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building science Archives - Morrison Hershfield

CSC Annual Conference: 2 Presentations

By Ami Case | | No Comments

We’re proud to announce that we’ll be presenting two sessions at this year’s Construction Specifications Canada (CSC) Annual Conference.

Christian Cianfrone, Building Energy Specialist, will be presenting Emerging Solutions, Products and Methods for Getting to Net Zero. This session will take place on Thursday, May 24 at 10:30 am.

Presentation Overview:

Significant strides have been made in Canada with regards to the development of netzero/ zero carbon building policies and programs, ranging from provincial legislation to municipal policy to voluntary green building programs. These policies and programs have been primarily influenced using data-driven guidance, which has led to an in-depth understanding of the building strategies and technologies that are required to meet these high performance targets, as well as limitations and challenges. These solutions and limitations will be discussed in detail, through the lens of products, systems and methods that may influence how contract documents are developed.

 

Stevan Vinci, Senior Sustainability / Building Science Specialist, will be presenting Building Envelope Commissioning and LEEDv4. This session will take place on Thursday, May 24 at 1:45 pm.

Presentation Overview:

The Commissioning process has historically attached itself to the active systems, leaving the primarily passive envelope systems undefined and unchecked. However, due to the significant changes in City and State Energy Codes across the US which are addressing envelope design requirements to meet air leakage control and thermal performance targets, a new light has been directed at the importance of commissioning the passive systems. The code changes are requiring designers and contractors to deliver higher performance of their buildings, especially from the building envelope. Building Envelope Commissioning (BECx) is a topic that will enable designers to be prepared for not only the new changes being implemented in LEED v4, but also to stay current on how certain building envelope assemblies perform related to energy performance while ensuring long term durability. Commissioning the building envelope is progressively recognized as an important element in achieving optimal building performance.

Portland BEC: A Case History of ETFE on Recent Projects

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Stéphane Hoffman, Vice President / Senior Building Science Specialist, will be presenting A Case History of ETFE on Recent Projects for the Portland Building Enclosure Council (BEC) April Meeting.

Presentation Overview:

ETFE, the fluorocarbon-based polymer ethylene tetrafluoroethylene, is quickly gaining popularity in North America and being used on some of the continent’s most prominent projects. ETFE was developed for architectural purposes in the 1970s, and since that time, mainstream use of ETFE in construction projects has been largely limited to Europe. The material has many attractive attributes that provide not only a new aesthetic quality, but also potential cost savings. Weighing in at roughly one percent of the weight of glass, significant reductions in structural costs are made possible by employing ETFE. Despite these great potential benefits, the material is not an equal substitution to glass or other roofing systems in many respects. Through review of material characteristics, performance modeling, and multiple case studies of current ETFE installations, the authors will discuss lessons learned, limitations, as well as the benefits of the material from the perspective of building science implications.

Facade Tectonics World Congress 2018: 4 Papers, 3 Presentations

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We’re excited to announce that our Building Science Team has had 4 papers accepted and will be presenting 3 sessions at this year’s Facade Tectonics World Congress in Los Angeles.

Presentations include:

Quantifying the Benefit of Venting Glazed Spandrels to Reduce Glass Breakage and Control Moisture
Presented by Julien Schwartz, Building Energy Consultant, and co-authored with Stéphane Hoffman, Patrick Roppel and Neil Norris

Presentation Overview:

While venting glazed spandrels is cited to be a benefit to control heat buildup, several instances of spontaneous glass breakage in spandrel insulated glazing units, attributed to thermal stress, have been reported in vented spandrel cavities used with an opacifier on the inside glass surface. The implication is that if venting is not an effective solution to reduce thermal stress and the associated need for higher strength glass, then it is desirable not to vent to avoid dirt buildup on the inside glass surface as it cannot be cleaned. The benefit of venting or weep holes must also be evaluated in terms of condensation risk and damage.

The objective of this paper is to address questions related to the real need to vent spandrel sections to control heat buildup. This paper covers a field study that includes monitoring spandrel sections with a combination of single- and double-glazing, three different venting scenarios, and both clear- and opacified-glass scenarios. The data collected will be used to calibrate 3-D thermal and CFD simulations. The computer simulations will allow for cross-validation of the field monitoring data and broaden the relevance of the findings through the investigation of other conditions including different spandrel designs, venting scenarios, and climates.

