Control the humidity level with mechanical ventilation

Condensation humidity from water vapor is one of the worst problems -and also one of the most common- that buildings suffer from, especially older ones. In modern construction, if the criteria of the Technical Building Code are followed, it is possible to control the humidity level without problems, as the construction methods described in the text ensure that vapor condensation does not occur in the air. What method is best to combat humidity in older homes?

The solutions against humidity in homes are varied. And almost all are based on the same principle: ventilating the affected area so that the air stops having an excess of vapor. Painting the walls and other supposed solutions, for example, are a mistake and do not work. Everything boils down to better ventilation, either naturally or by installing professional solutions.

Of course, if the humidity problem persists, the best solution will always be to opt for a mechanical ventilation system. At the very least, an extraction solution in areas where vapor condensation occurs is the perfect way to renew the air. Especially in areas like kitchens or bathrooms, which are the most affected and where it is most difficult to control the humidity level.

It may seem that the most natural solution to a problem like humidity is to let the outside air in, but in reality it is mechanical ventilation and especially dual-flow systems that will best act against humidity. And also in the most natural way, as it will not only guarantee air renewal, but it will also do so in the right measure. Thanks to mechanical systems, the entire room receives fresh air and there are no leakage areas, unlike what can happen when simply ventilating the room.

The Technical Building Code itself specifies this in its Basic Document of Health and Indoor Air Quality. It is clearly stated that the minimum conditions that a home needs to have the necessary health values require an appropriate ventilation system for the building. And to control the humidity level, this installation must meet the minimum air renewal requirements mentioned in the text.

Those values that the ventilation system must adapt to are not always the same. The same document in the CTE clarifies what flows are necessary for each specific situation. The necessary calculations must be made for each case and ensure adequate ventilation flows.

Systems to control the humidity level

There are many false solutions against humidity, and in the end, the only infallible method is mechanical ventilation itself. Whether single flow with ventilation grilles or double flow. The latter is always the best option, as it can control the extraction and introduction of air, in addition to having an energy recovery unit.

Mechanical ventilation systems can also include detectors to control the humidity level. In this way, they can activate the system and adapt its use to the exact conditions required at any given moment. Also depending on temperature and the number of people present in the room.

Before installing a ventilation system, there are other options to consider:

• Be especially careful with kitchens and bathrooms. Use extractors when cooking and ventilate the sinks when they are being used. Sometimes, what happens is simply a lack of renewed air in those rooms.
• Humidity leaves stains on walls and odors when levels have already exceeded acceptable limits by a lot. A stain on a wall, for example, does not mean that the humidity originates there, so just painting over it does not solve anything. On the contrary, it merely hides a problem that will eventually resurface.
• Dehumidifiers can be used if we want to control the humidity level in the air. They are usually efficient depending on the situation.