Audit of low-tec ventilation systems in office buildings

Abstract

This study examined ten office buildings with simplified ventilation systems. The methodology comprised a user survey, the calculation of embodied energy in terms of greenhouse gas (GHG) emissions and measurements in four of the buildings. The survey shows that in winter 35 % of the participants are satisfied with the ventilation system, 45 % are moderately satisfied (N = 553). In summer the satisfaction rate is slightly lower with 25 % satisfied and 33 % moderately satisfied (N = 458). The measurements however show that the indoor air quality regarding CO2 (IDA (CO2) in all four buildings is better in summer (all buildings are class I), than in winter (all buildings: class II). Regarding indoor environment quality and temperature (IEQ (RT)) in winter all buildings are classified cathegory II, in summer the buildings vary between class I and III, with most of them in class II. GHG calculations show that by reducing HVAC it is possible to save up to 70 % of the embodied GHG emissions used for HVAC. By reducing ventilation alone, over 50 % of the embodied GHG emissions for HVAC can be saved.