The field monitoring suggests that venting the spandrel cavity has little to no impact on reducing thermal stress in clear-glass double-glazed spandrel sections, and a limited impact in clear-glass single-glazed spandrel sections. With the higher solar absorption associated with an opacifier coating, venting shows even less impact on reducing thermal stress, with some data suggesting an adverse effect. Also, in the temperate climate of this field study, the condensation risk was found to be very low regardless of the venting configuration. Based on these preliminary results, there is reason to question the need to vent double-glazed spandrel sections. The 3-D thermal and CFD model is currently being calibrated and findings will be presented in a subsequent paper. Preliminary simulations results show good agreement with the field monitoring data.

 

Vintage Vinyl: Lock-strip Gasket Replacement and Remediation
Presented by Mike Plewacki, Senior Building Science Consultant

Presentation Overview:

Mid-century through 1980’s buildings with lock-strip or “zipper-gasket” glazing systems are an ever present part of the urban landscape in many cities across North America. Although these systems are considered outdated by many and seldom used in new construction, the systems have performance attributes that should merit respect.

For many in the façade community, lock-strip gasket facades are often dismissed as a system to be removed and replaced with modern aluminum curtain wall. While this may be practical in certain situations, it is far from the only option available and not always the right option for the owner’s budget or maintaining the original architecture of a building.

Lock-strip facades continue to endure but age has taken its toll on the functionality of what was once a revolutionary glazing system. By maintaining the lock-strip gasket façade and upgrading glazing when possible, building performance can be restored or even increased as retrofit technology improves.

Remedial options are available for a lock-strip gasket façades that focus on preserving and maintaining the primary elements and appearance of the system from simple remediation efforts such as the installation of exterior “wet-seals” to limit air and water infiltration, to complete replacement and reglazing.

Improved curtain wall performance (reduced air infiltration, lowered solar heat gain and improved acoustical performance) are achieved by introducing modern insulating glass with a low-e coating and emerging technologies, such as vacuum insulating glass (VIG), present possibilities for replacement of an original monolithic glazed system for increased energy performance. Reglazing also provides the opportunity to increase spandrel insulation, or change the aesthetic of the façade by introducing (or removing) existing spandrel panels.

While the benefits of the above are appealing, lock-strip gasket replacement projects are not immune to challenges. As with most remediation projects there are technical considerations to address.

 

Fully Tempered Glass in Spandrel Applications: Assessing the Residual Strength after Inner Light has Shattered
Presented by Stéphane Hoffman, Vice President / Senior Building Science Specialist

Presentation Overview:

Recent years have seen an increase use of insulated glazing units (IGUs) in spandrel applications to visually blend the appearance between the vision and spandrel glass. There has been instances of glass breakage for this type of design attributed to thermal stress. Recent study indicate that IGUs in spandrel application see higher thermal stress than with traditional single glazed spandrel and that venting the spandrel cavity does little to minimize this increase in thermal stress. Recent research supports the theory that the increased in thermal stress is leading to breakage of the inner light due to lowered strength in heat strengthened ceramic opacified glass.

In response to this phenomenon considerations are being given to using fully tempered glass for the inner light when using a ceramic frit opacifier. The later raises interesting questions regarding the performance of the glazing in the event of a failure of the inner light. While fully tempered lights have a long history of use in IGUs for safety reasons, it is not uncommon to have the occasional incidence of spontaneous breakage. However, in vision glazing units these failures are readily apparent and promptly addressed. In spandrel applications, the failure of a fully tempered inner light may go unnoticed. This raises questions as to how much residual strength a unit with a shattered inner light would have to resist wind loads. The result of testing of structurally glazed IGUs with a fully tempered inner light that has been shattered demonstrated the residual strength was sufficient to resist an initial application design wind loads. The results provide guidance to designers considering the use of fully tempered glass in spandrel applications.

 

PAPER – Silicone Spandrel Glass Opacifiers: Mitigating Glass Breakage Risk from Thermal and Other Stresses
Co-authored by Stéphane Hoffman, Vice President / Senior Building Science Specialist, and George Torok, Senior Building Science Specialist – this session will be presented by a representative outside of Morrison Hershfield

Presentation Overview:

Curtain wall design commonly uses insulating glass units for vision and spandrel glazing to provide better visual harmonization of building façade glass. Risks with this design approach include higher thermal stresses, especially when low-emissivity coatings are used on insulating glass units in spandrel areas. Ceramic enamel frit – commonly used to opacify spandrel glass – is known to induce a bending strength reduction of up to 50%. The ability of ceramic enamel frit coated glass to resist thermal stress is similarly reduced. Multiple incidences of thermal stress related fracture have occurred with heat-strengthened, ceramic enamel frit opacified spandrel glass. An increased chance of spontaneous breakage, by nickel sulfide inclusions, may occur if ceramic enamel frit opacified spandrel glass is fully-tempered to withstand the thermal stresses that it is exposed to.
Silicone spandrel glass coatings have been examined as a solution to prevent the strength reduction in heat-treated glass when ceramic enamel frit is applied as an opacifier. Four-point bending tests were used to investigate the flexural strength of coated heat-strengthened and fully-tempered glass. Ball drop testing was used to investigate the impact resistance of coated fully-tempered glass.

