The most effective way to ventilate is found

According to researchers at the University of Debrecen, the best way to ventilate offices in winter is to use machines to let fresh air in where it is most useful. The scientific paper summarising the research results from the Faculty of Technology was awarded the Publication Prize of the Gróf Tisza István Foundation for the University of Debrecen.

In the United States and the European Union, almost 40 percent of all winter energy consumption is spent on building maintenance. The European Union has therefore been calling for better insulation since 2000, and in the early 2010s it set the goal of nearly zero-energy buildings.

- However, workers in such places started to complain that the "air inside is stagnant", the exhaled breath and carbon dioxide reduce concentration and the quality of work deteriorates. Ventilation through open windows allows fresh air to enter quickly, but the heat escapes. Therefore, modern buildings should be equipped with mechanical ventilation, which has the great advantage that just as much air can be brought in as is needed, and in addition, dust and most of the pollen can be filtered out, and this air can even be preheated," the associate professor of the Department of Building and Facilities Engineering at the Technical Faculty of the University of Debrecen (DE MK) told   

Tünde Kalmár added: research shows that one of the most important things for a person sitting in an office to feel good is to have 30 cubic metres of fresh air per person per hour and a temperature as close as possible to 24 degrees Celsius. Drafts should also be prevented from forming.

In 2015, DEnergia, the Energy Research Group of the University of Debrecen, developed a personal ventilation device called ALTAIR. The device is used to circulate fresh air in the immediate vicinity of the person sitting at their desk. This means that considerably less air is needed than the volume described above,  which means less cleaning, less transport and less energy consumption is needed," he stressed.
Tünde Kalmár recalled that during the Covid epidemic, offices, and shops often tried to protect their employees using Plexiglas sheets. The main aim of their research was to compare the cleanliness of the air around the person sitting at their desk when using conventional ventilation methods and the personal ventilation system that they had developed, when Plexiglas panels are used. The measurements were carried out in the special laboratory for Indoor Environmental Quality at DE MK. A total of 50 measurements, each lasting 2 hours, were taken, during which the amount of carbon dioxide in the fresh air let in, in the immediate vicinity of the worker and in the exhaust air was also measured," said Tünde Kalmár.

- The results were evaluated and the efficacy of ventilation was determined in each case. We also created a 3D model of the test site and visualised the air flow in the space using ANSYS software. This research also proved that the ventilation efficiency using ALTAIR equipment is higher than that of conventional ventilation methods. With ALTAIR, fresh air is delivered to the immediate vicinity of the seated worker from the front and from the sides, possibly alternating between the two. In this case, the test subjects reported that they stayed fresh and did not feel drafty. In addition, ventilation became much more cost-effective. The widely used air blowing from the ceiling is nowehere near as effective," summarises the experience of the DE MK associate professor.
In addition to Tünde Kalmár, Ferenc Kalmár, Professor at the Faculty of Technology, and Associate Professor Ferenc Szodrai participated in the research. The scientific article presenting the results, published in English in the prestigious international journal Energy, was awarded the Publication Prize of the Gróf Tisza István Foundation for the University of Debrecen, which maintains the University of Debrecen.

Press Centre - OCS