Multifilm has undertaken several sustainability projects within the last few years, which have helped the company become more efficient and profitable. One of them consisted of replaced a 300-ton, 20 year old rooftop chiller that handled process cooling with a completely custom geothermal process cooling and HVAC system by GeoCool.
A geothermal design consists of a system in which groundwater is pumped into the building and passed through a number of heat exchangers before being pumped back into the ground. The heat exchangers serve the plant’s four cooling areas with cold water as well as a number of air handlers that provide heat or air conditioning to the building. Variable-speed drives regulate the water flow depending on how many machines are running and how much cooling is required. Therefore, the geothermal system will only run as much as needed to maintain these set points—it will run even when the machines are not running if the plant is calling for air conditioning. If everything is off and nothing is calling for cooling then most everything will either shut down or reduce to absolute minimum speed. There is never anything wasted with this system.
The supply wells are combined into one water flow inside the building and split into four separate “water loops;” one air-conditioning loop, one make-up air loop, and two production loops. Water is prioritized to the process that requires the coolest temperatures, and moves through the production process based on temperature need, using the energy to its fullest potential before being rejected back into the ground.
The brains of the system are the software and electronics controlling all parts, which are essentially just pumps and valves. The system is demand driven; meaning when a machine is calling for cooling, water is directed to that machine. Production has first priority, with air conditioning being the last to get cooling should there not be enough capacity. The functions are based on variable speed drives on the well pumps. When demand is very low, only one well pump will run. The same concept is used for the cooling loops where the pump speeds are dictated by the temperature rise across the chill rolls.
Multifilm’s geothermal system has been in operation since September 3rd, 2010. Extensive measurements by the local energy provider and Multifilm staff indicate that after switching to geothermal cooling, we has saved nearly one million kWh per year.
The geothermal system utilizes renewable energy, is completely Freon-free, and has reduced the company’s energy consumption, thereby lowering the overall carbon footprint. In theory, the system should last indefinitely; pumps, valves and heat exchangers can be easily replaced. Unlike a traditional chiller, with geothermal there are no big-ticket items that can break. Lowered operational costs have, in turn, made the company more competitive and increased profitability, encouraging future investments and safeguarding the future of Multifilm, its employees and their families.