Standards related to calculation methods used in building energy performance simulation tools usually impose constant volumetric heat capacity of air. However, this simplification may result in errors if the actual conditions differ from the assumptions made. The paper presents the problem of dry air density and specific heat capacity variation and their influence on calculated energy use for space heating in a multifamily building. The monthly calculation method of PN-EN ISO 13790 was used. Simulations were performed in five cities, each in one climatic zone according to PN-EN 12831. Variation of the air density caused by air temperature and elevation resulted in differences in calculated heating demand from -4.5% to 4.5% in relation to that at constant volumetric heat capacity assumed in PN-EN ISO 13790.
Nov 6, 2023
Jun 10, 2022
|Piotr Michalak, 2020, Ventilation heat loss in a multifamily building under varying air density
|Nov 6, 2023
Michalak, Piotr Grygierczyk, Stanisław