## 1 Introduction  
The indoor environmental quality (IEQ) depends on both indoor air quality (IAQ) and human comfort (thermal, visual, acoustic). A poor IEQ could precondition different discomorts and health problems that result in short or and long-term absence from work and decreased productivity [1; 2; 3]. [PERSON] et al. [4] reported that in more than 40% of enclosures people complain from the comfort or health-related issues. The situation is worsening in schools, where the occupation density is 1.8-2.4 m\({}^{2}\)/person, compared to 10 m\({}^{2}\)/person in offices [5]. Improving the working environment and related costs can be offset by better productivity [6] and overall comfort [7]. There is a need for studies on the assessment of ventilation strategies in terms of their efficiency while aiming to provide the comfort of the occupants [8; 9; 10]. According to ISO 7730:2005 [11], the thermal environment in an indoor space can be assessed in 3 categories. Two factors determine each category: the thermal state of the body, evaluated by the Predicted percentage of dissatisfied (PPD) index, and the local discomfort. One of the indices for local discomfort is the draught rate (DR). The achievement of air distribution without draught is one of the goals of the ventilation methods for indoor spaces. The high air velocity in the occupied zone could be easily perceived as draught that provokes thermal comfort dissatisfaction and complaints. Various studies assessed DR as a part of the evaluation of the thermal environment. [PERSON] et al. [12] investigated test buildings with a variety of wall envelops and different heating/cooling systems. They calculated the local discomfort due to DR for 2-hour periods and the value of 40% for local turbulence intensity. [PERSON] et al. [13] determined DR and thermal asymmetry as the most important factors for complaints among the cashiers in the studied supermarket. However, the study could not prove the statistical significance of DR on the overall thermal sensation of the occupants. [PERSON] et al. [14] investigated the winter IAQ and thermal comfort in new secondary schools, applying ISO 7730:2005 [11]. They have found out that both mechanical and hybrid ventilation systems caused problems with draughts (the draught risk exceeded 15%). On this basis, the authors suggested a more careful design of the ventilation systems in classrooms. Recently, [PERSON] et al. [15] reported their assessment of the draught and thermal comfort in an office building. It was found that DR was below 10% in heating and transient period measurements, but the risk of draught was assessed for the intensive cooling mode. In a later paper [16], it was concluded that avoiding fan coil units for cooling would not guarantee better thermal comfort for the occupants without draught complaints. Numerical studies that involved DR assessment were also performed. [PERSON] et al. [17] used numerical predictions to evaluate the thermal comfort of people in an indoor swimming pool. Though it was concluded that in a significant part of the pool the thermal comfort conditions were not reached, the authors reported that there was no draught risk. [PERSON] and [PERSON] [18] investigated a naturally ventilated plan office, applying a numerical analysis of local thermal comfort. They reported an effect of the high outdoor wind speed and low air temperature on the increment of the indoor DR.  
Several other studies [19; 20; 21; 22; 23; 24] identified DR to be the main cause of thermal discomfort even in the case that other characteristics of the thermal environment have been within the standard limits. Therefore, the correct determination of DR is of crucial importance, and each case study may help to improve the knowledge of its evaluation. The assessment of the DR is performed, following the approach of [PERSON] et al. [25], implemented in ISO 7730:2005 [11]. Attempts for different calculation of DR also exist, like the innovative method in [26], developed for semi-outdoor spaces.