November 30, 2015
By Pierre-Luc Baril, Eng., HFDP, LEED AP, and Nicolas Lemire, Eng., M.A.Sc., LEED AP
A tree must first take its strength from its roots, and a successful building must do the same. It is not possible to throw in some fancy ‘green’ devices once everything else has been decided to render a building ‘sustainable’ or simply add up various eco-measures and get a high-performing, energy-efficient facility. For a true sustainable result, it must come from the early stages of a project, with the roots guiding every decision. This simple analogy explains how John Abbott College approaches its new science and technology building project. It is also fitting because tree roots came into play for the school’s new design.
In the early 2000s, the college—located in Sainte-Anne-de-Bellevue, near the western tip of the Island of Montréal—was struggling to keep an edge with its sciences program because of the lack of proper space to teach an increasing number of students. Laboratories and classrooms more than 40 years old were too small and inadequate for contemporary demands and ways of teaching.
At this point, John Abbott College was in serious need of additional specialized, square footage. The school required a new building to teach physics, biology, and chemistry, as well as professional programs for nursing, paramedic, and the newly approved biopharmaceutical studies program. Further, the lack of adequate swing space rendered the renovation of the existing teaching space to be quite difficult.
To put things into perspective, John Abbott College is located on a historic campus with buildings dating back to the early 1900s. To fit a new construction inside this setting without having it look out of place was a serious challenge. Also, it was really important to reduce the impact of this new building in terms of environmental footprint.
Early on, the school decided to hire a complete set of professionals to discuss the possibility for this project and ensure the building would make a clear statement to the community about how important the environment is for future generations. The selection process included a first submission by potential architectural and engineering firms followed by specific interviews conducted by a multidisciplinary committee. At the end of the process, Saucier + Perrotte architectes was teamed up with Pageau Morel et associés inc. (mechanical/electrical/plumbing [ME]) and SDK et associés inc. (structural/civil). SNC-Lavalin served as project manager.
The new building
An integrative design process was established with the stakeholders and the team. This translated in several ‘charettes’ to discuss the ideas, obstacles, and opportunities related to the project. Goals were defined in terms of performance and sustainability for the new building. The potential construction site was quickly identified, but was limited by the existing building, a semicircle passage joining several buildings, and a Ginkgo tree located in the middle of the courtyard.
The tree was more than a century old, and the team felt it would be a powerful statement to incorporate its presence in the design of the new building. In other words, there needed to be a way to integrate the building design with the existing environment, and not the other way around.
The new Anne-Marie Edward Science and Health Technologies Building is a six-storey facility with a gross area of 11,280 m2 (121,416 sf) and a net interior area of 6200 m2 (66,736 sf). It contains classrooms, faculty offices, teaching laboratories with chemical fumehoods, social spaces, and a large atrium connecting every floor. This building is shaped at a 40-degree angle to fold around the Ginkgo. Also, the main staircase of the building, centrally located and fully glazed to the exterior, is designed to emulate the tree, with its branches extending upward. Fully glazed curtain wall and large windows were installed on a significant portion of the building to maximize natural light and views so the occupants could easily connect with the exterior.
This building was named after Anne-Marie Edward, a John Abbott graduate and engineering student who was one of the victims of the 1989 shooting at École Polytechnique in Montréal. The school felt the new science building, through engineering and applied sciences, showed how humans must contribute to environmental sustainability by using applied knowledge and technology.
Since this building had a lot of energy-intensive laboratories, it was paramount to include, in the early stages of design, advanced computerized energy calculation to evaluate different possibilities for overall energy consumption. The best-performing option considering the use of the building within the available budget included geothermal wells, thermal storage, radiant heating and cooling, and a decentralized fan coil network combined with efficient ventilation units.
The simulation based on the 1997 Canadian Model National Energy Code for Buildings (MNECB) predicted the building would use 39 per cent less energy than the baseline. Once the building was completed, real energy usage was monitored for the first year of operation and the results exceeded expectations by 10 per cent. In fact, actual energy use in the building is 45 per cent lower than the baseline case. Annual site energy intensity is currently 151 kWh/m2, whereas the baseline is 275 kWh/m2.
Key mechanical elements helped contribute to the building’s energy efficiency. For example, a hydronic network creates and distributes the energy all around the building; it is truly of vital importance to the building operation. This network is composed of 40 geothermal wells, each around 120 m (394 ft) deep. They are used to reactivate two 3000-L (792.5-gal) thermal storage tanks. These tanks—one cold and one hot—are connected to five two-stage heat pumps for a total capacity of more than 175 tonnes. They can simultaneously produce hot and cold water for the building needs.
Transferring energy from one place in the building to another without using any outside source of energy (i.e. neither heating nor cooling) is the best way to achieve energy savings. For example, during a winter day, the heat extracted from the interior zone can be used to compensate the loss of the perimeter. Geothermal heat pumps are generally three to four times more efficient than a traditional system in heating mode. This system responds to 50 to 70 per cent of the cooling and heating energy demands of the building. Two air-cooled rooftop chillers (each with 150 tonnes of capacity) and two electric boilers (288 kW each) cover the remaining needs during the peak season.
