ASHRAE Journal - June 2012 - 82

2012 Technology Award Case Studies
Sustainable Strategies
• Underground air distribution with displacement ventilation diffusers at floor level • Radiant heating and cooling concrete slab • Natural/hybrid ventilation with leeward (downwind) vents at roof level • Ground source heat pumps, with windows acting as solar collectors with solar energy accumulated in the concrete slab during the day being released at night • Predictive controls to optimize energy storage and demand control • Active solid thermal energy storage (STES) in building’s concrete slab • Daylighting throughout the entire store, providing better color rendering of retail sports clothing • Pale (white) inclined roof reflects natural lighting on clerestory and increases daylighting • An underground cistern is used to collect rainwater and to feed the water closet. Also, all urinals are waterless huge quantity of product arrivals and displays in the racks. Table 4 shows those results. Montreal’s climate makes it possible to operate with a large quantity of outdoor air 47% of the time (outdoor temperature between 7.2°C and 23.9°C [45°F and 75°F]). The system was designed to take up to 100% of fresh air for free cooling. Thermal comfort was analyzed using ASHRAE Standard 55. A combination of radiant heating and cooling with good air distribution and controls provides a great degree of comfort for the occupants of the building. The ventilation unit also controls the humidity level of the incoming fresh air to avoid discomfort. To ensure adequate comfort level, a computer calculation was used to determine the comfort index (predicted mean vote and predicted percent dissatisfied) for various locations in the building (for example: retail area, cashier area, offices area). The sawtooth-shaped roof with clerestory was benchmarked for various building orientations to optimize the design and configuration of the solution. All mechanical system locations and installations were planned for easy access and maintenance. Ventilation systems are accessible from the stairways and main doors instead of roof hatches. The custom-built ventilation system is equipped with large tight doors to access filters and internal parts. All of the equipment is connected to a centralized direct digital control (DDC) network to easily optimize and track the system operation from a remote location. Alarms are routed to the operator terminal to report any problem in the system. A complete commissioning process per ASHRAE Guideline 1.1-2007 was started with an independent firm to assess the building design and to optimize the building operation, reducing the overall energy consumption.
82 ASHRAE Journal

• A solar collector system preheats domestic hot water in combination with the heat recovery device installed on the shower drain pipe • The new store consumes 57% less energy than the recommendations provided by the Canadian Model National Energy Code for Buildings • The geothermal field was positioned to limit the cut of existing full-grown trees • Propylene glycol was used in the geothermal loop for its limited impact on the environment in case of an accidental leak • 68.4% of construction residues were routed to recycling facilities • The quantity of refrigerants in the heat pumps is minimal and contains no CFC, HCFC (nor did any products used during construction) • The efficient use of active thermal mass with predictive controls reduces heat pumps from five to four • Reduction of 73% of potable water use with high efficiency fixtures and rainwater cistern

Parameter Dust Particulates Total Volatile Compounds Formaldehyde Carbon Monoxide

Concentration Indoors 40 µg/m³ 490 µg/m³ 48 ppb Null

Maximum Acceptable Concentration < 50 µg/m³ < 500 µg/m³ < 50 ppb < 9 ppm

Table 4: Indoor air quality analysis.

Heat pumps have been reduced from five to four.

The premium paid for energy-efficiency measures (for example: ground source heat pump, solar domestic hot water system, high efficiency heat recovery devices, etc.) is approximately $300,000 for a direct payback of less than 10 years compared with a conventional retail building. Annual energy savings are 427,842 kWh, which is equivalent to ±220 tons of CO2.
ashrae.org June 2012
ASHRAE Journal - June 2012

Table of Contents for the Digital Edition of ASHRAE Journal - June 2012
