Dependence of measured specific air leakage rate (qE50) on envelope pressure differences and measurement position: a case study in an apartment building in winter conditions

Airtightness of the building envelope has become an important component in achieving ever stricter energy performance levels. However, airtightness measurements using blower door method are dependent on choices made by the specialist conducting the tests. One being the assessment of baseline pressure difference inside the building and position of the measurement equipment. Ideally, the test will be conducted without wind and stack effect which could disturb the envelope pressure measurements. Unfortunately, such conditions seldom exist, especially in colder climates. This increases the appeal of conducting apartment-wise measurements over whole-building measurements as it is far easier to comply with the ISO 9972. However, the apartment-wise method has a relatively random nature due to small share of actual building envelope. This paper investigates the effect of using different measurement positions and pressure levels on the airtightness measurement results. A 5-storey 15m tall residential building was used as a case study and measured as a whole and in select apartments. The results show that the variation caused by different choices of pressure levels, measurement positions etc caused relatively low variations and whole-building measurement should be preferred even if not all baseline and pressure level requirements are not met.

Study Of The Variability Of Air Leakage Rate Between In-Situ Tested and Laboratory Tested

The air leakage measured using the laboratory test of fenestration is important to gauge its initial performance and for certification. Field testing based on a statistical approach was carried out in this study on newly installed fenestration product to study the nature of distribution of air leakage measurements. The measured values from these tests were also compared to the laboratory tested value of the same product and to the values as suggested in field testing guidelines as provided in AAMA 502. Results indicate that field measured values at standard pressure difference follow a normal distribution with a mean and a variance. The results also show that while number of test results fall within a certain range of the laboratory value and the AAMA 502 stipulated value, there are number of values that are higher than them.

Study Of The Variability Of Air Leakage Rate Between In-Situ Tested and Laboratory Tested

The air leakage measured using the laboratory test of fenestration is important to gauge its initial performance and for certification. Field testing based on a statistical approach was carried out in this study on newly installed fenestration product to study the nature of distribution of air leakage measurements. The measured values from these tests were also compared to the laboratory tested value of the same product and to the values as suggested in field testing guidelines as provided in AAMA 502. Results indicate that field measured values at standard pressure difference follow a normal distribution with a mean and a variance. The results also show that while number of test results fall within a certain range of the laboratory value and the AAMA 502 stipulated value, there are number of values that are higher than them.

Study on Smoke Leakage Performance of Suspended Ceiling System

The key focus of the research is on the smoke leakage rate from suspended ceiling system, referencing CNS 15038 norm and its experimental principles to build a set of monitoring equipment for measuring air leakage rate and the provision of detailed assembly details for users’ reference. Through the real-size test chamber, the smoke insulation performance of the ceiling is studied. Targeting the different ceiling materials, ceiling panels dimensions, and construction methods, in keeping with the scientific principles of fluid mechanics, a total of 405 tests are carried out to come up with the means of appraising the leakage rate of ceiling panels of different sizes and materials. The study found that with the ceiling panel material quality being different, even if the ceiling size is the same, different leakage rates could occur. When the material quality of the ceiling panels is the same and the ceiling size is different, it is not that the larger the size of the panel, the greater the leakage rate, but the smallest leakage rate is caused by the largest panel and this is a very special phenomenon. This study also presents a leakage rate assessment table for entire ceiling panels, which will provide future calculations of the smoke leakage rate of the non-flame room, which can be extrapolated to assess the time of smoke decline and conducive for evacuation design. The apparatus has been proven to have proper leakage rate detection capability for the ceiling panels. In the future, the design principle of the extended system can be applied to the inspection and testing of smoke insulation capability of other fire prevention products. In turn, it can be estimated when the smoke has fallen to facilitate escape design.

