In 2012, Purdue University’s Biochemistry department noticed that the vacuum system in their building was eating a hole in the budget. Analysis by design firm Loftus Engineering showed that running the vacuum system had annual operating costs of about $400,000. On top of the astronomical costs, researchers and students were not able to depend on the vacuum system to support their work; some days the vacuum would be weak, some days it did not work at all.
This central vacuum system was installed when the building was constructed, several decades ago. Because Purdue’s campus has a central steam plant, a steam ejector system was selected as the source of vacuum, since the steam was an effectively ‘free’ resource. Loftus’ analysis highlighted that even though the water and steam were low cost ($73,000/yr. to generate steam and $17,000/yr. for the water from onsite wells), the cost of disposing of the waste water had not been considered. Water disposal cost twenty times more than the source water, accounting for the balance of the $400,000 annual operating costs. Loftus’ analysis also highlighted that the steam ejector system consumed nearly 60 million gallons per year, which imposes a substantial environmental cost, on top of the economic cost.
To eliminate the exorbitant operating costs and provide a reliable vacuum system for the Biochemistry Department, Loftus considered two options – a central vacuum system and VACUU·LAN® local vacuum networks. Purdue elected to go with the local vacuum networks because of their ability to provide deep, stable vacuum with greater reliability, low maintenance requirements and minimally disruptive installation in the working labs.
The result is that Purdue has reduced the operating costs from around $400,000 to $5,000 per year. The new vacuum systems paid for itself in less than one year. The systems were installed ahead of schedule, with minimal disruption to the researchers. The VACUUBRAND pumps used provide adjustable vacuum that is both more reliable and deeper than was available through the old system. And Purdue has been so happy with the performance of their VACUU·LAN vacuum systems that it has been adopted for many other lab facilities on the campus since the 2012 installation.
