In 2023, the Rochester-based Genesee Co-op Federal Credit union decided they wanted to convert their historic building to geothermal. In 2022, the building and neighboring lot was purchased, with the intention that the Co-op would expand and solidify it’s roots in the community. We were honored to be considered as a part of the project when they approached us about exploring renewable energy options.
Step 1: Geothermal Loopfield and Installation Planning on a Brownfield Site
With this project, the plan was to utilize a neighboring lot recently purchased by the Co-op for the vertical loopfield. This space was formerly a gas station and autobody shop, meaning, it was previously exposed to chemicals and may still contain some within the soil. With this, it carried the status of being a former Brownfield.
What is a brownfield? The EPA defines a brownfield as “…a property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.”
With the site being considered a former brownfield, special care was taken to ensure that the earth being disturbed was not exposing any toxic elements to the jobsite and community. To ensure of this, we followed the NYS DEC Workplan for the specific site and partnered with LaBella Associates to meet its requirements. LaBella staffs a team of geologists, and environmental remediation specialists to ensure the DEC requirements for the property had been met.
We made sure to make community members, and bank customers aware of what was going on so they could follow the project along as well!
Step 2: Drilling the Geothermal Loopfield
The Genesee Co-op Federal Credit Union had planned for 7 (250′) vertical wells to be drilled on their .46 acre lot to support their HVAC system.
Special Provisions Taken on this Brownfield Site During the Loopfield Installation:
- All groundwater captured and contained, with testing prior to discharge.
- Ongoing Community Air Monitoring Plan (C.A.M.P) at all times when we were drilling to ensure no VOCs were brought to the surface.
- Daily work progress reports sent to the DEC for their records
- Decontamination of tools used within the brownfield site
The loopfield installation went as planned, and at completion, we were ready to begin the lateral tie in!
Step 3: Geothermal Lateral Tie In
The lateral tie in portion of the project is required to connect the loopfield to the manifold inside of the building! During this process, all of the well heads are connected to HDPE piping that is connected to the building. Through this pipe, water and antifreeze will continually circulate in a closed loop, through the geothermal heat pump equipment. A closed loop means that the water we “charge” the piping system with will never leave that piping system or enter the earth directly! It will remain within the piping system.
After all of the pipes meet at the entrance to the building, they are routed to the interior manifold and pump system. This system distributes the water to each geothermal heat pump unit within the building to allow for heating and cooling operations to take place.
Step 4: Geothermal Unit Installation
Within the space, 6 geothermal units support the heating and cooling needs of the building. These units are placed in various spaces, and are of various sizes required by the individual spaces they are supporting.
Step 5: Loopfield Flushing, Filling and Charging!
Once the geothermal units have been installed, and the system is just about ready to be operationalized, we do what we call a Flush and Fill. This is required so that all debris that may have entered the loopfield system during installation (think small rocks, dirt, etc.) is purged to ensure the highest quality of water is being circulated through the loopfield at all times. Water with poor quality, and debris, can cause strain on geothermal units and contribute to poor performance and loss of integrity over time.
For the flush and fill, we utilize our purpose-built flush trailer that allows for pumping at up to 480gpm, hydrostatic testing, and injection of antifreeze fluids into the loop.
For this project, CoreChem GlycoChill Inhibited Propylene Glycol was used to charge the loopfield. This heat transfer fluid acts as an antifreeze, and prevents the loopfield from poor operations when its fluid temperature drops.
Step 6: Project Completion
Once the loopfield has been flushed, filled and charged, and all geothermal units have been installed, we can operationalize the system.
Starting in September of 202,4, the Genesee Co-op Federal Credit Union successfully began heating and cooling using the natural energy sourced from underground.
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