Overview of large building testing in Baltic countries

The objectives of this paper are to review measurements of airtightness of 2 large building groups – middle size shops, and warehouses/distribution centres. The mean air leakage rate at 50 Pa pressure difference q50 was 1.04 m3/m2h and 1.35 m3/m2h for shops and warehouses respectively. Analysis of measurement results is valuable because it allows to make a conclusion about compliance of national and corporative construction airtightness norms with actual air barrier condition on a comissioning stage. In the concluding part of the study there are suggested ways to improve air barrier such as review of construction norms, implementation of a mandatory testing and quality control of a measurement.

Resilience of Canadian homes and small buildings to the effects of climate change - Risk of deterioration due to condensation within wall assemblies

The objective of this study was to assess the potential effects of climate change on the moisture performance and durability of typical Canadian wood-frame walls using hygrothermal simulations, with a particular attention to the risk of condensation. To reduce the risk of condensation, the National Building Code of Canada (NBCC) recommends a maximum air leakage rate of 0.10L/sm2 at 75 Pa in buildings with interior relative humidity not greater than 55%. This leakage rate was evaluated in five cities across Canada for a wood-frame wall having brick cladding, with and without outdoor insulation and both walls meeting the minimum insulation requirements given in NBCC. It is found that the risk of condensation will be reduced in the future in all 5 cities analysed. The reduction in the risk of condensation is slightly higher for the wall with no exterior insulation than for the wall with exterior insulation. This reduction in the risk of condensation means that the limit of 0.10L/(sm2) for building having a warm side relative humidity of less than 55% may be reconsidered in the future. There may however be some risks associated with the increase in rain in some cities.

Air Leakage of Joints Filled with Polyurethane Foam

Air leakage through the building envelope joints is usually one of the main reasons why airtightness targets are not achieved. The objective of this study was to analyse the air leakage of joints filled with polyurethane foam and its influencing factors. Wooden test specimens (54 in total) with planed, sawn and plastic-coated cavities and two cavity thicknesses were filled with three different polyurethane foams and tested according to standard EN 12114. The surface type and thickness of the joint had a significant effect on the air leakage of joints filled with polyurethane foam. In laboratory conditions, a consistent and very low air leakage rate was obtained with planed timber surfaces. Joints with plastic-coated and sawn timber surfaces performed worse, on average, by a factor of two or more and contributed to very variable airtightness, with up to 28% and 50% of the test specimens failing the airtightness testing. On the basis of the high ‘failure rate’, polyurethane foam may classify as a not completely trustworthy solution in guaranteeing the airtightness of construction joints. A comparison of estimated and previously measured overall airtightness of an entire building envelope showed dependency on ‘failure rate’ rather than on average measured leakage rate.

Investigation of Influencing Factors on Air Leakage of Canadian Dwellings

Air leakage is one of the main influencing factors in buildings’ thermal performance. The adverse effects of poor air leakage include higher energy costs, consumption in space heating and cooling, poor thermal comfort, corrosion, and the growth of molds due to air leakage induced condensation. The main objective of this study is to investigate the characteristics of air leakages of Canadian homes related to construction methods, age, size and climatic zones. The air leakage test results of 226,000 dwellings in three provinces of Canada were analyzed. Statistical analysis was utilized to compare the mean of air leakage with respect to different factors. Generally, the air leakage decreased by 40% in the period from 1960 until 2018, which has shown a remarkable effect of new construction techniques on air leakage. Investigations also indicated that the average air leakage rate of homes constructed by using the onsite technique is approximately 25% to 60% higher than those prefabricated in modular or panels, varying with respect to the workmanship and construction quality control. This study concluded that the prefabricated construction techniques could decrease the air leakage rate significantly, which will have a remarkable effect on buildings’ thermal performance as well as home’s heating and cooling costs. The findings contribute to estimating the effects of influencing factors on air leakage, also it is useful in performance simulations, HAVC sizing and energy management. And recommend the use of the prefabricated in modular or panel’s construction method to achieve better and acceptable air leakage performance.