Hyde Park Public School

Top energy performer employs thermal mass of precast concrete

A proven product like precast hollow core slabs have gained new functionality and added value through their integration with the heating and cooling system of the Hyde Park Public School in Barrie, Ontario. Technology from Toronto-based Termobuild converted the precast floors into part of the HVAC system. The thermal mass of the hollow core slabs allows the building to tap into low-grade energy such as the body heat of students, or to pre-cool the building at night by storing most of the daytime cooling needs in the floors.

By Jack Laken

The Hyde Park Public School demonstrates how simple and instantly rewarding sustainable initiatives can be implemented to heat and cool buildings using precast concrete products and HVAC equipment.

The school has surpassed some of the performance benchmarks in the US Green Building Council’s Sustainable Schools program. The program assists school boards in evaluating their energy performance, monitoring progress, and providing the tools required to make substantial and lasting improvements.

Since 2007, Sustainable Schools has been reporting on the top performing schools across Canada, establishing the magnitude of energy savings potential and directing them to where these savings can be found.

Cutting energy consumption began in the design phase. For example, the school has a minimal exterior surface area to volume ratio to decrease heat loss. In addition, construction details were carefully designed to reduce envelope infiltrations, aided by an exterior layer of spray foam insulation. Many of the windows have an inserted heat film which increased the average glass insulating value to R9.6.

The Termobuild HVAC design combines heating and cooling, ventilation and energy storage into one system. As a result, the school requires half of the mechanical equipment — chillers, boilers, ground-source heat pumps or simple roof top units — as in a conventional building. This is important because mechanical systems represent a significant expense in building construction, as much as $25 to $40 per square foot.

Energy storage technologies are available in many buildings, with or without high levels of variable renewable generation. Recently Bill Gates noted that the main roadblock to implementation is high cost and complexity of energy storage. However, using the thermal mass of precast concrete for energy storage can offer a practical lower cost solution.

Precast hollow core heating and cooling
The system uses the thermal mass of precast concrete hollow core slabs paired with a ventilation system to provide heat in the winter and cool air in the summer.

In winter, surplus heat, generated from body heat, lighting, computers, sun radiation, etc., is captured, stored and released on demand.

In the summer, if the night temperature is cooler outside than inside, a simple ventilation fan draws in the cool air, circulates it through the hollow core slab and gradually discharges it by day as the building warms up. This radiant cooling dramatically cuts back on use of the building’s air conditioning.

PROJECT CREDITS
ARCHITECT Stafford Haensli Architects Incorporated
THERMAL MASS SPECIALST Termobuild Canada
GENERAL CONTRACTOR Aquicon Construction Co. Ltd.
STRUCTURAL ENGINEER Neumann Associates Ltd.
MECHANICAL ENGINEER Toews Engineering Ltd.
ELECTRICAL ENGINEER HCC Engineering Ltd.

PROJECT PERFORMANCE
- Overall energy consumption 8.7 ekWh/sq.ft./year which represents 40%+ energy savings compared to the average educational facility in North America [12.2 ekWh/sq.ft./year]
- Overall energy cost of approx. $0.60sq.ft. which represents 40%+ cost savings compared to the average educational facility in North America [$1.50/sq.ft./yr.]
- Reduced CO2 emissions representing 40%+ reduction compared to the average educational facility in North America.

Jack Laken, P.Eng. B.Sc., Founder of Termobuild - smart technology solution.

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