Page 68 - GRIHA Manual Volume III - Introduction to National Rating System
P. 68
Building and system design optimization 61
depends upon the quantity of air being cooled. The length of the pipe varies from 50 m–100 m. This
is the part, which is responsible for heat transfer or cooling of the air. At the end of EAT, usually a fan
room is provided. A blower fan in the fan room draws the air from the intake column and supplies it
to the designated spaces through supply ducts or pipes. The earth air tunnel can provide air to the
o
o
spaces at a temperature of 28 C–30 C in summer and 18 C–20 C in winter.
o
o
Geothermal heating and cooling
The geothermal heat pumps (GHP) work on a principle similar to earth air tunnels. The GHP utilize
the stable temperatures through the use of heat exchangers. This contact temperature can be used
to provide heating, cooling, and hot water for homes and commercial buildings.
Geothermal heat pumps can be classified into closed-loop system and open-loop system. The
loops can be installed in three ways—vertically, horizontally, and in a pond or lake, depending upon
the availability of land area and soil/rock type at the chosen site.
Open-loop system: Open-loop systems pump groundwater from an aquifer through a well,
and send it through the heat pump’s heat exchanger. The water is discharged to the same
aquifer via another well located at a distance from the first. Since the temperature of groundwater
is nearly constant throughout the year, open loops are a popular option in areas where they
are permitted.
Closed-loop system: Closed-loop systems are more economical, efficient, and reliable, as
compared to open loop systems. It is also the most commonly used system. In this water is
circulated through a continuous buried pipe. The closed-loop system is safer because water in
the loop prevents contamination to the external environment. The length of loop piping varies
depending on ground temperature, thermal conductivity of the ground, soil moisture, and system
design. Closed loop system can be classified as horizontal closed-loop, vertical closed-loop, and
pond closed-loop.
Figure 7 Horizontal closed-loop system
depends upon the quantity of air being cooled. The length of the pipe varies from 50 m–100 m. This
is the part, which is responsible for heat transfer or cooling of the air. At the end of EAT, usually a fan
room is provided. A blower fan in the fan room draws the air from the intake column and supplies it
to the designated spaces through supply ducts or pipes. The earth air tunnel can provide air to the
o
o
spaces at a temperature of 28 C–30 C in summer and 18 C–20 C in winter.
o
o
Geothermal heating and cooling
The geothermal heat pumps (GHP) work on a principle similar to earth air tunnels. The GHP utilize
the stable temperatures through the use of heat exchangers. This contact temperature can be used
to provide heating, cooling, and hot water for homes and commercial buildings.
Geothermal heat pumps can be classified into closed-loop system and open-loop system. The
loops can be installed in three ways—vertically, horizontally, and in a pond or lake, depending upon
the availability of land area and soil/rock type at the chosen site.
Open-loop system: Open-loop systems pump groundwater from an aquifer through a well,
and send it through the heat pump’s heat exchanger. The water is discharged to the same
aquifer via another well located at a distance from the first. Since the temperature of groundwater
is nearly constant throughout the year, open loops are a popular option in areas where they
are permitted.
Closed-loop system: Closed-loop systems are more economical, efficient, and reliable, as
compared to open loop systems. It is also the most commonly used system. In this water is
circulated through a continuous buried pipe. The closed-loop system is safer because water in
the loop prevents contamination to the external environment. The length of loop piping varies
depending on ground temperature, thermal conductivity of the ground, soil moisture, and system
design. Closed loop system can be classified as horizontal closed-loop, vertical closed-loop, and
pond closed-loop.
Figure 7 Horizontal closed-loop system
