The Charles Machine Works Inc. upgrades its campus with geothermal system, Pt. 2

Dec. 17, 2013
“As a company, we’ve made a living out of serving the underground construction industry, and to stay on top of the latest trends and understand the newest innovations, we figure there isn’t a better way than to install them at our own facilities,” says Tony Guinn, plant engineer for CMW.  According to Guinn, he and others at the company initially familiarized themselves with geothermal system concepts via relationships with nearby Oklahoma State University, where the International Ground Source Heat Pump Association (IGHSPA) is headquartered.

After extensive consultation and collaboration with the design team, Stolhand determined the best solution to achieve all of CMW’s operational and cost-saving needs was to replace the antiquated chiller and boiler with an energy-efficient heating and cooling exchange system powered by a geothermal field.

The new heat pump building next to the old chiller.

The addition of a mechanical building to house the new HVAC equipment also enabled Stohland and his team to complete construction, installation and initial testing of the new mechanical system before it went online.  This meant that heating and cooling were unavailable for only for a few days while the team disconnected existing mechanical system piping and reconnected the geothermal pipes.

Stolhand specified three 50-ton, six-pipe ClimaCool SHC onDEMAND modular chiller units from neighboring Oklahoma-based ClimaCool Corp for several reasons.

“I’d been to training with Air Products Supply and was highly impressed with the unit’s ability to generate heating and cooling simultaneously,” says Stolhand.  “The project goal was to save money, and a system like this that can blend energy versus just blast heat or cool seemed like the way to get that job done.  Also, the comfort level of this type of system is exceptional, especially when considering the design of the building, which includes two levels of an open floor plan and a south-facing wall made entirely of windows.” 

According to Stolhand, the SHC onDEMAND units’ ability to allow any module to be indexed for heating or cooling regardless of its position in the bank, providing optimum module/compressor run time equalization, was also viewed as a significant benefit.   

Initial geothermal field drilling for the project began in September of 2011, simultaneous to digging for new French drains on the north side of the product development center building.  “This was our first vertical loop field geothermal project on the campus,” says Guinn. 

In all, the field includes 168 400-ft. deep boreholes with HDPE double U-bend pipe installed throughout.  The loop field was completed in March of 2012, after which the chiller units were installed, and shortly thereafter initial flow testing was conducted.  

In keeping with its tradition of striving for ingenuity in product development, CMW planned the geothermal field so that one half initially serves as a test field to evaluate new drilling equipment.  CMW is experimenting with drilling styles to obtain data that will improve the efficiency of borehole drilling and loop installation, which are the most expensive facets of geothermal systems.  Guinn adds, “We’ve been operating on only half of the complete borehole field to date, as Ditch Witch is using part of the field for performance testing.  When the testing is complete, we plan to use the full capacity of the field.”

The drilling was conducted in tandem with the construction of a separate foam-insulated 20-ft. by 24-ft. mechanical building to house the new chiller units and ancillary HVAC system equipment.   In addition, an underground vault made of waterproof polyethylene was constructed to house the geothermal ground loop manifolding system. 

Drilling of the bore holes begin for the vertical loop field geothermal project.

“With our original HVAC system, the chiller was external to the building, and the boiler, which we removed, had been installed in the shop,” explains Guinn.  “We really needed a separate space for the new equipment, and also had a goal of making it a showplace of sorts, to use as a model for how this innovative system looks and operates.” 

According to Guinn, the building’s dual steel wall construction was designed to be highly energy efficient, as well as provide a clean, finished look for those visiting the space.

Stolhand and the design team also determined the production development center’s existing controls system, considered state-of-the art when originally installed when the building was constructed in 1978, should be replaced with a web-based building automation system (BAS).

“The new BAS provides much more control than the previous system, and really brought mechanical operations to a whole new level in the building,” says Mark Furgason, sales and service manager at Automated Building Systems, which designed and installed the BAS.

According to Furgason, the system includes a graphical floor plan of the building that shows all zones and readings from their associated temperature sensors.  It allows Guinn and others at CMW to monitor temperature in real time, as well as easily make any necessary adjustments, to ensure all zones operating with optimal efficiency while delivering desired comfort levels.

“The system allows you to adjust operations either onsite or remotely from any web-based device, including a computer or smart phone, and can also send alerts about system operation changes or problems directly to Tony via email or text,” explains Furgason.

“After the commissioning phase, the ClimaCool system has performed very well,” Guinn says.  “We locked the thermostats at 73°F to eliminate user fluctuations during summer heat waves, and the system kept the building very cool and comfortable at that temperature.

“We are still waiting to see what happens when the system’s been operating longer-term, but we expect that we’ll be seeing about a $50,000 annual savings in operating costs,” Guinn says.  “This is much in part due to the highly energy efficient operation of the geothermal system, as well as how the ClimaCool units ideally capitalize on this type of energy.”

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