The airtightness of building must be measured for the evaluation of building energy performance. To make up the reference airtightness value of wooden houses built in Korea, blower door test was carried out in the 36 houses. And, during the test, the causes of air leakage were inspected simultaneously. The result showed that the average of ACH50((air change per hour at air pressure difference 50Pa) measured from light timber frame houses was 3.5 h-1 and the post-beam construction was 5.1h-1. And, insulation with form of foams was advantageous in ensuring building airtightness than glass fiber batt. And, values below 1.5 h-1 of ACH50, threshold for application of artificial air change equipment, had appeared after 2010s. Also, the values varied according to who managed the building construction field. Although only one measurement of CLT(cross laminated timber) residential building could be obtained in 2016, the result showed good airtightness of building with 0.7 h-1.
This Illustrated Guide consolidates information on vaulted water-shedding roofs and flat waterproof membrane roofs that are capable of meeting R-30 or greater effective thermal performance when used on low- and mid-rise wood-frame buildings. The guide is intended to be an industry, utility, and government resource with respect to meeting this thermal performance level, while not compromising other aspects of building enclosure performance, including moisture management, air leakage, and durability.
Air leaks have a considerable impact on the energy load and durability of buildings, particularly in cold climates. In wood construction using cross-laminated timber (CLT), air leaks are most likely to be concentrated at the joints between panels and other elements. This study used simulations of heat, air, and moisture transfers through a gap between two CLT panels causing air leakage in winter conditions under a cold climate. A real leakage occurrence was sized to validate the simulations. The aim of this work was to assess the impact on the energy loads and the durability of an air leak, as either infiltration or exfiltration, for different gap widths and relative humidity levels. The results showed that infiltrations had a greater impact on the energy load than exfiltrations but did not pose a threat to the durability, as opposed to exfiltrations. Gap sizes in CLT may vary, but the effect on the energy load was sensitive to the leakage path in the rest of the wall. As expected, a combination of winter exfiltration and a high level of interior relative humidity was particularly detrimental.