29 Influence of Thermal Conductivity and Subsurface Temperature …
443
Here, regional characteristics refer to meteorological conditions, thermal conductivity and subsurface temperature. Given that the size of ground heat exchanger
affects the environmental load during the manufacturing and installation stages, it is
essential to conduct the LCA based on the optimal design of ground heat exchanger
in order to evaluate the life cycle environmental load properly.
Generally, rich groundwater flow enhances thermal conductivity (Shrestha et al.
2015), and GSHP’s efficiency is highly affected by thermal conductivity and heat
source temperature, i.e., subsurface temperature (Yasukawa et al. 2009; Safa et al.
2015). Therefore, clarifying the influence of changes in thermal conductivity and
subsurface temperature on the life-cycle environmental load are important to verify
an environmental performance of GSHP in Bangkok under the various groundwater
flow and subsurface temperature conditions.
29.2 Objective
The objectives of this research are to conduct life-cycle inventory and sensitivity
analysis for the installation of a GSHP system with an optimally-designed ground heat
exchanger in a commercial building, such as a super market, in Bangkok, Thailand.
The goals of life-cycle inventory analysis are to calculate the life-cycle CO 2 , NO X ,
and SO 2 (LC–CO 2 , LC–NO X , and LC–SO 2 , respectively) emissions. The parameters
of sensitivity analysis are the thermal conductivity and subsurface temperature.
29.3 Methodology
29.3.1 Simulation of Cooling Load
“The Best Program” (Hasegawa et al. 2017) was used to design an architecture
model of a commercial building and calculate the hourly annual cooling load. The
architecture model is a square of 40 × 40 m with two floors at a floor-to-floor height
of 7 m. Thus, the total floor area of the architecture model was 3200 m
2 . Each floor
has a perimeter zone and an interior zone. The perimeter zone was an area up to 5 m
inside from the outer wall, and the other area were treated as interior zone.
The annual cooling load was calculated by inputting the architecture model, air
conditioner operation schedule, and “EnergyPlus” weather data in Bangkok (EPW
weather data) (Crawley et al. 2000) into “The Best Program”. The operation schedule
was set at 365 days per year and 8:30–22:30 (14 h per day) in accordance with typical
supermarkets in Thailand. Moreover, the room temperature and relative humidity
were set at 26 °C and 50%, respectively.
Table 29.1 shows the specifications of architecture model and cooling load
simulation results.
443
Here, regional characteristics refer to meteorological conditions, thermal conductivity and subsurface temperature. Given that the size of ground heat exchanger
affects the environmental load during the manufacturing and installation stages, it is
essential to conduct the LCA based on the optimal design of ground heat exchanger
in order to evaluate the life cycle environmental load properly.
Generally, rich groundwater flow enhances thermal conductivity (Shrestha et al.
2015), and GSHP’s efficiency is highly affected by thermal conductivity and heat
source temperature, i.e., subsurface temperature (Yasukawa et al. 2009; Safa et al.
2015). Therefore, clarifying the influence of changes in thermal conductivity and
subsurface temperature on the life-cycle environmental load are important to verify
an environmental performance of GSHP in Bangkok under the various groundwater
flow and subsurface temperature conditions.
29.2 Objective
The objectives of this research are to conduct life-cycle inventory and sensitivity
analysis for the installation of a GSHP system with an optimally-designed ground heat
exchanger in a commercial building, such as a super market, in Bangkok, Thailand.
The goals of life-cycle inventory analysis are to calculate the life-cycle CO 2 , NO X ,
and SO 2 (LC–CO 2 , LC–NO X , and LC–SO 2 , respectively) emissions. The parameters
of sensitivity analysis are the thermal conductivity and subsurface temperature.
29.3 Methodology
29.3.1 Simulation of Cooling Load
“The Best Program” (Hasegawa et al. 2017) was used to design an architecture
model of a commercial building and calculate the hourly annual cooling load. The
architecture model is a square of 40 × 40 m with two floors at a floor-to-floor height
of 7 m. Thus, the total floor area of the architecture model was 3200 m
2 . Each floor
has a perimeter zone and an interior zone. The perimeter zone was an area up to 5 m
inside from the outer wall, and the other area were treated as interior zone.
The annual cooling load was calculated by inputting the architecture model, air
conditioner operation schedule, and “EnergyPlus” weather data in Bangkok (EPW
weather data) (Crawley et al. 2000) into “The Best Program”. The operation schedule
was set at 365 days per year and 8:30–22:30 (14 h per day) in accordance with typical
supermarkets in Thailand. Moreover, the room temperature and relative humidity
were set at 26 °C and 50%, respectively.
Table 29.1 shows the specifications of architecture model and cooling load
simulation results.