Air Tightness Testing Research Articles

Examining approaches to investigating the United Kingdom’s existing building fabric in the pursuit of net zero targets

Purpose The purpose of this study is to investigate and analyse the potential of existing buildings in the UK to contribute to the net-zero emissions target. Specifically, it aims to address the significant emissions from building fabrics which pose a threat to achieving these targets if not properly addressed. Design/methodology/approach The study, based on a literature review and ten (10) case studies, explored five investigative approaches for evaluating building fabric: thermal imaging, in situ U-value testing, airtightness testing, energy assessment and condensation risk analysis. Cross-case analysis was used to evaluate both case studies using each approach. These methodologies were pivotal in assessing buildings’ existing condition and energy consumption and contributing to the UK’s net-zero ambitions. Findings Findings reveal that incorporating the earlier approaches into the building fabric showed great benefits. Significant temperature regulation issues were identified, energy consumption decreased by 15% after improvements, poor insulation and artistry quality affected the U-values of buildings. Implementing retrofits such as solar panels, air vents, insulation, heat recovery and air-sourced heat pumps significantly improved thermal performance while reducing energy consumption. Pulse technology proved effective in measuring airtightness, even in extremely airtight houses, and high airflow and moisture management were essential in preserving historic building fabric. Originality/value The research stresses the need to understand investigative approaches’ strengths, limitations and synergies for cost-effective energy performance strategies. It emphasizes the urgency of eliminating carbon dioxide (CO2) and greenhouse gas emissions to combat global warming and meet the 1.5° C threshold.

Exploring the Role of Airtightness for Achieving Carbon Neutrality in Canadian Residential Buildings: A Streamlined Life Cycle Assessment

This study delves into the relationship between airtightness levels and the entire life cycle carbon emissions of buildings across diverse Canadian climates. With the 2020 update of the National Energy Code of Canada for Buildings, whole-building airtightness testing was introduced as an option, prompting discussions on its mandatory nature. Using a net zero target, our assessment unfolds in two phases. Initially, we employ three-dimension (3D) modeling in Revit to replicate a typical Canadian detached house’s architectural features and material compositions. Subsequently, the model was imported into One Click life cycle assessment (LCA) to set parameters such as lifetime, gross interior area, and annual electricity consumption. Our analysis is bifurcated into assessing climatic conditions in Edmonton, Toronto, and Vancouver, alongside examining code-specified airtightness levels. We compared annual energy loss per unit area at varying airtightness levels accounting for the general deterioration of airtightness in new buildings during the pre-service phase to pinpoint the optimal airtightness value (ACH50) during the design stage. The subsequent phase evaluated increased carbon emissions from material replacement to meet this optimal airtightness condition and passive energy savings. Findings underscore that designing airtightness to an ACH50 value of 1.0 is the most energy-efficient. Comparative analysis reveals that achieving carbon neutrality solely through increased envelope airtightness and passive energy savings, is viable in Edmonton (18.4 years) owing to regional energy source disparities. In contrast, Toronto and Vancouver necessitate active energy-saving devices to attain carbon neutrality over the design lifetime.

Examination of the metallization behaviour of an ABS surface

ABSTRACT The main scope of this work is the metallization of high density Acryonitrile Butadiene Styrene (ABS) surfaces for aerospace applications. Originality and main focused area of the study is to grasp the mechanism of physical properties of the surface and the effect of wet chemical processes on the surface of the ABS substrate. After surface sensitization and metallization with nano-sized ions, the polyurethane surface is metallized and nickel (Ni) coated with electroless and elecrolytic Ni plating processes. The ultimate goal of these advances is the production of composite lay-up tools for the production of primary and secondary composite aircraft parts from nanoscale to macro level. Composite lay-up tool requirements of the aerospace industry include a minimum thickness of 5 mm, acceptability of airtightness testing and reduced surface roughness. Results show that increasing current density adversely affects the surface morphology and metallization processes enhance the surface conductivity of the foam.

An investigation into the efficacy of the pulse method of airtightness testing in new build and Passivhaus properties

An investigation into the efficacy of the pulse method of airtightness testing in new build and Passivhaus properties

Energy and emissions effects of airtightness for six non-residential buildings in Canada with comparison to contemporary limits and assumptions

