Ventilation systems with local recirculation diffusers

Improving indoor air quality while simultaneously minimizing the consumption of ventilation and air conditioning systems has received increased attention in recent years (Joo et al. (2012) [1], Le Dreau et al. (2013) [2], Rackes and Waring (2014) [3], Han et al. (2014) [4], Van den Bulck et al. (2013) [5], Ngoc Quang et al. (2013) [6], Naumov and Kapko (2013) [7], Naumov et al. (2013) [8]). The standard thermal protection level of outdoor enclosure structures has increased significantly (Rulebook of the Russian Federation 50.13330.2012 Thermal protection of buildings [9]). In addition, office buildings are characterized by considerable heat emissions during their operation. Using traditional solutions for heating and ventilation in the heating period results in wasted energy: outdoor air is heated to the desired temperature in the air heater of the supply ventilator unit (usually equal to the temperature of the room air); also, the air conditioning system consumes energy to produce cold air to address the internal heat emissions. The heat consumption in ventilation systems can be reduced by recirculation. This article presents a discussion of the advantages and disadvantages of different ventilation systems, including the ventilation scheme with local recirculation diffusers developed by the authors for rooms with considerable heat emissions. Based on the analysis of the life cycle cost, the article presents an assessment of the marginal cost of one local recirculation diffuser for these systems.