New Glasgow Hospital

 

Nova Scotia’s Health Authority has a small laundry department that provides laundry services to a New Glasgow Hospital.  Typically, the laundry would be in operation eight hours a day, five to six days a week.  During that time, the three washers drew domestic hot water (DHW) for approximately four hours at 1,000 L/wash for a total of 3,000 L per hour/machine. The DHW tank had been fired at 15 psig with a steam coil and regulator to keep the temperature at 140 degrees F. Water temperature was then boosted through a steam injection process to the 160 degrees F. temperature required for washing. Overall, the system was quite energy inefficient.  Having to keep 5,000 liters of water heated 24/7 to accommodate a four-hour daily usage window, coupled with the significant steam loss characteristic of the steam injection system, was evidence enough that the overall system was very energy inefficient.  As part of their membership in the Energy Innovators Initiative, the Health Authority had deposited an energy Management Plan with Natural Resources Canada.  Included in the plan was a review of all DHW operations at the New Glasgow Hospital with the thought of replacing older, less efficient equipment.  However, the capital cost of replacing functioning equipment strictly for energy efficiency reasons is always a hard sell to upper management. With an eye towards making a sound business case for the upgrade, in-house technical staff audited the laundry operation and developed a proposal to replace the existing DHW tank with an instantaneous hot water heating system. When the proposal revealed evidence to support a payback of less than two years, the DHW project was given the thumbs up by the senior leadership team and a Spirax Sarco EasiHeat instantaneous DHW heat exchanger was installed.  The new compact unit occupies only 1.2 m3 and is capable of delivering 80GPM of DHW at constant temperature even when sudden and wide load changes occur, as is often the case in laundry operations. The steam supply is set at 15 psig and the water temperature is set at 165 degrees F.  The unit is so efficient that it has now been connected to the hospital’s main DHW tanks to ensure the unit has adequate load during the laundry down time.