By The AME Consulting Group
2012 TREE FOR LIFE AWARD & Award of Excellence: Jim Pattison Centre of ExcellenceBuildings Companies & People Building Mechanical & Electrical (HVAC) Systems
The Jim Pattison Centre of Excellence for Sustainable Building Technologies and Renewable Energy Conservation at the Okanagan College Campus in Penticton, B.C. was conceived to meet the urgent need for construction workers and site managers who...
The Jim Pattison Centre of Excellence for Sustainable Building Technologies and Renewable Energy Conservation at the Okanagan College Campus in Penticton, B.C. was conceived to meet the urgent need for construction workers and site managers who are skilled in the practices of sustainable building.
The 73,000-sq. ft. building comprises six large trades shops, classrooms, a demonstration lab, study areas, gymnasium, offices and support spaces, as well as a rooftop testing and viewing area for roof mounted systems.
One of the unique aspects of the building is that it is being used as part of the teaching curriculum. It has exposed HVAC systems, hands-on lab access to HVAC building systems, interactive building controls and live demonstrable data on building energy consumption.
The building targets LEED NC 1.0 platinum and the International Living Future Institute’s Living Building Challenge. The Living Building Challenge has seven performance areas, but for AME Consulting Group, the mechanical consultants, the most notable is to target net zero energy consumption. An additional Living Building Challenge is that no energy for the building can be from combustion of any kind.
Geo-exchange and solar
Penticton is located in the interior of British Columbia, a region with a dry climate and relatively hot summers and cold winters. Taking into account these conditions, several studies were completed to review the optimum building geometry, envelope and mechanical systems.
For the mechanical systems, AME proposed an open-loop ground source water-to-water heat pump system, with in-slab radiant heating and cooling, combined with a hybrid natural and mechanical ventilation system with heat recovery.
A solar hot water system provides domestic hot water as well as supplemental building heat. Excess heat from this system is rejected to the ground via the geo-exchange system. Both evacuated tube and flat solar panels were installed for demonstration purposes and comparison.
AME proposed using integrated hydronic PEX tubing as part of the concrete and wood composite wall panels for the gymnasium, rather than having hydronic pipes below the wood floor. Also, ductwork and displacement ventilation diffusers were integrated into the composite wall panels.
The building, including passive and active systems, was modeled in IES Virtual Environment by AME Group to determine the optimum design and compliance with ASHRAE 90.1, 55 and 62.1.
The ground source heat pump system extracts heat from the earth using pumped ground water from production wells. In summer the heat pumps remain off and ground water only is passed through the heat exchanger to reject the heat from the building (no refrigeration cycle is used). Free cooling helps to further reduce the energy consumption of the building.
The hybrid ventilation system uses mechanical ventilation with heat recovery when the outdoor conditions don’t allow natural ventilation through the operable windows. A roof mounted weather station includes a “green light” and “red light” system to indicate when to open or close the windows. Because this system requires an active response by the students and faculty, it increases their awareness of the building’s energy use.
Solar and wind assisted natural ventilation chimneys boost the natural ventilation. Control dampers on the chimneys open or close based on the wind direction to optimize the natural ventilation.
When the natural ventilation system is not being used, the mechanical ventilation system provides outdoor air via displacement diffusers with reverse-flow heat recovery units at the air handling units. The design intent of the combined systems is to reduce building energy use as well as provide optimal indoor air quality and comfort for the occupants.
Because the system consists of simple mechanical equipment such as hydronic pumps, fans and heat pumps, it minimizes the amount of maintenance and simplifies the building operation. Meanwhile, the operation staff have an integral role in educating students and staff about the impact of building use on energy consumption.
Overall the capital cost of the mechanical system was similar to that of a conventional HVAC system. In terms of its operational costs, modeling indicates energy savings of 64% over the baseline building (Canadian Model National Energy Code for Buildings). When the roof mounted solar photovoltaic power is included in the energy model, the savings increase to 92% over the baseline model. The carbon emissions reduction is approximately 330 tons of CO2 per year (equivalent to CO2 emissions from 34,000 gallons of gasoline consumed).
This innovative project was successfully completed within an accelerated construction schedule as well as on budget.cce
Name of project: The Jim Pattison Centre of Excellence in Sustainable Building
Technologies and Renewable Energy
Conservation, Okanagan, B.C.
Award-winning firm (mechanical
consultant): The AME Consulting Group, Vancouver, B.C. (Harold Stewart, Derek Schick, P.Eng., Jerry Chung, EIT)
Owner/client: Okanagan College
Other key players: CEI Architecture
Planning Interiors (architect, prime
consultant); True Consulting Group (civil), Applied Engineering Solutions (electrical), Recollective Consulting (sustainability), PCL Constructors Westcoast (general
contractor, project management);
Summit Environmental + Richards
Hydro Tech (geo-exchange system),
Swiss Solar Tech (solar).
Supplier: Viessmann (solar collectors)
Our greatest challenge as a building industry is to do our part to reduce greenhouse gas emissions. Mechanical engineers will play a crucial role if we are to succeed. This building team, and the mechanical engineers in particular, took on one of the most ambitious targets in our industry – the Living Building Challenge – and did so without sacrificing function, appearance or budget.