Webinar: CaGBC Emerging Green Professional Mentor

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Join the Canada Green Building Council’s (CaGBC) free webinar and learn the secrets of launching a successful green building career. Hear more about how you can get started in making a difference in the sustainability field and gain valuable, real-life insights from a fellow young professional.

This session will take place from 1:00pm – 1:45pm EST on Tuesday, February 20.

This webinar features Alex Blue, Principal and Building Energy Specialist. Alex has been involved with commercial, multi-unit residential and institutional projects across Canada and the United States. She co-leads Morrison Hershfield’s LEED energy review team and has taught sustainability courses at the University of British Columbia. She is involved in energy modelling and green building communities and is one of the founding board members of the IBPSA-Canada BC Chapter. Alex is also one of the instructors for CaGBC’s LEED Strategic Practices Program.

AIA Seattle Sustainable Design Series: Passive House and Commercial Construction

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AIA Seattle’s Corporate Allied Partners (CAPs) enliven the AIA Seattle community and value involvement with AIA Members.

This year, Medgar Marceau, Building Science Engineer, will present Passive House and Commercial Construction at AIA Seattle’s Sustainable Design Series. The series is a full-day workshop with 7 sustainable-design presentations.

Medgar’s presentation will begin at 10:40 a.m. and is eligible for one AIA LU|HSW credit.

Presentation Overview:

The accelerating growth of Passive House across the US and Canada is leading a change in the building envelope industry across the Pacific Northwest. With Vancouver’s new mandate to meet the Passive House standard for all city-owned commercial buildings, and Seattle’s progressively stricter energy codes, it’s only natural that our industry will have new challenges to meet on the pathway of sustainability. There is a large knowledge base of how to build durable residential buildings that meet the Passive House standard. However there are few examples of commercial buildings meeting Passive House. This presentation will help bridge the knowledge gap between residential and commercial construction. Basic principles of Passive House are high levels of insulation, no thermal bridging, an airtight building, very high-performance windows and doors, heat and moisture recovery ventilation, and optimizing solar heat gains. All of this while ensuring occupant comfort and durability are paramount. Achieving these objectives in Passive Commercial will require the same.

Learning Objectives:

  • Understand the challenges in translating Passive House to Passive Commercial
  • Examine solutions for: A) minimizing thermal bridging in commercial construction; B) providing an air-tight interior vapor retarder
  • Discuss thermally efficient at-grade and below-grade transitions
  • Utilize 2-D and 3-D simulation tools to evaluate hygrothermal performance

Greenbuild 2017: Energy in LEED today and tomorrow

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Christian Cianfrone, Building Energy Specialist, will present Energy in LEED Today and Tomorrow on Thursday, November 9 at 9 a.m.

Presentation Overview:

Discussions about the water-energy nexus have reignited conversations about energy impacts and consumption. Presenters will use real-world examples to show how unique building and space types have successfully implemented and documented their energy impacts and performance. During this session, we will delve into how LEED addresses energy today through LEED v4 and through pilot credits and also take a look towards how today’s trending topics, like the water-energy nexus impact LEED’s future goals.

Learning Objectives:

  • Provide an overview of how LEED v4 addresses energy in all rating systems – LEED BD+C, ID+C, O+M, ND and Homes – and related credits.
  • Review different strategies for achieving the LEED v4 energy-related credit across all LEED rating systems.
  • Review real world examples of how LEED energy-related credits and strategies have been applied.
  • Discuss the future of energy issues, solutions and strategies and the impact they have on the development of future LEED credits and pilot credits.

CCBST 2017: 8 Presentations and 9 Papers

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Morrison Hershfield is proud to announce that we are having 9 papers featured and 8 presentations at this year’s Canadian Conference on Building Science and Technology (CCBST)!

