Utilizing building energy simulation to improve process load heat reclamation for a multi-sport athletics venue

Large, multi-use sports and recreational facilities provide a unique, yet challenging, opportunity for energy conservation due to their large process loads. The proposed paper describes the use of building simulation to aid in mechanical system and architectural design to improve heat recovery from process heat generation to satisfy building loads. The focus of this study is a recreational facility that consists of an NHL-size ice arena, 8-sheet curling rink, a gymnasium, change and restrooms, offices, library, fitness studios, a large glazed atrium, as well as 50 metre lap, leisure, outdoor and whirl pools. The ice plant providing refrigeration to generate and maintain the ice surfaces produces large amounts of waste heat when in operation. Traditionally, ice plant waste heat has been recovered for rink-related hot water loads only (i.e. snow melt pits, ice resurfacer fills for ice resurfacing, and sub-floor freeze protection), with the excess being rejected to the ambient environment. With this project, the proximity of the rinks and pools offers a unique opportunity for a more thorough recovery and reuse of the ice plant’s waste heat. When designing to reuse waste heat, difficulty lies in balancing the availability and grade of reclaimed heat with a corresponding building or process load. To accurately predict this balance, two building energy simulation tools were employed, one to predict building HVAC loads (eQUEST) and a second to describe the system energy flows (TRNSYS). Initially, hourly end-use process loads were determined based on applicable literature and historical data and knowledge gained from similar facilities operated by the regional parks board owner. These loads were then included in a whole-building energy simulation to determine overall HVAC and building energy consumption. A second simulation, specific to the building’s mechanical systems, was then used to calculate the dynamics of demand and availability of heat, taking into consideration the grade of heat available from the heat sources (ice plant, solar hot water collectors, heat recovery, and building heating equipment). The results of these complimenting simulations aided in determining the design of the building’s mechanical systems including sizing a hot water storage system intended to balance the inherent time lag. This paper describes the procedure employed to predict the transient nature of athletic facility process loads, the combinination of multiple building simulation tools to predict and balance heating loads with process waste energy, and the necessary integrated design process required.