Numerical performance investigation of decentralized ventilation compared to centralized ventilation system at a residential building: A case study in Norway

Abstract

A main goal of the study is to investigate whether decentralized ventilation (DV) systems can outperform typically centralized ventilation (CV) system in terms of energy while keeping indoor air quality at acceptable levels. And additional research questions regarded heat recovery function and placement of DV units within the apartment space. The question about modeling the DV units themselves within a Software, IDA-ICE was investigated. The placement of DV unit has been proposed. The advantages and drawbacks of using such systems were outlined and compared to centralized ventilation. The question of modeling DV units in building simulation software was raised and discussed. Results show that, given the chosen set of boundary conditions and model of DV, it offers the best performance energy-wise in the mild season. The differences are most visible during colder months when the heat demand is highest. A DV came out with slightly worse energy performance with low heat recovery unit (HRU) performance. The differences weren’t substantial and none of the analyzed systems met the TEK17 requirement for net delivered energy for residential buildings. No significant difference was shown regarding indoor climate indicators across systems. Seasonal energy analysis shows marginal differences between systems. HRU function showed significant energy-saving potential in cold seasons.