Here’s a quick overview of our sessions taking place over the three-day conference:

Lessons Learned from Laboratory Testing Failures of Glazing Systems

Andy Lang, AScT – Building Science Specialist

Curtain walls and window walls are typically specified to meet a variety of different performance and testing criteria, some of which can be quite stringent.  Such requirements are defined in specific codes and industry standards, including, but not limited to new 2015 requirements of the National Building Code of Canada, the International Building Code, AAMA 501 – Methods of Test for Exterior Walls, and ASTM E2099 – Standard Practice for the Specification and Evaluation of Pre-Construction Laboratory Mockups of Exterior Wall Systems.

 

Critical Review of a Whole Building Air Leakage Testing Requirement

Lee Durston – Senior Building Science Consultant

Over the past decades, energy codes have brought a number of changes with respect to improving the performance of the building envelope both in design and construction.  With respect to the building enclosure, the most debatable is the increasing importance placed on air-leakage and how this often unknown value affects many of the energy efficiency metrics that define the performance of the building.  Throughout the world, there are multiple codes and standards requiring varying levels of air tightness as well as varying performance levels and methods of verification. As the requirements and performance implications become better understood, common design and construction practices will experience shifts toward improved performance, as was experienced in the early years of the USACE requirements on which the private sector codes are based.  However, variations between these standards and performance testing requirements have also brought about questions as to whether the testing is warranted and truly beneficial.  Through a review of multiple case studies of past and current enclosure consulting and whole building air leakage testing, including high-rise, multi-family, and other commercial new and renovation construction, this presentation will provide a critical review of these codes and standards for validity, impact, and relevance.

 

A Case History Review of ETFE on Today’s Current Projects

Lee Durston – Senior Building Science Consutlant

ETFE, the fluorocarbon-based polymer ethylene tetrafluoroethylene, is quickly gaining popularity in North America with it’s use on some of the continent’s most prominent projects.  ETFE was developed for architectural purposes in the 1970s, and since that time, mainstream use of ETFE in construction projects has been largely limited to Europe. The material has many attractive attributes that provide not only a new aesthetic quality, but also potential cost savings.  Weighing in at roughly one percent of the weight of glass, significant reductions in structural costs are made possible by employing ETFE. Despite these great potential benefits, the material is not an equal substitution to glass or other roofing systems in many respects.  Through review of material characteristics, performance modeling, and multiple case studies of current ETFE installations, the authors will discuss lessons learned, limitations, as well as the benefits of the material from the perspective of building science implications.

 

A Compartmentalization & Ventilation System Retrofit Strategy for High-rise Residential Buildings in Cold Climates

Matt Carlsson – Building Science Consultant, et al

This research proposes an alternative rehabilitation strategy for aging high-rise multi-unit residential buildings (MURBs) involving suite compartmentalization and decentralizing the ventilation system. Energy efficiency retrofits of MURBs today tend to focus on increasing the thermal performance and air-tightness of the enclosure, which neglects the inherent inefficiency and ineffectiveness of pressurized corridor ventilation systems, and often amplifies deficiencies. An alternative approach is to isolate the suites from the corridors, and install balanced heat recovery ventilators in each. Ventilation can then be maintained at design rates, and regulated according to need. This proposed retrofit was investigated for an existing high-rise MURB in Vancouver. Computer simulation using EnergyPlus™ (v.8.4.0) was used to examine the impact of the proposed retrofit on the case study building. Results show annual heating energy decreased by 51% and overall GHG emissions decreased by 29%. The main benefit of the proposed retrofit, however, is improved zone air distribution of the mechanical ventilation system. Because building enclosure air-tightness improvements can negatively impact air distribution in buildings with pressurized corridor ventilation systems, the proposed retrofit should be applied in combination with, or before, an enclosure retrofit. Thermal resilience should also improve, with longer passive surviveability durations from a reduction in uncontrolled air leakage induced by stack effect.

 

Insulated Metal Panels – Design and Construction Challenges:

Harold Louwerse, BTech, RRO – Building Science Consultant

Exterior insulated assemblies are growing in popularity due to changing code requirements with regards to thermal resistance for opaque wall assemblies. Simply installing batt insulation inside the stud cavity is not sufficient any more. Moving forward, the now obvious thermal benefits of continuous insulation combined with improvements in technology and manufacturing over the last 10-15 years have propelled exterior insulation assemblies to the forefront of envelope solutions.  Insulated Metal Panels (IMP’s) are one of the exterior insulation options that Owners, Architects and Engineers now consider an attractive, cost effective, all-in-one building envelope solution.  IMP’s are being used on a growing number of projects as the air, vapour, moisture barrier, cladding and insulation, or a combination thereof.  Designing and constructing wall assemblies with IMP’s can be a simple and effective method of enclosing a building, but it may pose challenges, especially on complex geometric buildings.  Challenges could include integrating the IMP’s with other building envelope assemblies or achieving the desired airtight and thermally efficient building envelope from an installation perspective.

