Climate change stabilization requires an unprecedented effort to change our current approach to energy production and consumption. While rising energy prices are drawing increased attention to reducing energy demand, heightened concern about the environmental consequences of fuel choice requires that this demand be met at lower emission levels. In Canada, the realization of commitments to our GHG emission goals entails reducing residential energy use - a sector responsible for close to 20 percent of end-use energy consumption. This study focuses on the energy demand and emission levels of space and water heating, since these two components comprise 76 percent of residential energy demand. Ground source heat pumps (GSHPs) are a technology that provides heating at 25 to 30 percent of the energy consumed by even the most efficient conventional alternatives. GSHPs have been identified as the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available. However, their drawbacks have been high capital costs, and uncertainty about whether the electric power used by heat pumps has higher system-wide emissions. This thesis delineates how adoption of GSHPs in the residential sector can help align Canada’s technology choices with commitments made to the Kyoto Protocol. The manuscripts delineate conditions under which GSHP systems achieve the largest net emission reductions relative natural gas, heating oil, and electric heat counterparts. Electricity generation methods and emissions embodied in inter-provincial and international electricity trade are shown to significantly affect the emission savings achievable through GSHP. The thesis quantifies how relative fuel prices influence annual operating savings that determine how rapidly the technology can achieve payback. This analysis reveals GSHPs to hold significant potential for substantial GHG reductions at a cost savings relative to conventional alternatives; the time horizons for payback are as short as nine years for average-sized homes, and significantly shorter for larger homes. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

Ground source cooling is commonly used for cooling of electronics in protected sites. Sometimes the boreholes are combined with free cooling from the air using a dry cooler to reduce the amount and length of the boreholes, which is the biggest part of the costs. The dry cooler can have two different running modes. In unloading mode the dry cooler is started at a certain temperature and the fans are slowed down at low temperatures so that the cooling power never exceeds the cooling demand. The extracted cooling is used to unload the boreholes. In recharging mode the dry cooler is started at a certain temperature and is operating at full capacity below this temperature. The excess cooling that is extracted in this mode is used to recharge the boreholes. The numerical simulation tool COMSOL Multiphysics was used to evaluate the borehole performance. The software can simulate tilted boreholes with good accuracy and makes it possible to adjust the geometry in any desired way. In this thesis, the performance of a 100 kW ground source cooling system is evaluated for a number of cases both with and without dry coolers in different running modes and sizes. The best solution in respect to life cycle cost, technical feasibility and environmental impact is chosen to be an unloading case with a dry cooler with 100 kW capacity at 8 °C. Using only boreholes gives less carbon dioxide emissions but much higher costs.

The expansion of the use of geothermal heat pumps makes the study of their performances a keystone in their development. Several parameters are crucial to design properly a geothermal heat pump. Comparing the theoretical characteristics of a system with the actual ones one the field is part of its understanding.  This Master thesis gives a closer look for determining from filed data two central parameters, the borehole thermal  resistance  and  the  ground  thermal  conductivity,  using  a  newly  developed  technique  called Distributed Thermal Response Testing (DTRT). These calculations are applied to a U-pipe heat exchanger installed  in  a  private  household.  From  these  two  parameters,  it  is  possible  to  estimate  the  thermal conductivity of the filling material inside the borehole and thus estimate its influence on the performances of  the  system.  Three  grouting  material  are  studied  here  and  theoretical  values  are  compared  with experimental value in order to try to get a picture of the inside of the borehole.  This  thesis  provides  a  picture  of  the  actual  thermal  parameters  of  the  studied  borehole,  which  clearly reveals the influence of the grouting material in each layer. It is also noticed that the laboratory value of the grout thermal conductivities varies when comparing with theoretical values or manufacturer data. The lack of understanding of the actual drying state of the grouts inside the borehole may by one reason why.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Ground source heat pumps (GSHPs) offer an efficient method for cooling and heating buildings, reducing energy usage and operating cost. In hot, arid regions such as Texas and the southwest United States, building load imbalance towards cooling causes design and performance challenges to GSHP systems in residential and commercial building applications. An integrated building load and GSHP model is developed in this thesis to test approaches to reduce GSHP cost, to properly size ground heat exchanger (GHEX) installations and to offer methods to improve GSHP performance in commercial buildings. The integrated model is comprised of a three-story office building, heat pumps, air handling system and a GHEX. These component models were integrated in the Matlab® Simulink® modeling environment, which allows for easy model modification and expansion. The building-load model was developed in HAMBASE, which simulates the thermal and hygric response of each zone in the building to external weather and internal loads. The building-load model was validated using the ASHRAE 140-2007 Standard Method of Test and with results from EnergyPlus. The heat pump model was developed as a performance map, based on data commonly provided by heat pump manufacturers. This approach allows for easy expansion of the number and type of heat pump models supported. The GHEX model was developed at Oklahoma State University and is based on Eskilson’s g-function model of vertical borehole operation. The GHEX model accurately represents the interaction between boreholes and the ground temperature response over short and long time-intervals. The GHEX model uses GLHEPRO files for parameter inputs. Long time-interval simulations of the integrated model are provided to assess the sensitivity of the GSHP system to various model parameters. These studies show that: small changes in the total GHEX length reduce system cost with minimal impact on performance; increased borehole spacing improves system performance with no additional cost; supplemental heat rejection reduces installation costs and improves system performance; industry-recommended design cutoff temperatures properly size the GHEX system; and, while cooling is the greatest contributor to operating cost in the southwest and southcentral United States, heating is the limiting design case for GHEX sizing. / text

