Brief history of ventilation systems

Ventilation systems throughout history

The concern for achieving clean air inside buildings has accompanied man throughout his history. Already in ancient Rome, the Greek physician Galeno (129 A.D. /216 A.D), presented his knowledge on this subject in a medical synthesis known as Galenism. In it he establishes among other principles that it is essential to maintain or seek the purity of air (the "good air"), proposing if necessary the use of perfumes, fumigations, etc. Impure or corrupt air (the "bad air") was considered by Galeno to be the sure cause of epidemics or infectious pathologies.

The relationship between one aspect and another was also presented by Florence Nightingale (1820-1910), considered the mother of modern nursing, who described the importance of ventilation in her "Notes on Nursing". Together with temperature, lighting, diet, hygiene, and noise, ventilation was the basis for achieving a healthy environment. Florence Nightingale instructed her nurses to ensure that the air was suitable and periodically renewed, considering it vital for the recovery of patients. These hygienist approaches conditioned the architectural design of buildings in the 20th century, when constructive typologies that included interior patios began to be used, facilitating openings in the facades to create a cross ventilation inside the rooms. Shafts and ducts were also incorporated to ventilate bathrooms. The appearance of reinforced concrete and the possibility of constructing lightweight enclosures allowed for the opening of large openings in the facades that significantly improved the lighting and ventilation of the interiors of homes, and with it their health conditions.

Current trends

Currently, it is again confirmed that indoor air contamination in buildings is the cause of multiple health problems that can range from simple fatigue to symptoms compatible with allergies, infections, etc. In some cases, serious diseases such as cancer can be triggered if asbestos particles are inhaled or if there is contact with radon gas. The construction of increasingly airtight buildings was promoted starting in the 1970s as a response to the excess energy consumption that conditioning all interior spaces entailed. This forced buildings to be equipped with mechanical ventilation systems that regularly renewed the air indoors.

Current ventilation systems such as double flow mechanical ventilation, promote the renewal of contaminated air with energy efficiency criteria. In this type of ventilation, a notable energy saving is achieved by using a heat exchanger, capable of capturing the heat from the contaminated air extracted from the home and transferring it to the clean air coming from outside, so that ventilation does not produce a cooling of the interior rooms with the consequent increase in heating consumption. This objective is also achieved through sensors that activate the ventilation system to introduce exactly the necessary air flow at each moment. These sensors can measure the degree of humidity as happens in hygrosensitive systems, or also the level of CO2.