Critical Analysis of in situ Performance of Glass Fiber Core VIPs in Extreme Cold Climate

Glass fiber core vacuum insulation panels (VIPs) are becoming an increasingly attractive option for building envelope construction due to lower cost and availability around the world. Although fumed silica core VIPs have shown superior long-term performance under accelerated aging tests compared to glass fiber core VIPS, these laboratory test results have yet to be verified with long-term field performance data. In 2011, glass fiber core VIPs were installed in a commercial building retrofit project in Yukon, Canada (one of Canada's most northern territories), and have been continuously monitored since. This paper summarizes the thermal performance of the glass fiber core VIPs over the period of 2011–2018 in an extreme cold climate. Findings from this study provided data to validate glass fiber core VIP accelerated aging test results and the aging rate of VIPs in a cold and dry climate was determined. These results will help developing a better understanding of the long-term performance of glass fiber core VIPs in a real-world context

Annex 65, Long-Term Performance of Super-Insulating-Materials in Building Components and Systems. Report of Subtask III: Practical Applications – Retrofitting at the Building Scale – Field scale

More than 80% of the energy consumption will be influenced by the existing building stock. Accordingly, building renovation has a high priority in many countries. Furthermore, several studies have shown that the most efficient way to curb the energy consumption in the building sector (new & existing) remain the reduction of the heat loss by improving the insulation of the building envelope (roof, floor, wall & windows). All since the first oil crisis in 1973-1974, the national building regulations require improvement of the thermal performance of the building envelope to significantly reduce the energy use for space heating. Following the regulations, the energy efficiency of new buildings has improved. In Europe, targeting to an average U-value close to 0.2 W/m2\ub7K is optimal. Using traditional insulation materials this means an insulation thickness of about 20 cm. Thus, the thickness of internal and/or external insulation layers becomes a major issue of concern for retrofitting projects and even for new building projects in cities. Therefore, there is a growing interest in the so-called super-insulating materials (SIM). The scope of the present work covers two different types of SIMs:• Advanced Porous Materials (APM), where the gaseous heat transfer is hindered significantly by the fine structure in the sub-micrometre range, and• Vacuum Insulation Panels (VIP), where the contribution of gaseous conductivity to the total heat transfer is suppressed by evacuation.For Advanced Porous Materials (APM) one might distinguish between• porous silica e.g. based on fumed silica, and• aerogels.For Vacuum Insulation Panels (VIP) one might distinguish between:• different core materials: fumed silica, glass fibre, PU, EPS, others;• different envelopes: metalized film, aluminium laminate, stainless steel, glass, or combinations;• with or without a getter and/or a desiccant.The objective of this Annex 65 Subtask 3 report is to define the application areas of SIM and to describe the conditions of the intended use of the products. Indeed, it’s clear that the requested performance of the SIM will strongly depend on the temperature, humidity and load conditions. For building applications, storage, handling and implementation requirements are also described. Common and specific numerical calculations will be performed at the building scale to assess the impact of SIM on the performance of the building envelope.SIM was used in almost all building components with different environmental condition (boundary condition) and in different climate zone. The moisture and temperature conditions in building components can cause moisture/temperature induced stresses and the stresses can cause damage in sensitive super insulation material e.g. VIPs. Thus, to convince the conservative market of construction, it needs, in addition to laboratory measurements, real condition/environmental measurements of commercially realized objects (new buildings as well as refurbishments) under several years of operation.The long-term performance of super insulation materials has to be determined based on case studies in field and laboratory. Full scale experiments provide knowledge of practical and technical difficulties as well as data for service life estimation. For certain conclusions to be drawn from the case studies, monitoring is essential. Unfortunately, monitoring is only performed in few case studies. In this report these experiences are gathered and evaluated from a long-term performance perspective.APMs have been commercially successful in the building industry in niche applications typically with space restrictions since the early 2000s. Therefore, over the last years, a number of state-of-the-art reviews have focused on applications of advanced porous materials, such as aerogels, used as thermal insulation in buildings. VIPs, on the other hand, have also been used in other applications than buildings, such as refrigerators and transport boxes. The different applications areas have been identified by numerous researchers. However, in most studies of VIPs available in the literature, it was only the thermal performance of the assembly that was investigated. However, also the moisture performance is important to consider since changes to existing structures will influence the risk for moisture damages.In the Annex, the gathered case studies cover a wider range of SIM i.e. aerogel blankets, AB, (7 case studies), silica-based boards, SB, (3 case studies) and VIP (22 case studies). The aim was to gather information from projects where SIMs were used in different assemblies. Some of the projects have been monitored, i.e. sensors were installed to monitor the temperature, relative humidity or heat flux through the assemblies, while only three have been followed up, i.e. where a third party have analysed the results of the monitoring. The case studies are presented and specific and general conclusions from each application are made.The case studies showed that aerogel blankets are possible to install in up to five layers (50 mm) without too much difficulty. The evaluations showed that the performance of the aerogel blankets was maintained over the evaluation period. For VIPs, it is difficult to evaluate the performance when installed in the wall. In one of the case studies in the report, the external air space made it impossible to identify the different panels by thermography. Only indirect methods, like evaluation of the measured temperatures in the wall, can be used to follow the long-term performance of the panels. In another case study, hybrid insulated district heating pipes were installed at two locations in a district heating system with temperatures up to 90\ub0C. Measurements during the period 2012 to 2015 showed no sign of deterioration of the VIPs and the temperature profile over the pipes was constant. An existing masonry wall was insulated with VIP-foam sandwich (XPS-VIP-XPS). It showed satisfactory and promising performance for a period of six years (2011-present). The analysis of the data obtained from continuous temperature monitoring across each insulation layer indicated the aging of VIP remains insignificant.In the framework of IEA EBC Annex 65 a common simulation-based procedure was introduced with the scope to identify potential critical hygrothermal working conditions of the SIM, which were identified as main drivers of the ageing effect. The study highlights that some physical phenomena (such as thermal bridging effects, the influence of temperature on the thermal conductivity and the decay of performance over time depending on the severity of the boundaryconditions) should be carefully evaluated during the design phase in order to prevent the mismatch between expected/predicted and the actual thermal performance.As general guidelines to mitigate the severity of the operating conditions of VIP, a list of recommendation are in the following summarised:• For the external wall insulation with VIP in solar exposed fa\ue7ade, the adoption of ventilated air layer could dramatically reduce the severity of the VIP operating conditions. Alternatively, light finishing colour are warmly encouraged to mitigate the surface temperature.• The protection of VIP with thin traditional insulation layer is always encouraged.• The application of VIP behind heater determines high value of surface temperature field which could potentially lead to a fast degradation of the panel. A possible solution to mitigate the severity of the boundary conditions could be the coupling of VIP with a radiant barrier, or the protection of VIP with thin insulation layer when it is possible.• In roof application, light colour (cool roof), performant water proof membrane, ventilated airspace and gravel covering layer (flat roof) represent effective solutions to mitigate the severe exposure.• In presence of wall subjected to high driving rain, it is preferable to adopt ventilated fa\ue7ade working as rain-screen to prevent the water absorption.Furthermore, to provide designers, engineers, contractors and builders with guidelines for the applications of vacuum insulation panels (VIPs) and Advanced Porous Materials (APMs) examples are given of methods that may be used to verify the quality and thermal performance of SIMs after installation. A comprehensive account of transport, handling, installation and quality check precures are presented. The main purpose of the descriptions is to promote safe transport, handling and installation. In the case of VIPs the primary issue is that of protecting the panels whereas the main concern for APMs is the safety in handling of the material.During the work of the Annex several questions regarding the long-term performance of SIMs on the building scale have been identified and discussed. Four main challenges were identified:• Knowledge and awareness among designers concerning using SIM• Conservative construction market• Cost versus performance• Long-term performance of SIMsFinally, SIMs for building applications have been developed in the recent decades. Theoretical considerations and first practical tests showed that VIP, especially those with fumed silica core, are expected to fulfil the requirements on durability in building applications for more than 25 years. Both VIPs and APMs have been successfully installed over the past 15 years in buildings. However, real experience from practical applications exceeding 15 years is still lacking, especially when considering third-party monitoring and follow up of demonstrations

