Authors:Peter Kapalo, Florin Domnita, and Jan Lojkovics
The aim of the paper is to determine a methodology for calculating the needed airflow rate (including fresh air) in an occupied room, based on carbon dioxide measurement and calculation, in order to maintain the comfort indoor air quality. The calculated airflow rate should optimize the investment and the operating costs of HVAC equipment. In the work there are analyzed the calculation methods used to determine the ventilation airflow rate. It is presented the methodology for calculating the ventilation airflow rate for a room with people inside by using the measured values of carbon dioxide concentration. The connection between carbon dioxide concentration and ventilation airflow rate is verified by experimental measurements. This methodology is applicable in Slovakia because it complies with all current standards. The result obtained by using this calculation method is almost the same with that achieved from experimental measurements. To confirm the results, it is presented a case study of an office with occupants, in which the ventilation airflow rate calculation method is applied.In the article only a part from the total work is presented. The experimental measurements were carried out from 2011 to 2014. Approximately 54 measurements were covering total days or weeks. The following factors have been measured: indoor air temperature, outdoor air temperature, relative humidity of indoor air, relative humidity of outdoor air, concentration of CO2 in indoor air, concentration of CO2 in outdoor air, pressure difference and wind velocity. Ventilation by infiltration was calculated based on these factors using several methodologies. The methodology of measurement is not subject to the article. In this article only one aspect is investigated: CO2 concentration.