English

Thermal comfort is a subjective term, closely related to the sensation of warm or cold for the occupants, defining the state of mind of humans that expresses satisfaction with the surrounding environment. Since we spend more than 90% of our time inside buildings or vehicles, achieving a good thermal quality of this enclosed environment is vital. An optimal thermal comfort prediction can lead to „bien-être”, efficiency in our work, unaltered health and even energy economy.

The need for thermal comfort and clean air for occupants in buildings or vehicles is vital since we spend more than 90% of our time inside these enclosed environments. Worldwide, current directions of the leading powers are oriented towards the reduction of the energy consumptions and HVAC systems make no exception. Personalized Ventilation (PV) applied to buildings may represent a solution to this problem. The main idea of PV is to provide clean air close to the face of each occupant and to improve thermal comfort in his microenvironment.

The existence of air leakages in a building has been very clearly stated as an important reason for energy loss. The decrease in the efficiency of the mechanical ventilation has also been clarified. The global demand for achieving nearly zero-energy buildings makes the uncontrolled leakage paths even more undesired. Despite the fact that steady state measurements of in- and exfiltration rates offer a simple and easy way of estimating the airtightness level of an eclosure, a supplement to those methods might be imposed.

The Spanish Technical Building Code is one of the three royal decrees that were approved in Spain as a consequence of the transposition of the European Directive on the energy performance of buildings (2002/91/EU) [1]. One basic document of the Technical Building Code deals with the limitations in the energy demand of buildings. Nowadays, due to the recast of the European Directive on the energy performance of buildings (2010/31/EU) [2], a revision process of the current regulations has begun, starting with the Technical Building Code, with its first revision envisaged for 2012.

The new Nicosia Town-hall is a very particular building. On the site where it is built, important antiquities were discovered during the first day of construction and the whole design was completely modified to fit to the new situation. The archaeologists continued to excavate 2/3 of the entire site and created an archaeological park in the centre of the town. The building area was constraint to the remaining land, and co-exists with the uncovered findings.

Low energy buildings, being highly insulated, are subject to important overheating risks. Thermal simulation as well as experimental studies have shown the large potential of ventilative cooling. One barrier against this approach is the difficulty of evaluating air flows. Appropriate calculation methods and characterization of openings are needed, so that these systems can be dealt with in design, regulation and certification tools.

Natural ventilation and dynamic temperature simulation of buildings was until now a priviledge of highly skilled building physicists. Combined simulation of both is even rarer. 

From January 1st 2013 on, the French energy performance regulation will demand that the airtightness level is justified and that airtightness of a building should be below 0,6m3/h/m² at 4Pa for single family housing and 1m3/h/m² for multi-family dwellings, resulting into an important growth in the airtightness market. It is the role of the State to accompany this market evolution and to supervise the quality of airtightness measurements used for the EP calculation. This is why it has been decided that there are two possibilities to justify the airtightness level of a building.

The efficiency of air-to-air heat recovery ventilation units is of great importance for EP calculations (energy performance of buildings) throughout Europe. Efficiencies compared on a reliable basis are also crucial for contractors and installers of such systems.

DIN 4108-7 requires a limit of q50 ≤ 3.0 m³/m²h for the air permeability of large buildings. Even stricter limits with respect to q50 can be found at DGNB [German Sustainable Building Council] and in the Swiss MINERGIE Standard.
It is the objective of this presentation to develop awareness of this topic in the audience and to give recommendations as to which limits can be applied to new building projects.