Geothermal Heating System to Be Considered for Montgomery Township Community Center

Geothermal heating may be the way to go for the HVAC system in the proposed 40,000-square-foot Montgomery Township Community Center at Stump and Horsham roads.
On Monday, supervisors got an update from architect Jon Trump and the steering committee on proposed exterior finishes and two proposed alternatives for the HVAC system for the site: packaged and split gas or ground source heat pump.
"The board decided to continue to pursue a geothermal system for the community center building," said township Manager Larry Gregan. "The engineer will move forward with the boring of the wells that needs to be done and evaluate the depths needed in order to reach the water table."
Gregan said the engineer will determine whether it costs too much to bore down into the water table and whether or not the well has enough conductivity.
"The board expressed that so long as it is within the cost parameters included in the original estimate for the project—around $400,000," Gregan said. "If it costs more, they would reconsider."
Gregan said conductivity of the water affects how water can loop through the heat pump system. 
The geothermal system would require boring of 40 450-foot holes throughout the site, as well as piping, manifolds and heat pumps throughout the building.
A steering committee review revealed that the township building uses $2.69 per square foot per year. A gas system at the community center would use $1.46 per square foot per year, and a geothermal system would use $1.25 per square foot per year.
Derek Fink, P.E., of McHugh Engineering, provided a cost comparison and payback analysis for the two systems to Trump, an architect with Kimmel Bogrette Architecture + Site in Conshohocken. The energy model used an approximate design cooling load of 100 tons and a design heating load of 1.3 million BTUs per hour.
Based on those values, the firm calculated a 40-year payback on the installation of a geothermal system over a gas-fired system, equal to about $8,200 a year in cost savings.
The energy cost savings is much lower, according to Fink, but that is based on the current low cost of gas as it relates to electricity and the installation cost for geothermal. 
Fink estimated construction costs for a packaged and split gas system at $800,000 versus $1.2 million for the geothermal system. Total annual estimated energy usage would be 2.027 million kBTUs for gas and 1.08 million kBTUs for geothermal. Total annual HVAC energy usage is estimated at 1.452 million kBTUS for gas and 536,000 kBTUs for geothermal.
The gas system is estimated to cost more in HVAC energy than the geothermal system: $25,306 versus $17,252. There is no payback estimate for the gas system.
The steering committee found that neither solar nor wind power are options, as there is a current lack of rebates and grants.
Daylight harvesting and motion detectors would be used for lighting control. All lights would either be LED or fluorescent.
Trump on Monday also reviewed the three major exterior building components proposed for the building.
One is a synthetic stucco system for the back of the building. A metal panel is proposed for the front entrance, colored blue. The third building material for the exterior is a wood-type phenolic panel which would match the township administration building across the street.