INTRODUCTION OF HYBRID VENTILATION SYSTEMS OF DWELLING BUILDINGS IN LATVIA

Until the end of 90-ties all dwelling buildings in Latvia were equipped with mandatory natural ventilationsystems with stack effect. Nowadays in many cases in dwellings there are only exhaust mechanicalventilation but air tight windows prevent natural air intake. Such systems result in bad IAQ. The using ofregular mechanical inflow - outflow ventilation systems in dwelling buildings is limited by different factors- such as high noise level during operation time, limited buildings area and high construction expenses.The operation of mentioned ventilation systems is complicated and inefficient.In order to improve the existing situation with ventilation of dwelling buildings some of new moderntechnical decisions were introduced. One of these decisions is the implementation of hybrid ventilation.The paper is devoted to the trial implementation of hybrid ventilation systems in dwelling buildings inLatvia. The comparison of indoor air in buildings equipped with hybrid ventilation system and in buildingswith natural ventilation was done as well.The paper gives theoretical principles of the hybrid ventilation system, describes advantages andshortcomings of the ventilation systems selected for the trial implementation.