In 1995 Lockhart Industries designed, built and installed their first chilling system to keep salmon eggs dormant and from hatching for a salmon hatchery on Vancouver Island, B.C.
The system had relatively high initial capital costs but allowed for greater versatility in first feeding and allowed for two batches of eggs to be hatched that winter. This system paid for itself virtually that winter. That summer Lockhart Industries was asked if they could retrofit and adapt the system to heat the water for the fry to decrease mortality, increase feed conversion factors and accelerate growth.
They then embarked on an arduous task to ensure the same piece of equipment could be used to heat the coldest water at the start of heating, heat the water up and hold final temperature, chill the water at the coldest point to hold the eggs dormant and then slowly decrease the chilling to allow the eggs to hatch. This all had to be done so as not to harm any of the biomass at ANY time, to ensure the long term safe, efficient operation of the refrigeration equipment and this all had to be accomplished while maximizing the use of energy.
Lockhart Industries found that the task was very challenging but with the use of recuperative heat exchangers and custom built refrigerant condensers and evaporators they achieved results that astounded both themselves and the staff at the hatchery. Lockhart Industries achieved heating rates of the water, when balanced, that reduced the cost of energy down to 10% of the projected cost using electrical on a once through system.
Due to the remoteness of most sites and the extensive utilization of propane boilers, which is the highest cost per BTU, the savings of the GeoExchange heat pump system are even higher when compared to the most popular heating system. Paybacks as quick as ONE heating season have been realized with subsequent installations.
Since the heat generated in a conventional heating system is usually thrown down the drain at the end of the cycle, the system designed and built by Lockhart Industries recovers the majority of this already paid for heat then scrubs the remaining heat out with the refrigeration (GeoExchange heat pump system) system which operates at 6 times the efficiency of conventional heating (COP 6). When it comes to maintenance, the GeoExchange heat pumps are VERY low maintenance. The refrigeration system is sealed and needs no “topping up” or special maintenance. As listed by ASHRAE (American Society of Heating, Refrigeration, Air Conditioning Engineers) the GeoExchange heat pump has the lowest maintenance factor of any heating system available today.
Remote DDC control systems utilizing a standard PC and monitoring capability can also be added to the system. This enhancement facilitates the very close control of the biomass and optimization of energy consumption. These systems can also be tied into to spread sheets to trend the performance of the system to performance of the biomass. Alarms and actions can be pre-programmed to alert site personnel or service companies to problems should attention be needed for anything from water flows to necessary temperature levels. This use of a standard PC complete system monitoring, as well as a database of accumulated information, can be utilized in present and future batch performance.
