Cardboard Factory Connects Heater Controls with Wireless Communications
The Norampac cardboard box factory of pulp and paper giant Cascades Inc. wanted to reduce heating costs and improve employee comfort. The factory in Montreal, Canada, has 25 steam coil air heaters spread over 427,000 square feet. Each heater was controlled by a local mechanical thermostat without great results. The size of the factory and requirement to install conduits for wires were excluding the traditional “wired” control option. It would have been too costly and would have interfered with factory operations, which is out of the question.
Nevertheless, the objective was to reduce the energy bill associated with heating and increase worker comfort by centrally managing temperature set points according to schedules. But the installation should not affect facility operations in order to minimize direct and indirect costs. The solution’s basis was found in the existing BACnet IP building management system, which managed the small office section of the factory.
Using EnOcean relays, controlled wirelessly by CAN2GO wired and wireless controllers, themselves equipped with embedded BACnet IP gateways, the mandated contractor was able to install the missing link between the heaters and the BACnet building management system – without extensive wiring costs or significant downtime.
Wireless Sensors Are Self-Powered
EnOcean’s wireless sensor modules harvest the power they need from locally available sources – such as linear motion, indoor light or small differences in temperature. This ambient energy is converted into usable electrical energy to power the transmission of wireless signals between devices. In terms of real-world applications, this self-powered wireless link can be used to report a disturbance in production machinery, for instance. EnOcean-enabled devices operate autonomously, there are no batteries to check or replace, so they are also entirely service-free and highly flexible to install.
In the factory, 16 heaters are now controlled by EnOcean-based relays communicating with CAN2GO controllers. Nine others are hardwired directly to controllers. All controllers communicate wirelessly to each other using their ZigBee wireless mesh capabilities; limiting wiring to a minimum and allowing a robust mesh backhaul, even in a dynamic environment with large, dense core paper reels. One controller is connected to the LAN, sending the wired and wireless end-devices as BACnet objects to the existing third-party BACnet IP system – no gateway or software needed.
40 Percent Less Time to Install
Putting all these installation and integration advantages together, the contractor estimated spending 40 percent less time on the job then if it had been a completely wired retrofit. 4,000 feet of conduits and wires were saved. All in all, the total estimated savings including labor and materials reach $45,000 for the 25-controller project.
And the energy savings are respectable as well: Due to the new intelligent system, integrating the two wireless industry standards BACnet and EnOcean, the factory could save $37,000 in energy costs in the first year and $42,500 in the second year as of March 2012.
“The system allowed us to centralize temperature control and generate interesting energy savings,” says Fabien Demougeot, engineering technical supervisor, Cascades Inc. “The installation was done without disrupting our operations, which was very important. This would’ve been impossible with traditional wired control solutions.”