Corbin Utilities Office and Warehouse Renovation

  • Corbin City Utilities Commission Offices, Corbin, KY
     Corbin City Utilities Commission Offices, Corbin, KY
  • Corbin City Utilities Commission Offices, Corbin, KY
     Corbin City Utilities Commission Offices, Corbin, KY
  • Corbin City Utilities Commission Offices, Corbin, KY
     Corbin City Utilities Commission Offices, Corbin, KY

GRW provided design and construction administration services for the renovation of an existing automobile dealership into a new office, maintenance garage, and storage facility for City Utilities Commission of Corbin, KY.  The project included the following energy efficient items:

Hydronic Geothermal System

  • A 10-bore geothermal wellfield was installed to provide a constant source of heating and cooling to hydronic fluid required for building HVAC needs.
  • The geothermal wellfield is connected to 15 water-source heat pumps.  Each heat pump provides heating or cooling to a room or series of rooms (i.e., a “zone”), and each zone is able to be independently heated or cooled as space requirements change.
  • The geothermal system also conditions fresh air at a make-up air unit which provides the code-required percentage of fresh air to each zone during occupied periods of building operation.
  • The geothermal HVAC system eliminates the equipment and costs associated with mechanically heating or cooling the hydronic fluid via traditional boiler and cooling tower systems.
  • Additional energy efficiency and cost savings was achieved by installing variable-speed pumps on the hydronic (geothermal) piping serving the interior heat pump units.  Flow is varied based on demand, reducing the flow (and energy requirements) during part-load conditions. 

Direct Digital Control (Ddc) System

  • A central computer controls the building HVAC system, allowing the users to establish periods of occupied and unoccupied operation and reduce building loads during unoccupied periods.


  • High-efficiency plumbing fixtures were utilized throughout the design.  These identical fixtures have been used to achieve LEED (v2.2) calculated water savings of over 30% (when compared to standard fixtures) on other GRW projects.
  • High –efficiency sinks are equipped with low-flow aerators (0.5 gallons per minute) and proximity sensors to flow only when necessary.
  • High-efficiency shower heads are equipped to flow at 1.5 gpm.
  • High-efficiency water closets have a flow rate of 1.28 gallons per flush.
  • High-efficiency urinals have a flow rate of 1/8 gallon per flush.

High Efficiency Lighting

  • High efficiency fluorescent lighting was used throughout the interior of the building and perimeter exterior lighting. Linear fluorescent T-5 lamps were used.

High Efficiency Lighting Control

All interior and exterior lighting is controlled by direct digital control (DDC). The DDC was programmed to turn interior lighting circuits on at scheduled work time. The exterior lighting was programmed to be on during darkness. The office portion of the building has dual level local switching for control by occupants. The operations portion of the building also has local dual level switching by occupants. Lighting is only on when needed and only the amount of light required is used. Lighting is programmed to be off during periods of non-occupancy. Override switches are available to turn on lighting when required during non-scheduled working hours.

According to Ron Herd, General Manager, City Utilities Commission, "The geothermal applications have made a huge difference in cutting our energy costs. The board's vision was not only to make it a comfortable, inviting and professional environment for our customers, but also for our valued employees. It's a win-win for the community."