Influence of building airtightness on the internal thermal comfort and air quality in the single family house

Abstract

The knowledge of the air exchange and building air-tightness is an indispensable source of information, both on the design and operation stage of the building use. Properly functioning ventilation system affects significantly internal thermal comfort and internal air quality. Infiltration of air determines the proper functioning of the gravitational ventilation, still the most commonly used system in Polish single-family housing. However, the most popular and easy to measure parameter: building airtightness (n50), does not specify the real air exchange in the actual climatic conditions. The real air flow rate may be determined with much more troublesome gas tracing method. Air flow rate, n, is in this method obtained from the decaying curve of gas concentration after injection of tracer gas into the building. This paper presents the results of the airtightness measurements conducted in a single family house with natural ventilation. Both, n 50 parameter and building air flow rate n have been measured. The results of the measurements were used as a model calibration tool in the annual computational simulations carried out in the Design Builder program for the Polish climatic conditions. Based on these simulations the authors determined the influence of building airtightness on the internal thermal comfort and the potential scenario of its control.

Parametric Study of Air Infiltration in Residential Buildings—The Effect of Local Conditions on Energy Demand

“…Some analyzes [8][9][10] show that infiltration is responsible for even 13%-30% of energy losses during the heating season and 4%-14% in the cooling season, while others [11] found that the impact was more significant (even up to 50%). Moreover, airtightness is an important indicator of the building quality, as it affects not only the thermal parameters of the building but also the indoor air quality [12,13], the level of thermal comfort in new [14] and modernized buildings [15], and the long-term durability of buildings [16].…”

Modelling building infiltration using the airflow network model approach calibrated by air-tightness test results and leak detection

“…2,3 Airflow is directly related to building quality, 4 because it influences the transport of heat and moisture and affects the indoor environment, as well as the durability of the building enclosure 5 and CO 2 emissions. 6 Improved building air-tightness leads to lower air infiltration, 7 better thermal comfort levels, 8,9 the reduction of the cooling load and heat losses in buildings, 10,11 and the reduction of CO 2 concentration in rooms. 12 In new buildings, after 2005, about 25% of the total energy demand are losses related to the heating of air flowing through the building envelope in the place of leaks, such as cracks, crevices and other unintentional openings.…”