Building air leakage is often a significant contributor to the energy consumption of a building and is difficult to characterize. Unlike the thermal performance of building envelope components, the high variability of airtightness of building assemblies and their interfaces makes air leakage of buildings difficult to predict. This publication describes the process and results for identifying leakage rates and locations within six non-residential buildings using airtightness testing, specifically six commercial buildings. Infrared (IR) scanning was used to visualize locations of air leakage in the building envelope. The energy and emissions effects from the measured performance were quantified and compared to the assumption in the relevant Canadian building code.The air leakage rates for all buildings tested in this work were less than the ASHRAE 90.1 standard limit of 2.0 L·s−1 m−2 @ 75 Pa, while three were less than the Air Barrier Association of America (ABAA)/United States Army Corps of Engineers (USACE) standard limit of 1.25 L·s−1 m−2 @ 75 Pa, and two were less than the National Energy Code of Canada for Buildings (NECB) assumption of 1.5 L·s−1 m−2 @ 75 Pa (a different area normalization is used for the NECB). The effects of airtightness on energy use intensity and annual operational emissions were quantified and found to be substantial and varied. The incremental energy use intensity ranged from a reduction of 47 kWh/m2ᐧyear to an addition of 64 kWh/m2ᐧyear.The most common location of leakage is between connections of building assemblies, especially the roof wall connection, and building components, particularly doorways, as well as at various envelope penetrations, such as for pipes and ventilation inlets/exhausts. The process of testing was documented and showed that the use of currently-available commercial equipment enables tests for typical small to medium-sized commercial/non-residential buildings to be completed efficiently. The results showed there is notable variation in airtightness levels between buildings and there are opportunities for improvement.

The impact of wind upon the Pulse technique measured airtightness of a detached dwelling

The novel Pulse technique measures the building airtightness in a dynamic approach, involving a low-pressure pressurisation process, typically in 1–10Pa. It is known that the wind effect is one of the main sources of uncertainty for airtightness testing. The literature review revealed that the wind impact on measuring building airtightness has been explored in relation to the steady pressurisation method (i.e., the blower door), while there is limited research investigating the validity of the Pulse measurement under various natural wind conditions. In this study, in total, 423 Pulse tests were performed to measure the building airtightness of a five-bedroom dwelling located at the University of Nottingham, UK, under natural wind conditions. The viability of the Pulse technique for delivering airtightness measurements under different wind conditions was assessed, including the impacts of the wind speed and the wind direction on the Pulse measurements. Based on the measured air leakage rates, the threshold of maximum wind speed that led the Pulse measurements to have repeatability greater than ±10% is 5.0 m/s at 2.2 m above ground level (i.e., approximately equivalent to the meteorological wind speed of 7.9 m/s). On the other hand, the directional wind study showed that at lower wind speeds, the wind direction has a lesser influence on the Pulse measurement than the wind speed itself. Practically, multiple Pulse tests are recommended for minimising the wind impact on building airtightness measurement when adverse wind conditions are present.

Design of Integrated Airtight Testing Device for Certain Aircraft

According to the airtight pressurization principle of fuel, environmental control, engine oxygen replenishment and other systems of a certain type of aircraft, a set of comprehensive airtight detecting device is designed. The device is composed of a platform body, an instrument panel part, a switch control panel part, an air-conditioning system, an air-tight accessory, a connecting hose and other parts. It can test the airtightness of every system of the aircraft, and is small in size and simple in operation. It can be applied to all series of the aircraft of the Air Force. Through the military test, the device can meet the requirements of airtightness testing, shorten the preparation time of aircraft maintenance, and improve the efficiency of aircraft maintenance support.

Development of the selective pressure neutralization method – An air tightness test method for exterior pressure boundary characterization in high-rise residential buildings

This paper presents a novel method for characterizing the exterior envelope air tightness of high-rise multi-unit residential building suites, the “Selective Pressure Neutralization” (Selective PN) method. Through the neutralization of air flow across the corridor-suite pressure boundary, this method can improve accuracy compared to the typically implemented “Whole Suite” method, while halving the time and equipment requirements of on-site testing compared to the Pressure Neutralization method. A CONTAM model was developed using field data from eight case study suites and then used to simulate the effectiveness of the proposed method in fourteen suite configurations. Sensitivity study simulations were also carried out where individual suite pressure boundary air tightness characteristics were varied. The case study results showed average absolute exterior boundary characterization errors of 16% and 51% for the Selective PN and Whole Suite methods, respectively. The sensitivity study results showed that the Selective PN method meets or exceeds the accuracy of the Whole Suite method by up to 78% in buildings with leakier exterior boundaries, like those in buildings with punched windows (as opposed to window wall configurations). Thus, the Selective PN method shows promise as an alternative air tightness testing method.

