Measure humidity – What you need to know
The easiest and most effective way to measure humidity is with a hygrometer. The device continuously monitors the indoor climate so that you can react early if the room humidity is too high or too low over a longer period of time. Measuring humidity is important for achieving and maintaining an optimal and healthy indoor climate with a relative humidity of 40 to 60 percent.
What exactly is humidity? 🧐
Put simply, humidity is the amount of water vapour in the air. A distinction is made between absolute and relative humidity. You can find a detailed explanation of this in our blog post "Absolute and relative humidity". For more information on the topic of optimal humidity, click here.
How to measure humidity correctly 💁🏻♀️
You can easily measure the humidity in a room with a hygrometer. There are also other methods, which we will show you in the next section. Regardless of whether you measure with a hygrometer or an alternative method, there are a few points to consider.
The temperature in the room determines how much water vapour the air can hold. Accordingly, the relative humidity rises or falls when the room temperature changes. You can find detailed explanations of optimal humidity here:
As the temperature varies from room to room, the humidity should be measured separately in each room.
It is equally important to measure room humidity throughout the year. This is the only way to detect changes and, if necessary, take measures to maintain an optimal indoor climate.
The location where the measurement is taken is also crucial. If the room humidity is measured near a heat source, at a window or in a draught, this can lead to a false result.
How to measure humidity correctly
- Set up a hygrometer in each room or attach one to the wall.
- Always measure in the same place.
- Measure as centrally as possible in the room.
- Do not measure near a door.
- Do not measure next to a window or on a window sill.
- Do not measure around a radiator or an air outlet.
- Monitor each room separately.
- Measure and monitor room humidity over the long term.
- When mounting on a wall, do not attach to a cool exterior wall.
Why is it important to measure humidity? ☝️
Humidity has a significant impact on our health and well-being. Excessive indoor humidity can promote mould growth and allergic reactions, while low humidity can lead to dry mucous membranes and irritated eyes, among other things. Humidity also affects the durability of materials in buildings and can impair the efficiency of heating and cooling systems. At home, in public buildings or in industry, the right humidity plays a decisive role in comfort and functionality – so you should measure the humidity on an ongoing basis.
Depending on whether the air is too dry or too humid, different measures are required. Prevent mould and other effects by measuring the humidity.
- Important information about excessively dry air
- Find out more about what you can do about excessively humid air
What devices and methods are available for measuring humidity?
Hygrometers
Hygrometers are generally considered the simplest way to measure humidity. These humidity measuring devices are available in analogue and digital form.
Digital hygrometers use electronic sensors to measure humidity and temperature. Once correctly positioned in the centre of the room and after a short period of adjustment, the humidity and temperature can be read on a digital display.
Mechanical (analogue) hygrometers work without electricity and use certain materials with hygroscopic properties that react to moisture. The best known are the hair hygrometer and the spiral hygrometer.
Other types include absorption hygrometers, aspiration hygrometers, chemical hygrometers, coulometric hygrometers, optical hygrometers and dew point mirror hygrometers.
Alternative methods for measuring humidity
🌡️🌡️ Psychrometer
Two thermometers are placed next to each other. One of them is moistened during the measurement, the other is not. The greater the temperature difference, the drier the air.
🧊 Ice cube test
A glass filled with ice cubes is placed in the middle of the room. If the outside of the glass forms a lot of condensation after a few minutes, the humidity is too high. If the glass remains dry, the room humidity is also rather dry.
🌲 Pine cone method
For this, you need a dry pine cone. Place it upright in the centre of the room. Stick a toothpick to one of its scales. If the cone becomes damp, it will shrink and the toothpick will move upwards. This is an indication that the room is very humid.
📞 Smartphone apps
There are also apps that claim to measure humidity. However, very few mobile phones have a built-in sensor that is necessary for accurate measurement. Therefore, most apps rely on weather data, which is not the same as measuring room humidity.
How do room usage and season affect the measurement? ☀️❄️
As described at the beginning, temperature has a decisive influence on relative humidity. Temperature fluctuations are caused by outdoor weather conditions. In winter, the air entering the room from outside is colder and drier than the air in summer, which is often warm and humid. Depending on the season, a room may be too dry or too humid. This is because warm air can absorb and store more moisture than cold air.
On the other hand, the use of the room can also influence the humidity. For example, the humidity in a kitchen is higher than in a living room due to the steam and heat from the oven and stove.
There are different recommendations for the optimal humidity and temperature for different rooms. We have compiled a table for you here.
Measuring humidity is worthwhile for everyone
It is worth measuring the humidity regularly. With a hygrometer placed in the optimal location in the room – i.e. away from windows, doors and radiators – you can detect changes at an early stage. This gives you the opportunity to take the appropriate measures, seek professional advice * or upgrade your technical equipment. Regular monitoring and early intervention can protect you and your loved ones, as well as your furnishings, textiles and building materials.
FAQs on measuring humidity 💡
There are various methods. The simplest is to use a hygrometer.
With a hygrometer placed centrally in the room. It should not be placed near a window, door or radiator, nor should it be attached to an exterior wall.
We have compiled a table with the recommended values for each room. You can find it here.
You can find interesting facts about indoor air quality in our blog.
Tips for storing food correctly
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Storing herbs and spices – the right indoor climate
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How economical heating can lead to the formation of mould
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What does a hygrostat do and when is one useful?
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Humidity and health: creating the right balance with the right indoor climate
Read moreSuitable products for measuring humidity
