Achieve a relative humidity at home

When we refer to achieving comfort at home thanks to good ventilation, we often focus on ventilation systems and achieving good energy efficiency. We want costs to be minimal and to take advantage of technology to ventilate better. However, to really find ourselves in good comfortable conditions, we must also concern ourselves with the healthiness of the home. And for that, we cannot overlook the levels of relative humidity, which if high can lead to problems.

The humidity in the home is not simply an indicator of the volume of water in the air. It is also responsible for temperature changes, deterioration in the building, and, worse yet, possible health problems in people.

And we must keep in mind that relative humidity has a direct impact on us and also on our environment. The differences with absolute humidity are technical: relative humidity is the “mass of water vapor in the air per volume divided by the mass of water vapor per volume at the saturation point at the same temperature,” while absolute is simply the weight of water vapor contained per unit of volume of air, generally measured in Kg/m3.

However, absolute humidity is of little use to measure the healthiness of a space, while relative is extremely important because it tells us the total humidity with respect to the saturation point, one hundred percent.

If the saturation point is reaching the total, that 100%, relative humidity can tell us key aspects in a building. If, for example, we want to dry the clothes and the humidity is at 70%, it will be much harder than if it were only at 30%.

It is very important to control relative humidity indoors. Being below levels can cause dryness, but above can be a dangerous agent that puts the healthiness of the home at risk. In addition, it can lead to the following negative consequences:

• It influences the thermal sensation of the rooms, making the effects of cold and heat more noticeable. With humidity, winters feel colder and summers feel hotter.
• It creates the ideal environment for the appearance of mold. Mold can appear, but also mites and other harmful agents that cause allergic ailments, as well as causing bad smells.
• It increases the emission of chemical products (formaldehyde, among others) from the materials we have in the home.

What to do to decrease relative humidity?

Being able to control relative humidity levels in our homes is essential. Especially in old buildings and in buildings that may be affected by excess water vapor.

The first thing is to consider the ambient humidity in the building, a parameter that will tell us about air quality indoors. This means that we must consider the dry temperature of the air, air speed, and even the clothing of those occupying the building, along with relative humidity. Those values also matter.

This is because the optimal relative humidity conditions vary from winter to summer. According to what is estimated by the Thermal Installations Regulations in Buildings (RITE), in winter the relative humidity should be between 40% and 50%, with a temperature around 22°C. In summer, on the other hand, with a temperature around 24°C, it is estimated that the relative humidity should be between 45% and 60%.

That humidity of 60% is the maximum we should not reach if we do not want mold to appear and health problems to begin to arise. The same RITE explains how to improve air quality to solve this problem.

To measure air temperature, we can use a hygrometer. Quite affordable, the most modern ones measure temperature along with relative humidity, as well as being able to monitor a specific space for a certain period of time.

Of course, the best way to combat humidity is through air renewal. A mechanical ventilation system can carry out this task and extract stale air from the interior to replace it with fresh air from the exterior. There are different ventilation solutions that can help us reduce relative humidity levels in our homes.

It is also important to remember that very low water vapor levels in the environment are not positive either. However, it can easily be solved with vaporizers that release particles into the air. Although the biggest problem with relative humidity is that it can affect those who inhabit a place.