Westhills Recreation Centre: innovation and cutting edge technology in North America

By Pilar Aleu, Apr 28, 2015, 14:28 3 minute reading

The Westhills Recreation Center project in Langford received first place in the New Public Assembly building category of the ASHRAE Technology Awards 2015. Designed and installed by Accent Refrigeration, the project is the first in the region to employ ammonia heat pumps to recover waste heat from the ice rinks and use it to heat a housing development and is one of only a few ammonia based air conditioning systems.

At the ASHRAE 2015 Winter Conference, which took place from 24-28 January 2015 in Chicago (Illinois, U.S.), Accent Refrigeration received first place in the New Public Assembly building category of the ASHRAE Technology Awards 2015 for the Westhills Recreation Centre project. Owned by the City of Langford (British Columbia, Canada), the building features a 75,000sq.ft (6,968 m2) recreation facility including a National Hockey League size indoor ice rink, an outdoor ice rink, a skating trail, a bowling alley, offices, and a restaurant.

Ammonia heat pumps to minimise natural gas consumption whilst reducing electricity expenses

Langford has one of the highest natural gas prices in North America therefore the main objective of the Westhill Recreation centre development project was to eliminate fossil fuel consumption whilst minimising electricity expenses. To do so, the project involved the design and installation of an ice rink refrigeration system that provides all heating and cooling, dehumidification and hot water for an entire recreation complex.

Started in 2010 and commissioned in September 2012, the total construction cost was $13,500,000 (€12,438,740) with $9,000,000 (€8,293,450) granted by the Building Canada Fund. The new technology has allowed for total energy savings of $109,702 (€100,350) and an investment payback period of 2.8 years prior to the energy sharing with the housing community.

Waste energy used to supply heating demands of housing community

Even with its extensive use of energy, only 40% of the waste energy is required within the complex; the remaining 60% is pumped 365m to a housing development where it is used as an energy source for household heat pumps. The project represents the first total integration between an ice facility and an entire community. Thanks to this system, no energy is wasted.

As the waste heat from the ice rink can only supply a portion of the required heating in winter, Accent designed two 180 ton VDF-driven ammonia heat pumps to supply the balance of heat to the community. The ammonia heat pumps use a geothermal field below a soccer field as the energy source and only required in the winter. They operate at a COP ranging from 8 to 15. The heat pumps maintain the housing energy loop at a constant 60°F (15.55°C) which results in very favourable COPs for the household heat pumps. If natural gas were used instead, the average energy value sent to the community would be of $41,470 (€38,088).

Westhills Recreation Centre HVAC&R system configuration

The installation is the first in North America to use ultra high efficient reciprocating compressors and the first total integration between an ice facility and an entire community. The centre is also the first in the region to use ammonia heat pumps to heat a housing community and is one of only a few ammonia based air conditioning systems.

Main features of the installation include:
  • Use of variable speed drives in refrigeration compressors and brine pumps. As a result, compressors operate at their maximum Coefficient Of Performance (COP), while centrifugal brine pumps help to reduce electrical consumption by modulating their speed and taking advantage of the Pump Affinity Law
  • The outdoor ice rink offers the best-possible energy balance by providing additional waste heat during peak heating demand
  • Ice rink sub-floor heating system for thermal energy storage, which can be used for heating in colder periods. In addition, 6” of R-5 insulation board between the ice pad and heating floor, as well as around the outside walls were used, enabling to increase the temperature of the subfloor to 75 °F (23.89°C)
  • 15 HVAC units and 2 heat recovery ventilator’s interspersed throughout the complex
  • Domestic hot water provided with an ammonia heat pump at a COP of 4.28 in winter seasons
  • Tailor-made desiccant dehumidifier using 2 coils in series to regenerate the desiccant wheel
  • Ultra-high efficient VDF-driven compressors to meet ice rink’s needs in winter and AC needs in summer. The compressors have a cooling COP of 4.62 in winter and an AC COP of 15.1 in summertime. With 100% of energy being recovered, the compressors have a combined heat/cool COP of 10.2 in winter
  • Building automation system used to minimise energy consumption

As a result of these initiatives, the Westhills Recreation Centre has not used fossil fuels, other than in the kitchen, since the complex was commissioned in 2012.


By Pilar Aleu

Apr 28, 2015, 14:28

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