Ventilation in elevator shafts and the regulations to follow

Fewer and fewer people are afraid of elevators. And it’s normal, because there are also taller towers where it is practically mandatory to use them, and they have become commonplace. Furthermore, nowadays, they no longer make strange noises or are uncomfortable. However, one of the fears that has always existed with elevators is the fear of getting stuck and running out of air. What truth is there to this? We can see it in the regulations on air renewal and ventilation in elevator shafts. Its function is to avoid regrettable risk situations.

In reality, elevators today are safe so that, in the event of a prolonged blackout or being trapped in the cabin, the people inside do not have to worry about their breathing. On one hand, alarm systems alert early of problems in an elevator. But, above all, it is ensured that ventilation in the elevator is guaranteed, and as far as possible, temperature control is also taken into account to prevent a sudden rise in heat or cold.

Moreover, it is common to find systems that even in operational moments provide good climate control, especially in outdoor elevators, which are very sensitive to the outside climate. But ultimately, to ensure air quality in elevators, the most important thing is to control the elevator shaft.

What is the elevator shaft? We can define it as the interior space where the cabin is placed, which includes the motor, pulleys, and all the machinery. When we refer to this space, we mean the interior that runs the entire path that the cabin will take. And when we talk about ventilation in elevators, we must ensure that the passage and circulation of air is correct in this space.

More than anything, because elevators have grilles and even fans for intake and exhaust within the cabins. But this air will be directly affected by the ventilation in the elevator shaft. For this, we must see what the regulations say.

According to regulations EN 81-20 and EN 81-50, the most recent for elevators, it specifies regarding ventilation in the elevator shaft that:

• The shaft must be properly ventilated and must not be used for the ventilation of spaces unrelated to elevator service.
• Ventilation openings must be provided, located at the top of the shaft, with a minimum total surface area of 2.5% of the cross-sectional area of the shaft. This ventilation can be achieved through the machine room or pulleys or directly to the outside.

Nevertheless, the necessary temperature within the room where the machines are located must also be taken into account. In this case, the ventilation of the elevator shaft must ensure that there is a temperature between 5°C and 40°C.

In any case, what is important is to guarantee ventilation in elevator shafts, so that we can have air circulation in the cabin at all times, especially in the event of a technical problem or a supply failure.

The most common system has always been to connect the elevator shaft to the outside, in order to renew air naturally. However, nowadays, it requires in many cases the existence of mechanical ventilation systems. The airflow in the cabin is achieved, as we have discussed, by means of fans and intake grilles.

Ventilation in outdoor elevator shafts

Elevators that are located outdoors pose an added problem, especially in locations exposed to cold in winter but above all during summer in hot climates. In the first case, if the outdoor elevator suffers from extreme cold, it can hinder mechanical function, but people will not feel any colder than outdoors.

The problem is greater in summer and in very warm locations. It is worth noting that outdoor elevators are those found on avenues and streets, usually to access elevated locations. Although they can also belong to private initiatives.

In many outdoor elevators, it was found that in summer the ventilation was insufficient. For example, the Cádiz City Council had to install a better ventilation system in elevator shafts for some of the outdoor elevators it had in the locality. In both cases, it was necessary to achieve better air renewal when high temperatures were reached, as without it the cabin could reach 40°C, which was initially uncomfortable for users, but very dangerous in the event of a technical failure. It should be taken into account that outdoor elevators have greater complications, as the shaft is in direct contact with the outside climate.