Grant: Research Tools and Instruments - Category 1 (<$150,000)

The Department of Biological Sciences, UofA contains a world-class aquatics facility housing various fish species. These animals are essential for the ongoing NSERC-funded research programs of the nine investigators participating in this application. Fish are cold-blooded vertebrates whose body temperature matches that of the water temperature and are dependent on thermally regulated water for their survival. Approximately ten thousand fish are maintained in our aquatics facility and with the recent hiring of an environmental toxicologist (K. Tierney, 2009) these numbers will increase. Depending on the fish species being studied and the types of experiments performed, incoming water from the City of Edmonton needs to be consistently cooled to 10-17 C for trout, salmon, carp, and goldfish or warmed to 25-28 C for zebrafish and catfish. The cooling and heating of this water is accomplished using a brine-based recirculation system and steam, respectively. Water cooling is facilitated by a vapour compression refrigeration system that uses a 30 tonne chiller unit designed to remove and discharge heat from a circulating brine solution. Major components of this system are the chiller unit, a refrigerant evaporator, and a brine circulation pump. In September 2009, detailed inspection of the brine chiller system found that it has developed leaks due to corrosion in the evaporator that allows brine to directly enter and cause irreversible damage to the chiller. Oxygenated brine and cavitations also corroded the pump beyond repair preventing it from adequately circulating brine. This is not an issue during the winter months (October-March), however, in the spring and summer this damage will completely inhibit our ability to chill the incoming water. In this proposal we are requesting funds for the purchase and installation of two evaporators and two pumps required for our brine-based cooling system. The additional evaporator and pump will serve as stand-by units allowing for routine shut-down and maintenance, a strategy that will maintain our cooling system in operation for more than 10 years. We already have acquired a new 30 tonne brine chiller to replace the damaged unit and only installation costs for this item is requested.