Survey on the Indoor Thermal Environment and Passive Design of Rural Residential Houses in the HSCW Zone of China

Despite their high energy consumption, rural residential houses in the hot summer and cold winter (HSCW) zone still have a generally poor indoor thermal environment. The objective of this study was to understand the current status of the indoor thermal environment for rural residential houses in the HSCW zone and analyze its cause in order to develop some strategies for improvement through passive design of the building envelope. Face-to-face questionnaires and interviews, air-tightness testing, and temperature and humidity monitoring were conducted to understand the building envelope, energy consumption, and indoor thermal environment. Then, some passive design strategies were simulated, including the application of functional interior materials such as hygroscopic and phase change materials. An overall passive design for the building envelope can increase the room temperature by 3.6 °C, reduce the indoor relative humidity by 12% in the winter, and reduce the room temperature by 4.4 °C in the summer. In addition, the annual energy-saving rate can reach ~35%.

Multifunctional testing system design for varicose vein therapy apparatus

Varicose veins of lower extremity can be treated effectively with varicose vein therapy apparatus. In order to ensure its therapy effect, it is necessary to test the air tightness of pneumatic circuit and other related performance parameters. The traditional manual testing method has some problems, such as large error, low efficiency and so on. This paper developed a multifunctional testing system based on LabVIEW software to overcome these shortcomings. The system is a combination of software and hardware, which can realise key components calibration, pneumatic circuit air tightness testing, gasbag pressure-resistance performance testing, pressure sensor performance testing and air pump performance testing. The multifunctional testing system realises the goal of automated human-computer interaction testing, which has a bright future in the aspects of application prospect.

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.

Inferring the as-built air permeability of new UK dwellings

PurposeCompulsory airtightness testing was introduced for new dwellings in England and Wales in 2006 and in Scotland in 2010 to ensure that they are constructed according to design air permeability targets. These targets are set to limit heat loss through air infiltration. Previous work examining the large Air Tightness Testing and Measurement Association (ATTMA) data set of UK airtightness test data suggested that, in a proportion of dwellings, the targets were being met by post-completion sealing as opposed to airtight construction, but did not quantify the prevalence of this practice. The paper aims to discuss this issue.Design/methodology/approachIn this paper, the distribution of as-built airtightness and the proportion of dwellings undergoing post-completion sealing are estimated from the ATTMA data set covering 2015–2016. This is carried out by Bayesian statistical modelling, using the data set of recorded test results and a modelled representation of the testing process.FindingsThis analysis finds the mode of the as-built distribution of air permeability as 4.38 ± 0.01 m3/m2h. It predicts that 39 per cent of dwellings aiming for one of the five most common design targets have sealing interventions at the point of pressure testing to meet their target. The as-built distribution of the ATTMA data is compared to airtightness test data obtained from just before compulsory testing was introduced, showing an improvement in the modal air permeability of 3.6 m3/m2h since testing became mandatory.Originality/valueThis paper has investigated the available data beyond simply what is reported, to estimate what the real levels of airtightness in the UK new build stock may be.

The relationship between airtightness and ventilation in new UK dwellings

The UK’s Air Tightness Testing and Measurement Association competent persons scheme collects pressure test data and metadata from the majority of new build dwellings in the UK. This article uses the dataset to investigate the importance of the ventilation strategy in airtightness design and construction. Design and measured airtightness were tested for association with declared ventilation strategy. It was found that ventilation strategy makes a statistically significant difference to airtightness; however, this difference is too small to be practically relevant. Properties with mechanical ventilation and heat recovery (MVHR) were shown to have a mean designed air permeability only 0.46 m3/m2h lower than naturally ventilated dwellings. Seventy-three per cent of homes with MVHR have design airtightness greater than or equal to 5 m3/m2h and 17% of naturally ventilated dwellings have design airtightness less than 5 m3/m2h. We discuss how current design is not maximising the CO2, cost and air quality benefit of each ventilation strategy. A new approach to regulatory compliance is proposed, which explicitly links the designed airtightness and chosen ventilation system. It is suggested that compliance could then be achieved using a set of airtightness ranges linked to appropriate ventilation strategies. This could be expected to result in reduced energy consumption and carbon emissions for new build homes compared to the current approach and would also potentially lead to better outcomes for occupants in terms of indoor air quality. Practical application: Analysis of a large database of the airtightness of new UK dwellings found that ventilation strategy makes very little difference to airtightness design. For dwellings with MVHR, the results suggest that infiltration levels are too high to maximise the energy savings; for naturally ventilated homes, there may be air quality issues. Coupling airtightness design and ventilation strategy can reduce a dwelling’s energy demand and can support achieving the required energy performance rating.

