Seminar 63: LIVESTREAM: Effective Cold Climate Decarbonization Applications with Ground Source Heat Pumps
Wednesday, June 28 9:45 AM – 10:45 AM EDT
Chair: Lisa Meline, P. E.
Session Type: Seminar Program Level: Intermediate Program Track: HVAC&R Systems and Equipment Meeting Format: Livestream
Summary:
Ground Source Heat Pumps (GSHPs) are well suited to provide high efficiencies for effective decarbonization in cold climates eliminating fossil fuel use for space and water heating. A GSHP case study is highlighted of a four-story mixed use apartment complex, served by a vertical ground heat exchanger and a 248-kW solar array. A second case study features a seasonal solar thermal energy storage system installed to balance a vertical loop system. A third presentation demonstrates methods for determining GSHP CO2 savings compared to fossil fuel furnaces in two states with different electric utility C02/kWh generation rates.
Seminar 63: Presentation 1: Applying Ground Source Heat Pumps to Decarbonize a New Multi-Family Building in the Hudson Valley
Wednesday, June 28 9:45 AM – 10:05 AM EDT
Applying Ground Source Heat Pumps to Decarbonize a New Multi-Family Building in the Hudson Valley
Presenting Author: Hugh Henderson, P.E., Owahgena Consulting, Cazenovia, NY, USA
A new 63,300 sq. ft. building with 46 apartments and 6 retail spaces uses a ground loop to meet its space conditioning needs as well as provide water heating. The high efficiency building envelope reduces space heating loads so that only small water source heat pumps were required in each space. The ground loop heat exchanger sized for space cooling loads could also easily meet the water heating loads – eliminating the need to keep a fossil fuel boiler for DHW loads. Detailed field monitoring in this building confirmed the expected benefits and fossil fuel reductions.
Seminar 63: Presentation 2: Seasonal Solar Thermal Energy Storage for Balancing Cold Climate GSHP Systems
Wednesday, June 28 10:05 AM – 10:25 AM EDT
Seasonal Solar Thermal Energy Storage for Balancing Cold Climate GSHP Systems
Presenting Author: Daniel Booy, P.Eng., Altum Engineering Ltd., Courtenay, BC, Canada
This case study examines the thermal response of a frozen GHX when a low-cost HDPE solar collector array was used to reheat the ground. The system was installed in 2018 after the minimum heating season temperature of the GHX became too low, which rendered the GSHP system inoperable. The control system that was used for the integration of the solar panels and the GHX has remote connectivity and data logging capabilities. The monitoring and data acquisition enabled optimization of the control algorithms to maximize the reheating and ensure that the pump energy use was optimized.
Seminar 13: Presentation 2: Resilient Cooling through Geothermal District Energy Systems
Sunday, June 25 11:20 AM – 11:40 AM EDT
Resilient Cooling through Geothermal District Energy Systems
Presenting Author: Michael Wetter, Ph.D., Lawrence Berkeley Lab, Berkeley, CA, USA
Geothermal district energy systems are well suited to decarbonize heating and to provide efficient cooling. However, little is understood about how they should be designed, sized and operated to provide compressor-less cooling during heat waves. We show how Modelica simulations of geothermal, HVAC and controls, coupled to EnergyPlus envelope via Spawn, can be used to design and assess the performance of such systems for an office district in the Chicago climate. We show that indoor air conditions are maintained in a tolerable range for most rooms, while electricity consumption is reduced by a factor of two.
