How does one modernise the HVAC system at a manufacturing plant without the luxury of downtime? You turn to Schneider Electric, of course. This was what the Norampac paper box factory in Quebec did when faced with the challenge of upgrading its heater system used to keep its vast production floor warm.
Keeping Wires to a Minimum
Spread over almost 40,000 sqm on a single floor, the paper box plant located in one of the most snow-rich cities in Canada is served by some 25 steam coil air heaters. Each “dumb” air heater operates independently and is wired to a nearby mechanical thermostat for temperature control. As you might expect, this is less than ideal in terms of either energy costs or a comfortable working environment.
Aware of the system’s limitations, management was keen for an upgrade. However, they were adamant that production downtime is not an option. This meant that any installation or deployment work around the heaters had to be performed without impacting facility operations, substantially increasing the difficulty of upgrading them.
The reason is simple: Traditional control options revolve around the use of wires and relies on the installation of physical conduits and control lines to each heater. This translates to some amount of non-trivial and unavoidable disruptions to operations. So how about going wireless? The truth is that not all wireless technologies work well in a factory environment, especially given the large and dense equipment found in paper box plants.
After a thorough evaluation of the situation, Schneider Electric deployed a wireless system to control the heaters. ZigBee was chosen for its inherent support for mesh networking which offers greater reliability for the challenging environment. ZigBee-capable controllers from Schneider Electric were installed on two-thirds of the heaters for wirelessly control, while the remainder were hardwired to ZigBee transmitters.
Doing More With Less
ZigBee transmitters were also integrated with an existing IP system used in the office section of the facility, doing away with the need to purchase and install additional networking equipment. This worked because the Schneider Electric controllers are based on open protocols and can work with standard IP networks without the need for specialised gateways or protocol converters.
Norampac now has an integrated heating system with centralised monitoring and control for increased worker comfort. Temperature setpoints could be established ahead of time based on work schedules – and the weather – allowing the paper box manufacturer to keep a close eye on energy costs.
Indeed, the upgrading project culminated with a 25% reduction in heating costs that adds up to tens of thousands of dollars annually. Moreover, taking the wireless route also proved to be cheaper. According to an estimate by a contractor, going wireless resulted in savings of US$45K (SG$61K) on labour and material from conduits and wires that didn’t have to be installed.
You can read more about this project here (free download).
