Weather is not a constant feature. One day it’s raining and the wind is blowing, the next day the sky is blue and the sun is shining. This causes the temperatures unpredictably to go up and down, also inside a building. A good ventilation system ensures that the temperature of fresh air brought in from outside is matched to the temperature of the indoor air present. Whether you’re working in the office, sitting and reading a book at home or attending courses at school, the environment you are in determines the effect that different temperatures can have on your overall mental and physical wellbeing. Temperature defines how hot or cold something is and can be measured in degrees Fahrenheit (°F) or Celsius (°C). Air temperature is the temperature of the air excluding wind chill or humidity, as these can make a temperature feel colder or warmer.

What is more important for our feeling of comfort inside is the surrounding or (ambient) room temperature, meaning the average temperature within a room. It is often referred to as the temperature in which most people feel comfortable inside, not too hot nor too cold. This temperature can vary from person to person, but typically lies in the range of 21°C – 25°C. This range is generally referred to as the thermal comfort zone.

When the surrounding temperature levels are too high, we immediately feel the impact this has on our bodies. We feel clammy and become tired. Lowering the temperature too much however, can also have an adverse effect on our mind and body. Our concentration level decreases and the only thing we want is getting warm. With temperatures between 18°C-20°C it already feels a bit cooler. This is called the tilting zone. It can feel unpleasant but is not unhealthy. Most people can adapt well to this temperature. The cold creates a slight stress stimulus. That makes you a little more alert, allowing you to work more concentrated. Still, it’s a matter of dosing. The effect of a sharpened focus will disappear if you’re in the cold for too long. Then the discomfort takes over and it will be harder to concentrate. It is also important to watch out for people with cardiovascular disease and for the elderly. The cold increases blood pressure and pressure on the heart, which can be dangerous. Temperatures between 15°C-17°C are acceptable for a short period only or when performing a heavy task but not when you’re sitting still. Long-term exposure to inside temperatures below 15°C has negative effects on our health.

It is safe to conclude that, since the perception of temperature differs from person to person, it is important to pay attention to this when ventilating a space. A general feeling of wellbeing for everyone should be created.

In order to fully understand this term, let us start with explaining the difference between absolute and relative humidity. Water can exist as a liquid, solid (ice) or gas (water vapour). Water vapour increases primarily in the atmosphere through evaporation. Liquid water evaporates from oceans, lakes, rivers, plants, the ground, and fallen rain. Water vapour or moisture can be present in the air. Winds in the atmosphere then transport the water vapour from one place to another.

Absolute humidity (expressed as grams of moisture per cubic meter of air) is a measure of the actual amount of water vapour in the air, regardless of the air's temperature. The higher the amount of water vapour, the higher the absolute humidity. Specific humidity refers to the weight of water vapour contained in a unit weight of air (expressed as grams of water vapour per kilogram of air). Absolute and specific humidity are quite similar in concept.

Relative humidity (RH) (expressed as a percent) also measures water vapour, but relative to the temperature of the air. To put it simply, relative humidity indicates the actual water content of air as a percentage of the maximum amount it could possibly hold at its current temperature. Warm air can possess more water moisture than cold air, so with the same amount of absolute/specific humidity, the relative humidity of cold air would be far higher than of warm air.

Within the context of workplace health and safety, maintaining suitable temperature and relative humidity levels is necessary in order to sustain employee health, comfort, and productivity. A poor relative humidity level, resulting in dry air, leads to dry skin, itchy eyes, and irritated nasal passages. It can cause a bloody nose or an itchy throat and can aggravate symptoms of the common cold and some respiratory ailments. It also increases static electricity, which you feel in your clothes and hair and on furniture and carpeting. Too high relative humidity degrees will result in condensation forming on windows, walls and ceilings that are colder than the air temperature and potentially damaging building materials and causing odours in poorly ventilated spaces. In order to prevent possible mould growth and/or foul odours, it is also important to know the indoor dew point of a facility.

When we are talking about indoor dew point, we are talking about temperature. More precisely, the temperature that tells us when condensation in a building is likely to happen. In other words, the temperature to which air must be cooled in order to reach saturation. The higher the dew point, the more moisture in the air. The dew point can be calculated based on the air temperature and relative humidity level.

It is safe to say that, by being able to monitor the temperature and humidity levels in our home or offices, we are able to better understand and better yet, to control this rise and fall in comfort and sense of wellbeing. Bearing this in mind, Sentera developed a wide range of temperature and humidity sensors. Typical applications are humid spaces like bathrooms and wine cellars but also kitchens, changing rooms, swimming pools etc. Since both temperature and humidity are such determinant factors for our wellbeing, also our CO₂, VOC and CO/NO₂ sensors measure these values.