Presentation on theme: "Just How Bad Could It Be….. Presented by: Phil Rawlings, CGD Director Of Geothermal Services TRC Energy Services - Geothermal."— Presentation transcript:
Just How Bad Could It Be….. Presented by: Phil Rawlings, CGD Director Of Geothermal Services TRC Energy Services - Geothermal
Project Reality Check #1 This project is real – this is not a compilation of extreme example slides from all over the country – this is one existing family housing project. The following slides are a real geothermal application on a military facility. Fortunately, it is in the process of being corrected as we speak.
Original Design Criteria The original Design Criteria was: The original Design Criteria was: Outdoor Conditions: (ASHRAE 1%/99%) Outdoor Conditions: (ASHRAE 1%/99%) Cooling: 92 ° F Dry Bulb/78 ° F Wet Bulb Heating: 27 ° F Indoor Conditions: Indoor Conditions: Cooling Thermostat Set Point: 72° F Heating Thermostat Set Point: 70 ° F
Project Reality Check #2 This is Military Family Housing. Thermostats can be set at any temperature, and occupants were not paying the utilities. Example actual thermostat worst case set points were mid 60s (66° F observed) in cooling, and 78-80 in heating. Since the occupants do not pay the bills, there is no incentive to conserve energy or follow set point mandates
Design Problem #1 Considering known thermostat abuses in military family housing, the following design approach is very questionable: “The GCHPs were selected to maximize their run-time to assist in dehumidification in the cooling season and to facilitate the operation of the desuperheater to provide the maximum of domestic hot water heating.” OR – They were undersized at design conditions
Design Problem #2 Heating Requirements: Evidently heating requirements were not considered as the system was designed – during/after the first winter all geothermal heat pumps were retrofitted with 5 kW strip heat units to solve almost universal inadequate heat complaints.
Design Problem #3 The vertical ground heat exchangers were designed around the calculated capacity of the dwelling at design conditions, not the capacity of the GCHP installed. OR – a 19,000 BTU loop design with a 24,000 BTU nominal capacity the GCHP applied will overwhelm the loop and run away – EWTs of well above 110° F have been observed.
The Ongoing Corrections Add insulation to attics Add insulation to attics Correct ductwork sizing as needed Correct ductwork sizing as needed Aeroseal ductwork Aeroseal ductwork Test and seal envelope Test and seal envelope Upgrade GCHP sizing as needed Upgrade GCHP sizing as needed Install additional vertical ground heat exchanger as needed Install additional vertical ground heat exchanger as needed Corrected As-Builts Corrected As-Builts
Original Installation Issues that significantly impaired performance and contributed to occupant dissatisfaction
As-Built Drawings….. The Vast Majority Are WRONG!!!!