Design Limits for Framed Wall Assemblies Dependent on Material Choices for Sheathing Membranes and Exterior Insulation

Ivan Lee – Building Science Consultant, Mark Lawton – Senior Building Science Specialist & Patrick Roppel – Building Science Specialist

There are many opinions in industry with regard to appropriate material choices for sheathing membranes and exterior insulation of framed wall assemblies.  Opinions vary on what is sensible for the vapour permeance of materials outboard of the framing so that not only will wetting and drying will be in harmony, but other interests such as costs, wall thickness, and energy efficiency targets can be met.

 

Fenestration Systems – It Is All About the Plumbing!

Peter Adams, P.Eng. – Senior Building Science Specialist & Yvon Chiasson, P.Eng. – Building Science Specialist

A few years ago the Toronto office of our engineering firm experienced what we termed “the year of the crappy curtain wall”. In actuality it was more like eighteen months, and during that period we investigated persistent water penetration in several low- to mid-rise commercial office buildings ranging in age from 5 to 20 years old. The failures discovered were not unique to curtain wall systems and were entirely avoidable if those responsible had even a basic understanding of how these systems are supposed to function. For several of the buildings we investigated, the failures were in conventional, fully captured curtain wall systems that were not installed correctly from the get go. There are many excellent, qualified curtain wall installers out there, but apparently they were off benefiting other jobs when these buildings were constructed.

 

Quantifying the Benefit of Venting Glazed Spandrels to Reduce Glass Breakage and Control Moisture

Julien Schwartz – Building Science Consultant & Patrick Roppel – Building Science Specialist
Stephane Hoffman – VP / Senior Building Science Specialist & Neil Norris – Building Science Engineer

While venting glazed spandrels is cited to be a benefit to control heat buildup, several instances of spontaneous glass breakage in spandrel insulated glazing units, attributed to thermal stress, have been reported in vented spandrel cavities used with an opacifier on the inside glass surface. The implication is that if venting is not an effective solution to reduce thermal stress and the associated need for higher strength glass, then it is desirable not to vent to avoid dirt buildup on the inside glass surface as it cannot be cleaned. The benefit of venting or weep holes must also be evaluated in terms of condensation risk and damage.

Net Positive Symposium: Thermal Bridges in Passive House Design

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Christian Cianfrone, Building Energy Specialist, will present Thermal Bridges in Passive House Design on day 2 of the symposium, October 31 at 1 p.m.

Session Overview:

As Passive House becomes increasingly popular in commercial, institutional, and high rise multi-unit residential construction, our understanding of thermal bridging needs to consider an expanding range of materials, assemblies and construction methods. Luckily, quantifying the impact of and mitigating thermal bridges has been the subject of research for the last several years, yielding a large amount of data that industry can benefit from. This presentation will introduce participants to an exciting project that is currently in development – an online Thermal Bridging Performance Database. Participants will get a sneak peek into the resource, including how the data can be leveraged to make better decisions on projects and ultimately reduce energy use on buildings.

FenWest 2017: Aluminum Framed Glazing Systems

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Andy Lang, Building Science Specialist, will be presenting Performance of Aluminum Framed Glazing Systems Subject to Seismic Displacements at 2:15 p.m. on October 24.

Session Overview:

This presentation describes the design and installation of aluminum framed glazing systems to accommodate lateral displacements when subject to seismic drift of the building structure. The presentation includes stick built and unitized curtain walls as well as window walls. Examples will be presented of how aluminum framed glazing systems performed when subject to lateral displacement during laboratory mock-up testing.

Engineers & Geoscientists of BC Annual Conference: The BC Energy Step Code

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Christian Cianfrone, Building Energy Specialist, will be presenting a session titled The BC Energy Step Code: What Engineers and Geoscientists Need to Know Today at 3:45 p.m. on October 20.

Session Overview:

B.C.’s Climate Leadership Plan set a goal to ensure all new buildings will be net zero within 15 years and introduced the BC Energy Step Code as the policy path to get there. The panel discusses the BC Energy Step Code and brings engineers up to speed on the nuts and bolts, including barriers to adoption that have been identified to date and options to mitigate them. Learn what you need to know about this emerging standard.