the smartphone app.
  4. You never have to refill water or clean the humidifiers again.You can also install a system like Condair HumiLife in a Minergie or passive house.

Prevention is better than cure: With a modern ventilation system with integrated air humidification solution, you effectively protect yourself from viruses such as flu viruses or Sars-Cov-2. Especially in the winter half-year, when the humidity in heated rooms often falls below the recommended 40 %.

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