Energy saving is strongly affected by air leakages which also influence IAQ. Particularly, several studies show that the air-tightness energy losses contribution of the windows ranges up to 40%, with a value 15% higher than that predicted by the ASHRAE. Such values confirm the high influence of the windows and the possibility to significantly reduce heat losses by ventilation by only operating on the windows. Furthermore, inefficiency of windows is often combined with unsealed rolling-shutter boxes and a bad mounting of the window. On the other hand, in the ventilation system design, air- tightness is generally neglected and included in the air change rate due to mechanical ventilation system. Such a practice increases energy consumptions and improves indoor air quality; on the contrary, a wrong assessment of the contribution of air infiltration can lead to the over-sizing of the ventilation system in the design phase. To better understand the influence of the windowed components on the air change rate under a pressure difference value of 50 Pa, the class of air-tightness should be assessed for each tested component, in compliance with EN 12207 Standard, and as a function of: (i) the type of material, (ii) the presence of the seal; (iii) the type of closure; (iv) the sealing of the door; (v) the maintenance condition. In this paper, the Authors present the first experimental results of air-tightness measurements carried out in three residential buildings in which windows retrofit consisted in sealing gasket on the wooden window and replacing them with PVC or aluminum windows. Moreover, the effectiveness of investigated windows retrofits has been estimated in terms of energy saving by using the fan pressurization method. Obtained results showed a high variability of the air permeability although windows used for retrofit were characterized by lowest permeability values according to EN Standard 12207. This was mainly due to the poor care devoted during the windows installation and the lack of tests.
Experimental analysis of different windows retrofits on building’s air-tightness: first results
DELL'ISOLA, Marco;FICCO, Giorgio;
2016-01-01
Abstract
Energy saving is strongly affected by air leakages which also influence IAQ. Particularly, several studies show that the air-tightness energy losses contribution of the windows ranges up to 40%, with a value 15% higher than that predicted by the ASHRAE. Such values confirm the high influence of the windows and the possibility to significantly reduce heat losses by ventilation by only operating on the windows. Furthermore, inefficiency of windows is often combined with unsealed rolling-shutter boxes and a bad mounting of the window. On the other hand, in the ventilation system design, air- tightness is generally neglected and included in the air change rate due to mechanical ventilation system. Such a practice increases energy consumptions and improves indoor air quality; on the contrary, a wrong assessment of the contribution of air infiltration can lead to the over-sizing of the ventilation system in the design phase. To better understand the influence of the windowed components on the air change rate under a pressure difference value of 50 Pa, the class of air-tightness should be assessed for each tested component, in compliance with EN 12207 Standard, and as a function of: (i) the type of material, (ii) the presence of the seal; (iii) the type of closure; (iv) the sealing of the door; (v) the maintenance condition. In this paper, the Authors present the first experimental results of air-tightness measurements carried out in three residential buildings in which windows retrofit consisted in sealing gasket on the wooden window and replacing them with PVC or aluminum windows. Moreover, the effectiveness of investigated windows retrofits has been estimated in terms of energy saving by using the fan pressurization method. Obtained results showed a high variability of the air permeability although windows used for retrofit were characterized by lowest permeability values according to EN Standard 12207. This was mainly due to the poor care devoted during the windows installation and the lack of tests.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
