Smith Brasher Hall Ground-source HVAC System to Save Energy, Money

December 13, 2016 -- The new ground-source heating and cooling system and other improvements that are part of the major renovation of Smith Brasher Hall on Main Campus are expected to save CNM about $96,480 annually. That includes a roughly 33 percent reduction in electricity costs and a total elimination of gas charges.
Smith Brasher Hall Ground-source HVAC System to Save Energy, Money

Dec 13, 2016

“These are dramatic numbers compared to the traditional method of heating and cooling,” said Molly Blumhoefer, CNM’s Campus as a Living Lab and Sustainability Project Manager. “Imagine what could be saved if CNM installed the system in all of its buildings.”

The new ground source heat pump heating and cooling system is a series of vertical wells drilled into the ground to use the earth as an energy source or “heat sink.”  This “closed loop” transports energy to and from the ground using water in the piping.

The energy source for the heat pumps comes from the ground under the parking lot outside of  Smith Brasher Hall. Under the parking lot, 160 boreholes have been drilled at 25-foot intervals. Each borehole is 300 feet deep. A pipe loop placed in these holes draws energy for the heat pumps from the ground using water as the circulating agent. The year-round average ground temperature is about 68 degrees. The pipes, which are made of high-density polyethylene, are grouped, leading to a small mechanical pump room on the ground floor. 

The ground source heat pump system is all electric and does not require gas fuel as in traditional heating, ventilating, and air conditioning (HVAC) systems. These traditional systems reject the heat in the summer into the atmosphere -- losing heat. In the winter heat is added using gas-fired equipment like a boiler.

“The ground source heat pump system allows for us to store summer heat in the ground and use it in the winter,” said Abbas Shirian, mechanical engineer with Bridgers & Paxton Consulting Engineers, which is overseeing the heat pump project. “We are capturing the heat and putting it back in the building with no need for natural gas. Electricity is used to pump the heat/cool water through the system and into the building.”

He added, “The amount of electricity used to run the heat pumps is also substantially less than what would be needed to cool in the summer months, thus curbing our consumption of fossil fuels, reducing our impact on the climate and mitigating energy costs.”

Two other buildings on CNM campuses already are being heated and cooled using ground source heat pumps -- the Rio Rancho Campus building and Westside Phase I on the Westside Campus.

Shirian noted that CNM ranks high in the number of buildings with ground source heat pump systems – a total of three buildings. Santa Fe Public Schools has two schools and one in design. Clovis Municipal Schools has two schools, while Rio Rancho Public Schools V. Cleveland High School is outfitted with the new heating and cooling system.

Smith Brasher Hall is a 61,400 square foot two-story steel frame with brick veneer classroom building constructed in 1982. Although it is temporarily unoccupied due to the renovation, it typically houses the School of Business & Information Technology (BIT) which includes programs such as Accounting, Business Administration and Computer Information Systems. It also has computer classrooms, general classrooms, BIT administrative offices and an auditorium.

Smith Brasher Hall is expected to reopen in January 2018.