MISSOULA, Mont. — Butte High school in Missoula is projected to save more than $75,000 on energy costs annually following the recent completion of a multi-phase energy retrofit. Also anticipated to enhance the school’s overall learning environment, the improvements included everything from replacing the school’s HVAC system to upgrading an aging and inefficient boiler.

Butte High School partnered with McKinstry — a national firm that specializes in designing, constructing, operating and managing high-performance buildings — to complete the phased project. The firm’s Missoula- and Bozeman, Mont.-based offices audited, re-designed and modernized the high school’s building systems, and work was completed this month, according to a statement by the firm.

The final round of work entailed replacing the entire heating, ventilation and air-conditioning system within Butte High School’s 56,723-square-foot annex and administrative offices with a new variable refrigerant flow (VRF) system, and revising and replacing heating control valves to allow the high school more precise control over heating and cooling.

The school will enjoy added energy savings with the installation of heat recovery units that can simultaneously heat and cool different zones of the annex depending on need, according to a statement by McKinstry. Students, teachers and staff using the school’s counseling and attendance office will benefit from improved thermal comfort year-round.

“These improvements not only help Butte School District stretch its energy dollars, but will provide a healthier, more comfortable learning and working environment for all school occupants,” said Daniel McGee, account executive at McKinstry, in a statement.

Butte High School principal John Metz added in a statement that the school is “proud to provide such efficient and cost-effective solutions.”

Energy and utility costs generally account for 20 to 40 percent of a school’s maintenance and operations budget, and can be much higher if equipment is beyond its useful life. In a statement, McKinstry referred to a recent USGBC report showing factors such as thermal comfort “affect the stress levels, health and well-being of occupants in schools,” and can influence student achievement.

“Prior to modernizing the school’s building systems, two neighboring classrooms could experience a temperature difference of 20 degrees or more. Now, we’re keeping classrooms heated and cooled consistently as needed, while circulating a healthy level of fresh air,” said Jed Hoopes, head of maintenance for the Butte School District, in a statement.

Butte School District and McKinstry first partnered in 2009 on an energy audit of Butte High School, which led to state grant and district funding for replacing the 1960s-era boiler plant in the annex building and the installation of digital energy controls in the four-story academic building, completed between 2010 and 2012. In 2013, energy and operational savings from previous projects were leveraged to build out additional administration space in the annex.