Experimental Analysis of Soil Recovery and Heat Interactions with Ground in Slinky Connected Split Air-Conditioning System

Abstract

In the present research work experimental analysis of soil recovery and heat interaction of slinky ground heat exchanger connected with a split air-conditioning system has been reported. For the analysis a 1.5-ton cooling capacity split air-conditioning system coupled with a slinky type of heat exchanger was deployed at IIT Roorkee campus, India. All the experiments were carried in peak summer conditions during space cooling mode operation. Initially, the heat interaction through the GHX to the ground is analysed throughout the experiments, later once the experiments are over, the ground temperature is monitored to estimate the soil recovery period by circulating water in the GHX. For the present location, several experimental trials were carried out and recorded the soil recovery period for different operating hours. A regression analysis is performed to stablish a correlation between the soil recovery period and the operating hours. The rate of heat rejection to the ground varies from 5 to 8 kW on a typical day in peak summer condition. The ratio of soil recovery and the operating hours is observed to be more than 1 when ground coupled split air-conditioning system is operated from 5 to 12 hours in daytime. Operating the split air-conditioning system for more than 12 hours shows a lesser recovery time as compared to the operating hours due to partial recovery of the ground during lesser cooling load during the nighttime.