Experimental Investigation of Earth Tube Heat Exchanger (ETHE) for Controlled Ventilation in Erbil

The achievable performances of energy by using an earth tube heat exchanger for controlling an air-conditioning for building is evaluated for nine months in a whole year. It is a well notorious fact that; if we get below the surface of the earth a few meters, the temperature tends to be constant and around 7- 22°C, depending on latitude and soil properties. So, it could alter its energy, and move it into the house where it can raise or lower the temperature. Earth Tube Heat Exchanger (ETHE) is used to cool down the zone in the hot days and to heat the zone in cold days. The temperatures of Underground can be significantly important for energy balance for the house thermal comfort. A single L-shape passes, a closed loop Earth Tube Heat Exchanger (ETHE) is installed in Erbil (36°N, 44°E), to investigate its performance for heating and cooling conditions. ETHE is made of 31 m long and 10 cm nominal diameter and 3 mm wall thickness tube. ETHE is buried 3 m below the elevation of the earth surface. Outside air is pumped through it by blowers with a flow rate of 159 m
³
/hr. Air temperature is measured at the inlet and outlet of the pipe through thermostats fixed inside the pipe. ETHE is able to cool the zone easily for ventilation from 35°C to 25°C in the hot days, hourly kept the zone between (20–23) °C. The result shows the average temperature of the soil is 21.88 °C during a year and the COP of the ETHE system is 5.13 in the winter seasons.