Liverpool University has almost completed a long-term M&E upgrade that has seen Stokvis plate heat exchangers specified to replace nearly all of the existing calorifiers used to provide hot water to its buildings.
Over the past 10 years, the University has taken its old calorifiers (each used to store up to 3,000L of hot water) out of service as they reach the end of their service lives or become uneconomical.
The calorifiers have been replaced with plate heat exchangers, usually accompanied by a 300-500L buffer vessel, to provide hot water on demand.
“Stokvis plate heat-exchangers are our preferred solution for hot-water generation” confirmed Jonathan Cave, senior mechanical engineer at Liverpool University’s Facilities Management department.
“We don’t wait until the equipment falls over; when a calorifier is costing too much to maintain or is nearing the end of its service life, we replace it”, says Jonathan.
The problem with keeping a large volume of water stored at high temperature for long periods is that an outdated calorifier can be a breeding ground for Legionella bacteria.
A plate heat exchanger, however, produces hot water on demand at a reliable temperature. The buffer vessel maintains a small supply for immediate use and the system constantly recirculates the water through the system to prevent stagnation and cold spots from developing.
Liverpool University has a large city centre campus served by a CHP district heating system, which Jonathan says is perfect for feeding into the Stokvis units.
However, the University has around 300 separate buildings of various types, ranging from laboratories to student accommodation, in its property portfolio.
Within the last year alone, Stokvis Econoplate packaged plate heat exchangers have been installed in five different buildings, including the Mount Pleasant office building, the Sports & Fitness Centre, the Victoria Building, Harold Cohen Library and, most recently, the kitchen of the Guild of Students.