Paper Conference

Proceedings of Building Simulation 2021: 17th Conference of IBPSA


Impact of 2-zone recirculation on IAQ and energy performance of a demand controlled MEV system

Ivan Pollet 1, Bavo De Maré 1, Steven Delrue 1, Frederik Losfeld 1, Jelle Laverge 2, Samuel Caillou 3
1 Research, Renson Ventilation, Waregem, Belgium
2 Building Physics Research Group, Ghent University, Gent, Belgium
3 Belgian Building Research Institute (BBRI), Limelette, Belgium

Abstract: Demand controlled mechanical extract ventilation (MEV) systems combined with natural air inlets and central mechanical ventilation systems with heat recovery (MVHR) are usually used in the Belgian residential sector to control IAQ. In order to balance the supply and extract air flow rates of MVHR systems, air can be transferred mechanically between habitable rooms to reduce the supply capacity of the unit, called a 2-zone recirculation or cascade system. A similar approach can be applied to balance MEV systems by transferring air from the night to the day zone, while reducing natural air supply capacity. Besides, the performance of MEV systems with additional indirect mechanical extraction from the rooms via the hall was compared with an MEV system with direct extraction from habitable rooms, as already widely used in the Belgian market. Dynamic simulations were performed on several ventilation system configurations (without or with open kitchen, natural or mechanical indoor air transfers, with or without air supply in the living room) to analyse the impact on IAQ (CO2, RH) and energy efficiency EE (heat losses) of MEV systems. Results pointed out that a similar and even better ventilation performance can be achieved by applying demand controlled mechanical air transfer between the rooms, compared to an MEV system with direct extraction from the habitable rooms.
Keywords: air recirculation, MEV, demand controlled ventilation
Pages: 2586 - 2591