The article “Analysis of Ground Source Heat Pumps with Horizontal Ground Heat Exchangers for Northern Japan”¯ by V. R.Tarnawski, W. H.Leong etc considers the potential application of a ground source heat pump system (GSHP) with a horizontal ground heat exchangers (GHE) for the living space 200m2 of a residential house located in Japan in heating and cooling. Despite the electricity rate is estimated as relatively high, the GSHP system appears to be more optimal for space heating than an oil furnace and electric resistance heating. In terms of uncertainty in the economic growth of the country and maintaining its international competitiveness inevitably results in searching an alternative way of heating that offers saving of the non-renewable energy resources and keeping the surroundings as intact as possible, lowering the influence on thermal degradation of the ground environment and reducing the issues on unstable geology. So, application of horizontal loops is counted to be particularly feasible in the rural areas of Japan as well as in the mainland, as it presupposes lowering the cost of heating and cooling and decrease of operating efficiency (COP>3).
The article “Geothermal Heat Pumps: An Increasingly Successful Technology”¯ by Gerald W. Huttrer concerns outlining the benefits of geothermal heat pump systems and comparing open and closed loop configurations that are vertical, horizontal, surface water closed loops and standing column well open loops. GHP utilizing the earth or water bodies function efficiently and provide maximum heat pump output. GHPS are presently feasible as they lower operating costs, namely reduce energy bills using fossil energy recourses, do not have noisy emissions-prone outdoor unit unlike other HVAC systems, provide greater reliability and comfort. They also have such utility benefits as flatter power load profile and customer satisfaction stability. Since 1980s the number of GHP systems increased dramatically the reason lying in the simplicity and their energy, economic efficiency. Technology awareness and education, financial support to end users, first cost reduction are the main activities applied to in GHP industry.
The article “The Analysis on a Potential of Saving Energy and Environmental Benefits on Heat Pump in Geothermal Heating”¯ by Wanyue Wang and Yunshan Han considers the potential of saving energy and reducing the environmental pollution due to the application of geothermal heating pump systems and presents geothermal heating optimization proposal. Taking into account the Taiyuan’s geothermal space peculiarities and the gradual worsening of heating effect in the area the scholars made a comprehensive analysis of thermal efficiency, first investment, operating cost, equipment cost, environmental consequences and other factors in order to prove the potential of heat pump systems. They analyzed the energy-saving effect and claimed that HPS may be also used for air conditioning and domestic hot water and compared with coal burning boilers these systems reduce energy demand and contamination of the environment canceling or decreasing emissions. Hence, HP technology is regarded as feasible as its COP exceeds 2.
The article “Geothermal Heat Pumps”¯ by Gary Phetteplace presents an overview of the application of geothermal heat pumps on both residential and commercial scale. The scholar approves of their sustainability as they reclaim and recycle thermal energy from the earth. He thoroughly analyses the geothermal heat pump types and their advantages, claiming, however, that he does not expect rapid development of present-day configurations of the systems in residential sector, though is can be forecasted in the commercial sector where GSHP systems become more competitive than their conventional prototypes. He distinguishes the main types of GSHP systems that are: ground-coupled heat pumps (GCHP), ground water heat pumps (GWHP) and surface water heat pumps (SWHP).
GCHP do not require drilling equipment and have greater potential for heat exchange with ground water and high adaptability. GWHP systems being the oldest form of GSHP have the lowest cost in most cases but their application is limited by the ground water access. SWHP systems unlike GWHP that extract water from the ground, extract and discharge heat to surface water bodies. Phetteplace admits that though the infrastructure remains underdeveloped in some areas, expanded application of geothermal heat pumps is definitely feasible in the US.