History of good air!
The history of indoor air is largely the history of the triumphs of mechanical ventilation. At the same time, modern ecological building has brought about a renaissance for the technology of natural ventilation. That the British Houses of Parliament were at the forefront of technical development in a country that was the birthplace of industrialism is only logical. But even though the technology had been refined 150 years later, British architect Norman Foster chose a solution based on natural ventilation for the new German parliament in Berlin. From a user perspective, well-functioning natural ventilation is unsurpassed. No noise from fans, and stable systems that are always in operation. In Germany, offices are more often ventilated by opening windows than by mechanical ventilation systems. This is probably energy-efficient in a country with a relatively mild climate. If energy use is to be reduced in cold countries, there is no alternative to extracting heat from vitiated air leaving the building in order to heat the inflowing air. Today, when buildings are equipped with advanced fan systems, it is more for the sake of humanity than for human wellbeing.
Energy-efficient, complicated and quality ventilation!
In a long-term perspective, our way of creating indoor climate seems hopelessly primitive. Energy-efficient, complicated and with dubious quality. In addition, we are not accustomed to buildings in which the temperature is essentially constant year-round and at all hours of the day and night. Furthermore, we are not accustomed to building them. In times past, ventilation focused almost exclusively on getting rid of indoor air vitiated by human activity. But air quality can also be compromised by materials or by ventilation itself. The fatal components are often very marginal compared to the total volume. Glue, paint, plaster and plastic can give great cause for discomfort, even in there original state; but unlike wood, stone and metal, there is no telling what can happen when they are exposed to heat and moisture. Good indoor air often begins with sound building technology.
Expectations with respect to a completely stable indoor climate are still characterized by novelty. Not long ago, this was a luxury enjoyed by few. In addition, an indoor climate offers sensual qualities that can be allowed to vary: to be able to sleep in a cool room, or to be able to feel the warmth of a fire. Actually, only long-term sitting requires an even temperature and airflow. There is good reason to believe that technological development can open the way for variations in indoor climate over time and space. This would be both energy-efficient and sensual.
Saving energy often means accepting nature. Scandinavians live in a part of the planet that is favourable in many ways. It is seldom necessary to cool the air. The student union building at Chalmers University is one of the buildings that Wingårdhs has designed in which mechanical ventilation and natural airflow work hand-in-hand. If one can accept that it will be a little warmer in the building during the few days of the year when the temperature in Gothenburg exceeds 23 degrees Celsius, then the savings, in terms of both building and usage, are considerable.
Ventilation solutions that take advantage of architecture are most easily realized in structures in which the high, public spaces can draw the air out of low ceilinged rooms. This is how both Ale and Chalmers work, as do Universeum and the tall new office building at Astra Zeneca in Mölndal. The air moves diagonally through the smaller rooms and out into the atriums where it naturally finds its way towards the roof and out into the open. The large room is not merely an architectural expression; it contributes to good air quality and silent spaces at low cost.
Air should always be light!
The history of air has largely concerned the solution of problems caused by the buildings themselves. Even though the choice of natural or mechanical ventilation influences the architecture, technology is still expected to fulfil the task, unnoticed, of supplying rooms with reasonably good air. We know that this in not always the case, but what is more – the air can be transformed into a real, sensual quality – part of what we call atmosphere. Just as the air by the seaside, in pine forests or in high mountain areas has its own particular qualities, there is indoor air that can be inhaled with pleasure. Greenhouses, cool stone churches and log houses have an atmosphere that is directly related to our experience of air. Scent is significant. Coffee roasteries, spice warehouses and root cellars can make nostrils flare inquisitively or noses turn up in repulsion. But even if attempts are made to perfume indoor air, much more can be done with the room’s material, volume and structure – that which creates atmosphere. Air should always be light, while atmosphere can have any density. Architecture, wrote the Austrian architect Adolf Loos in 1925, is all about emotions. The architect’s task is to make these emotions precise.