The envelope of the building is mainly heated with a radiant low temperature system using the concrete slab to distribute the necessary heating. The pipes were located in the lower portion of the slab so they could be used at the same time as a radiant ceiling for the room underneath (i.e. exposed concrete ceiling) and as a radiant floor for the room over the slab. This position in the slab ensures the ceiling radiates more heat than the floor so it does not exceed the maximum allowed temperature for a radiant floor. This system is also used to cool a portion of the load from the envelope. Special care was taken to control the humidity level in the building to ensure no condensation would form on the slab during the cooling mode.
A solar preheating system is used for domestic hot-water needs. This assembly comprises flat-plate collectors located on the roof of the building and is usable all year long, even during the winter when the exterior temperature is below 0 C (32 F).
Connected to the hydronic network and allowing the building and its occupants to ‘breathe’ are the ventilation systems. The strategy behind the ventilation network was to install a primary fresh air unit that supplies the air to secondary fan coil units distributed all around the building. This ensures the right amount of fresh air is distributed everywhere independently from the load and, therefore, reduces wasted energy.
Further, a double-duct secondary system is used to recirculate return air from common zones. Depending on the needs, this air compensates the exhaust in the laboratories (from the chemical fume hoods), recirculates interior zones, or exhausts through a heat recovery device. Combined with the radiant slab, it decouples the fresh air treatment and distribution from the air change requirement and the pressurization in the laboratory and from the temperature control.
All air-handling unit (AHU) fans are equipped with variable speed drives to respond to real-time ventilation requirements, including input from carbon dioxide (CO2) sensors in ducts and in high-density zones such as the classrooms and various learning centres.
The air entering the primary unit is pretreated by two heat recovery devices. The more efficient accumulation type is used on the ‘clean’ exhaust (not from the fume hood) and has a yearly efficiency of 82 per cent for sensible energy and 70 per cent from latent energy (latent energy is recovered and humidity is transferred from the exhaust air to the fresh air in the winter and from the other way around in the summer). The secondary device, a run-around glycol loop, is used on the chemical fume hood exhaust and has a winter efficiency of 40 per cent.
To increase the efficiency in the summer, the water collected on the fresh air cooling coil is evaporated in the exhaust. This device, though less efficient, is safer and has no risk of recirculating contaminated air from the exhaust into the fresh air.
A dedicated ventilation unit fed with fresh air from the primary unit is also installed for the biopharma area.
To reduce the use of electrical energy during the shoulder season, natural ventilation is used for all the common areas. When the exterior temperature is adequate, automatically operated windows are opened at both ends of the building in the hallway of every floor and at the upper portion of the sixth-floor atrium to create a stack effect throughout the building. During that mode, the ventilation units from these zones are stopped.
In terms of water, the building limits its potable water needs by recovering rainwater and by using efficient devices. Potable water consumption is reduced by 60 per cent. The recuperated water is kept in a large underground tank and is employed for the toilets throughout the building.
During the design, special care was taken to ensure easy maintenance for the various components. For example, all the decentralized fan coils are located directly on the floor in small closets in the hallways. The mechanical elements in the laboratories are exposed in the ceiling, and sufficient space has been allowed around the mechanical systems in the mechanical rooms.
During the construction of the building, more than 75 per cent of the waste generated was diverted from landfill sites. Also, construction materials contained an average of 15 per cent of recycled content and, as mentioned, the Gingko tree remains.
To complete the ‘cycle of sustainability,’ an interactive screen has been installed in the main lobby to explain the sustainable features of the building to students and visitors. Real-time building data and energy consumption are shown on the screen. This building is also part of an engineering course (due next semester) at the college in which the students will have to take real measurements on the building’s different HVAC systems to test their knowledge of the actual systems. Scale mockup air and hydronic systems are also being prepared for use as teaching setups to simulate the components of the building.
The total construction cost of the project is around $35 million—nearly a third of which is dedicated to electromechanical services. In this amount, roughly $1.1 million is specifically associated with energy efficiency. The return for these elements is estimated at less than eight years (further reduced to six years when considering utility grants).
With its many sustainable features incorporated into the integrated design process, this building was able to achieve Gold under the Canada Green Building Council (CaGBC) Leadership in Energy and Environmental Design−New Construction (LEED−NC) program earlier this year. It was also awarded first place in the New Building category at the Association Québécoise pour la maîtrise de l’énergie’s (AQME’s) 2014 Energia Awards, and First Place at the 2014 Contech Awards for Innovative Practices. It is currently being presented in the American Society of Heating, Refrigerating, and Air-conditioning Engineers’ (ASHRAE’s) Technology Awards contest where the project is being judged as finalist at the international level.
John Abbott College’s Anne-Marie Edward Science and Heath Technologies building is an example of sustainable practice through the integrative design process, diligent site management, great education opportunity, energy efficiency, and water use reduction. It demonstrates that by starting at the ‘root’ of a project and developing it upward with a great vision and a common goal, the results can often exceed expectations.
Pierre-Luc Baril, Eng., HFDP, LEED AP, is an associate at Pageau Morel et associés inc. in Montréal and is specialized in designing energy-efficient laboratories. He is certified as a healthcare facility design professional (HFDP) by the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE). Baril is actively involved in the executive committee of CSC’s Montréal Chapter. He can be contacted at email@example.com.
Nicolas Lemire, Eng., M.A.Sc. LEED AP, is president and principal at Pageau Morel et associés inc. in Montréal. He has more than 17 years of experience in consulting engineering. Lemire is certified as an HFDP by ASHRAE. He can be reached at firstname.lastname@example.org.
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