Role of Empathy in Engineering Education and Practice in North America

Does engineering design education in North America prepare students to address the major issues of our time? In today’s political and social climate, engineers are part of multi-disciplinary teams tasked with finding solutions to complex issues like poverty, climate change, the housing affordability crisis, resource depletion, and water shortages. By definition, these problems are “wicked”. If engineers are to play a role in addressing issues that exist at the intersection of technology and society, they must have a deep understanding of both technical competencies and of human factors. They must have the ability to empathize. In consideration of today’s social, political, and environmental challenges, it has never been more important to instill social competencies into engineering education and practice, particularly around engineering design. This paper analyzes the previous literature on empathy in engineering education in North America and synthesizes the data to present the conceptualization that engineers have of empathy in education and practice

Critical Review on Efficiency of Ground Heat Exchangers in Heat Pump Systems

Use of ground source heat pumps has increased significantly in recent years for space heating and cooling of residential houses and commercial buildings, in both heating (i.e., cold region) and cooling (i.e., warm region) dominated climates, due to its low carbon footprint. Ground source heat pumps exploit the passive energy storage capacity of the ground for heating and cooling of buildings. The main focus of this paper is to critically review how different construction and operation parameters (e.g., pipe configuration, pipe diameter, grout, heat injection rate, and volumetric flow rate) have an impact on the thermal efficiency of the vertical ground heat exchanger (VGHE) in a ground source heat pump (GSHP) system. The published literatures indicate that thermal performance of VGHEs increases with an increase of borehole diameter and/or pipe diameter. These literatures show that the borehole thermal resistance of VGHEs decreases within a range of 9% to 52% due to pipe configurations and grout materials. Furthermore, this paper also identifies the scope to increase the thermal efficiency of VGHE. The authors conclude that in order to enhance the heat transfer rate in VGHE, any attempt to increase the surface area of the pipe configuration would likely be an effective solution

