Regular session, intersession, summer session – for years, the heating and cooling systems in several HCL libraries ran virtually all day, whether the buildings were open or not.

As part of HCL’s commitment to sustainability, the library recently worked with contractors to create three different schedules for the HVAC equipment – one for regular session, one for intersession and a third for summer session. The project took nearly six months to complete, and cost just under $5,000, but is expected to save more than eight times that amount in annual energy savings.

Initiated by HCL Operations Director Paul Bellenoit and Associate Librarian Rebecca Graham, Harvard College Library Sector leaders for the University Green House Gas Reduction Program, the scheduling changes are one of several ways the libraries are working to help Harvard meet its sustainability goals. Other projects include the installation of occupancy sensors and compact fluorescent bulbs in dozens of areas, replacing bottled water coolers with filtered water dispensers and installing water-conserving bathroom fixtures.

While the new system saves HCL thousands in unneeded heating and cooling costs, it also dramatically cuts greenhouse gas emissions, Andy Laplume, Assistant Director for Project/Building Systems Management said.  

Though the end result is akin to the programmable thermostats installed by many homeowners, the project’s size presented a host of logistical challenges – Widener Library alone has 14 air handlers, as well as multiple chilled water pumps, boilers and associated mechanical systems – the timing of which all had to be coordinated.

 “The timing on the mechanical equipment is now set to reflect the operating hours of the library,” he said. “I can go into the computer and toggle between regular session, summer session and intersession by clicking on one button, and all the mechanical systems take on the new operating schedule.”

 The new system coordinates the heating and cooling systems in Widener, Lamont and Tozzer libraries, but doesn’t include Pusey or Houghton libraries, because their systems are either too old or need to run independently to protect collections.

In an additional effort to save energy, all Faculty of Arts and Sciences buildings – including HCL libraries – earlier this year adjusted their thermostat settings, increasing summer temperatures to 75 degrees, and lowering winter temperatures to 68 degrees.