‘Hitting the target and missing the point’: Analysis of air permeability data for new UK dwellings and what it reveals about the testing procedure

Airtightness testing is widely undertaken to assess the as-built performance of dwellings, in support of achieving energy and ventilation strategies. Mandatory schemes operate in some countries, such as the UK, to ensure that dwellings are built in accordance with their design air permeability. However, testing is only useful if the results give a true picture of the airtightness of the building. Previous literature has investigated factors which could influence airtightness test results but has not questioned data quality, despite the pressure on builders to achieve design targets. This paper presents air permeability results from the largest UK dataset, comprising 144,024 dwellings tested under the Air Tightness Testing and Measurement Association (ATTMA) scheme. The data show an unexpected distribution of test results with narrow peaks just within test targets. Such results were not expected theoretically but do reflect findings in other fields where performance-based targets are in place. Such a close match between design and tested airtightness may be achieved by remedial works taking place during the test rather than afterwards. Recommendations are made with respect to quality assurance systems, design guidance and on-site sealing practices to increase the likelihood of long-term airtight buildings being constructed first time.

Design of Airtight Test for Aircraft Air-conditioning System

This paper put forward a new design scheme of air tightness testing equipment mainly for the air conditioning system of a certain aircraft, with the introduction of pressure transmitter, temperature transmitter and single chip microcomputer. the system in the original basis, aimed at some problems in the optimization, the manipulation of the measuring equipment to improve automation, increasing the automatic data acquisition, recording and judgment, adopting touch screen technology, and improves the human-computer interaction.

Испытание составных вентиляционных блоков на герметичность

Испытание составных вентиляционных блоков на герметичность

Wood Based Building Envelope Regarding Air Tightness

The paper deals with laboratory air tightness testing of wood based construction materials with the focus on the proportion of air infiltration through the building envelope in the air exchange of the building. Results of the specific materials testing – cross laminated timber (CLT), OSB and other structural materials are analysed in the paper. Moreover, the effect of production technology, material, its thickness and surface treatment are studied. Results of laboratory testing provide valuable data for detailed computer modelling of air exchange through the infiltration, especially in vapour diffusion-open elements of building envelope.

Development and Testing of Environmentally Friendly Envelope for Energy Efficient Buildings in the Czech Republic

In many countries of Central Europe is a stock of existing buildings from 1950's to 1980's featuring original panel curtain walls. These envelope structures are now at the end of their service life and thus replacement solution is needed.There are various replacement alternatives such as aluminium, steel or steel-plastic panels, but these structures have typically high amounts of embodied energy and carbon footprint. Within national research project Intelligent Buildings, Czech Technical University in Prague has developed a timber-based curtain wall system called Envilop. The paper presents its development and laboratory testing. Properties of Envilop were proven by modeling, calculations and experiments inline with actual standards on curtain walls systems and in addition life cycle assessment (LCA) was performed. Heat and moisture simulations proved that does not suffer from thermal bridges and has U-values at levels suitable for passive housing; air tightness testing proved high quality of design. LCA calculations compared the system to aluminum-based alternative and show significant potential to savings in embodied energy and carbon footprint by using Envilop.

The Changing Requirements of Airtightness in the US for Commercial Buildings - The Airtightness of Mid and High-Rise Non-Residential Buildings

Concern over the airtightness of commercial buildings in North America goes back to the mid nineteen sixties, and with increasing concern in the mid-seventies, primarily due to the energy crisis, but also due to building performance, comfort and durability issues. The Model Canadian National Building Code was the first to adopt airtightness requirements for air barriers in 1985 and quantify it in 1995. In 2001 Massachusetts became the first state in the US to adopt a quantified airtightness requirement for air barrier materials and criteria for their design and construction in commercial and high-rise residential buildings. Many Standards and guides followed suit with airtightness requirements, including ASHRAE 90.1 2010 and IECC 2012, making airtightness mandatory in all commercial buildings built to those Standards and Codes. The US Army Corps of Engineers instituted airtightness testing requirements for all its new and renovated buildings in 2009. It requires that a whole building air leakage test be performed at completion of construction to verify performance of the constructed air barrier system. The Air Leakage Test Protocol for Building Envelopes was developed by the USACE Engineer Research and Development Center (ERDC) together with the Air Barrier Association of America (ABAA). In the meantime, ASHRAE decided that there was a lack of scientifically gathered and reported data on modern mid- and high-rise non-residential buildings built since the year 2000. It instituted a research study, 1478 RP, to measure and report air leakage rates for existing mid- and high-rise buildings, to develop a protocol for testing large buildings and to analyze the results with respect to design and construction parameters.

Air Tightness Testing for Biosafety Level 3

All bio-containment guidelines and inspection documents set requirements for airtight containment boundaries around biohazards. Current international containment guidelines only scratch the surface for biosafety level 3 (BSL-3) and the available tests proposed are not entirely suitable for such facilities. Some steps in the right direction have been taken, notably as outlined in the standards put forth in the Australia-New Zealand model for their Physical Containment 3 designation.