The All-You-Can-Eat Economy: How Never-Ending Economic Growth Affects Our Happiness and Our Chances for a Sustainable Future

This paper explores the relationship between energy consumption, economic growth, and life satisfaction and makes the case that economic growth as usual is no longer a desirable or sustainable policy goal. Historically, economic and social development go along with energy sector transformation and total energy use. As a country develops, its use of energy increases, resource consumption increases, population booms, life expectancy rises, and overall socio-economic outcomes are improved. One might deduce then, that life satisfaction is also tightly correlated to economic development and energy consumption, but is this the case? To answer this question, current academic literature and data on the relationship between energy consumption, GDP, and quality of life were explored. The review showed a weak relationship between GDP and quality of life, a saturation relationship between energy use and social returns (social returns increase with increasing energy use to a point), and a strong relationship between GDP and energy use. There have been high hopes that improvements in energy-efficient technology will reduce global aggregate resource consumption, however, there is a growing body of research to suggest the opposite is likely to occur due to ”rebound effects”. The major environmental issues of our time have been seen predominantly as issues to be solved through advancements in technology; however, it is the argument of this paper that they cannot be addressed from a purely technological standpoint. Of course, improving energy efficiency is an important factor, but we must not forget the equally important subject of human behavior and our addiction to continual economic growth. We must first address the human desire to consume resources in the pursuit of happiness and socio-economic status, and shift towards a mentality of sufficiency. Future research must demonstrate concrete examples of sustainable development and consumption, advance the discourse on how the individual can be part of the solution, and empower the implementation of sustainable government policy

Effects of Extensive Green Roofs on Energy Performance of School Buildings in Four North American Climates

A comprehensive parametric analysis was conducted to evaluate the influence of the green roof design parameters on the thermal or energy performance of a secondary school building in four distinctively different climate zones in North America (i.e., Toronto, ON, Canada; Vancouver, BC, Canada; Las Vegas, NV, USA and Miami, FL, USA). Soil moisture content, soil thermal properties, leaf area index, plant height, leaf albedo, thermal insulation thickness and soil thickness were used as design variables. Optimal parameters of green roofs were found to be functionally related to meteorological conditions in each city. In terms of energy savings, the results showed that the light-weight substrate had better thermal performance for the uninsulated green roof. Additionally, the recommended soil thickness and leaf area index for all four cities were 15 cm and 5 respectively. The optimal plant height for the cooling dominated climates is 30 cm and for the heating dominated cities is 10 cm. The plant albedo had the least impact on the energy consumption while it was effective in mitigating the heat island effect. Finally, unlike the cooling load, which was largely influenced by the substrate and vegetation, the heating load was considerably affected by the thermal insulation instead of green roof design parameters

Implementing Green Roofs in the Private Realm for City-Wide Stormwater Management in Vancouver: Lessons Learned from Toronto and Portland

Green roofs are an innovative stormwater management technology that has numerous environmental benefits. Citywide implementation is critical to maximizing the benefits of green roofs, especially in terms of jurisdictional encouragement and advancing management programs. The City of Vancouver is interested in developing a rainwater management strategy that supports the widespread implementation of green roofs on private property. Performance control for a green roof on private property requires standards on local natural factors that affect performance; development considerations; supporting legal tools; maintenance and operation responsibilities; equity through the different types of private properties; and finally, cost. Research into the rainwater management strategies for the cities of Toronto and Portland for green roof implementation was conducted to provide insight into the best approaches for such an implementation in Vancouver. Portland and Toronto both have independent green roof standards in addition to separate rainwater management strategies. Portland focuses on a post-occupancy inspection program to monitor a green roof’s ongoing performance, while Toronto established the Green Roof Bylaw to encourage the implementation of green roofs. Incentive programs that educate and encourage private owners to take the initiative to construct and effectively operate green roofs are essential to the success of a private green roof program

In-Situ and Predicted Performance of a Certified Industrial Passive House Building under Future Climate Scenarios

The Wood Innovation Research Lab was designed as a low energy-use building to facilitate the construction and testing of engineered wood products by the faculty and staff of the Master of Engineering in Integrated Wood Design Program at the University of Northern British Columbia in Prince George, BC, Canada. Constructed using a 533 mm thick-wall and 659 mm flat roof assembly, it received certification as Canada’s first industrial facility built to the International Passive House standard. Temperature and humidity sensors were installed in the north and south exterior wall assemblies to measure long-term hygrothermal performance. Data collected between 2018–2020 shows no record of long-term moisture accumulation within the exterior assemblies. Data collected during this time period was used to validate hygrothermal performance models for the building created using the WUFI® Plus software. Long-term performance models created using future climate data for five cities across Canada under two global warming scenarios shows favorable results, with an increase in average annual temperatures resulting in lower average relative humidity values at the interior face of the exterior sheathing board in the exterior wall assemblies