Mr Wayne Tobeck, Director of Southrim Group (SRG), sponsored this 2013 MEM Project titled; A Technical and Economic Feasibility Study for the Integration of GSHP Technology in the Christchurch Rebuild. Following the recent Christchurch earthquakes, a significant amount of land has become too unstable to support traditional building foundations. This creates an opportunity to implement new and unique foundation designs previously unconsidered due to high costs compared to traditional methods. One such design proposes that an Injection Micro-Piling technique could be used. This can also be coupled with HVAC technology to create a Ground Source Heat Pump (GSHP) arrangement in both new buildings and as retrofits for building requiring foundation repair. The purpose of this study was to complete a feasibility study on the merits of SRG pursuing this proposed product. A significant market for such a product was found to exist, while the product was also found to be technically and legally feasible. However, the proposed product was found to not be economically feasible with respect to Air Source Heat Pumps due to the significantly higher capital and installation costs required. Further analysis suggests GSHPs may become more economically attractive in operating temperatures lower than -9oC, though the existence of markets with this climate in NZ has not been studied. It is therefore suggested that SRG do not proceed with plans to develop a GSHP coupled foundation solution for the Christchurch rebuild.

Master of Science / Department of Architectural Engineering / Fred Hasler / Ground-coupled heat pump (GCHP) systems use the ground as a heat source or sink that absorbs heat from or rejects heat to the soil, respectively; this is referred to as the geothermal heat exchanger. Apart from the geothermal heat exchanger, there are two other main system components that make up a GCHP system: heat pumps and circulation pumps. This report studies four GCHP pumping systems and makes comparisons between the four using life-cycle cost analyses for six building models. The goal for this analysis was to discover commonalities between the models in order to provide designers insight into which pumping system is the most cost effective. The analysis was performed by first creating energy models to obtain system and zone load information, as well as system part-load data and geothermal heat exchanger performance. From the zone load information, heat pump selections were then performed to indicate the worst case piping path that is required for pump head calculations. Piping layouts were created to establish pipe lengths for the pump head calculations as well. Other piping components such as valves and fittings and the air separator pressure drops were also calculated. Once the pump head calculations were complete for each system, pump schedules were created. From there initial unit and installation costs were determined for each pump, as well as their replacement costs. The part-load data from the energy models were then used to obtain annual pump energy consumption and pump utility cost. Finally, assumptions were made to establish regular and preventative maintenance requirements for each pumping system. Initial and replacement unit costs, annual utility cost and regular and preventative maintenance costs were the components used in the life-cycle cost analysis. Each of these components was converted to 30-year projected costs and added to create a total life-cycle cost for each pumping system. Comparisons were then made and the results showed that a primary pumping system with VFD control and 100% redundancy was the most cost effective system. However, there are other considerations such as controllability, flexibility and availability that might persuade designers to choose one of the other alternate solutions.

In this research paper, review of world geothermal energy production and their capacity is shown. Here, a research is conducted to know the potential and possibility of geothermal energy in India. All the geothermal province with their geographical locations are shown and a brief calculation is conducted in order to show the potential of the particular province. As India is having the low temperature geothermal fields, binary geothermal plants are used for this analysis and results are calculated by using R134a as a working fluid at different temperatures. The results are sufficient to prove the potential of geothermal energy in India.  Importance of Ground Source Heat Pump (GSHP) and power savings by its contribution over traditional heating and cooling methods is shown statistically. 9 different states of India are divided by their climatic condition, severe winter and moderate winter to calculate the heat demand in those states. Also, for the cold demands these states are considered to be same as per the climatic situation in summer. Then, comparison is done between GSHP and the traditional heating and cooling systems. The result shows the drastic power saving by using GSHP for space heating as well as cooling, over electric heater and air conditioner respectively.

<p>2008-05-26</p><p>Bedrock heat as an energy source</p><p>The sun has warmed up the bedrock and this heat can be used for warming up houses. Approximately 100 – 200 meters down in the bedrock the temperature of the heat is stable. This is a source of energy that can be used by installing a heat pump system. The ground source heat pumps are low maintenance and can last for many years. There is also a pollution risk for the groundwater and therefore the wells in the area. Before the ground source heat pump can be installed the municipality need to give permission, according to the environmental code. To install the system without permission is a crime against the environmental code. A requirement when applying for permission to install the heat pump system is to get the neighbours to agree with the place for the bore hole. The neighbour can appeal against the environmental and health authorities’ decision to give permission to install the ground source heat pump system. However there needs to be more research done regarding the environmental effects that may occur in the future, if the ground source heatpump system continues to increase as rapidly as today.</p>

2008-05-26 Bedrock heat as an energy source The sun has warmed up the bedrock and this heat can be used for warming up houses. Approximately 100 – 200 meters down in the bedrock the temperature of the heat is stable. This is a source of energy that can be used by installing a heat pump system. The ground source heat pumps are low maintenance and can last for many years. There is also a pollution risk for the groundwater and therefore the wells in the area. Before the ground source heat pump can be installed the municipality need to give permission, according to the environmental code. To install the system without permission is a crime against the environmental code. A requirement when applying for permission to install the heat pump system is to get the neighbours to agree with the place for the bore hole. The neighbour can appeal against the environmental and health authorities’ decision to give permission to install the ground source heat pump system. However there needs to be more research done regarding the environmental effects that may occur in the future, if the ground source heatpump system continues to increase as rapidly as today.