Indoor thermal environment, air exchange rates, and carbon dioxide concentrations before and after energy retro fits in Finnish and Lithuanian multi-family buildings

Virpi Leivo; Tadas Prasauskas; Liuliu Du; Mari Turunen; Mihkel Kiviste; Anu Aaltonen; Dainius Martuzevicius; Ulla Haverinen-Shaughnessy

doi:10.1016/j.scitotenv.2017.11.227

Indoor thermal environment, air exchange rates, and carbon dioxide concentrations before and after energy retro fits in Finnish and Lithuanian multi-family buildings

Sci Total Environ. 2018 Apr 15:621:398-406. doi: 10.1016/j.scitotenv.2017.11.227. Epub 2017 Nov 27.

Authors

Virpi Leivo¹, Tadas Prasauskas², Liuliu Du³, Mari Turunen³, Mihkel Kiviste⁴, Anu Aaltonen⁴, Dainius Martuzevicius², Ulla Haverinen-Shaughnessy³

Affiliations

¹ Tampere University of Technology, Department of Structural Engineering, Tampere, Finland. Electronic address: virpi.leivo@tut.fi.
² Kaunas University of Technology, Department of Environmental Technology, Kaunas, Lithuania.
³ National Institute for Health and Welfare, Department of Health Protection, Kuopio, Finland.
⁴ Tampere University of Technology, Department of Structural Engineering, Tampere, Finland.

PMID: 29190562
DOI: 10.1016/j.scitotenv.2017.11.227

Abstract

Impacts of energy retrofits on indoor thermal environment, i.e. temperature (T) and relative humidity (RH), as well as ventilation rates and carbon dioxide (CO₂) concentrations, were assessed in 46 Finnish and 20 Lithuanian multi-family buildings, including 39 retrofitted case buildings in Finland and 15 in Lithuania (the remaining buildings were control buildings with no retrofits). In the Finnish buildings, high indoor T along with low RH levels was commonly observed both before and after the retrofits. Ventilation rates (l/s per person) were higher after the retrofits in buildings with mechanical exhaust ventilation than the corresponding values before the retrofits. Measured CO₂ levels were low in vast majority of buildings. In Lithuania, average indoor T levels were low before the retrofits and there was a significant increase in the average T after the retrofits. In addition, average ventilation rate was lower and CO₂ levels were higher after the retrofits in the case buildings (N=15), both in apartments with natural and mixed ventilation. Based on the results, assessment of thermal conditions and ventilation rates after energy retrofits is crucial for optimal indoor environmental quality and energy use.

Keywords: Air exchange rate; CO(2) concentration; Energy retrofit; Multi-family buildings; Thermal environment.