Due to the heat storage capacity of soil, latent and sensible heat from the airflow accumulates
in the ground around the pipes, gradually reducing the cooling capacity. To restore the original ground temperature, cold ambient air is injected through the pipe system during the night. Ideally, the heat injection is balanced by an equal amount of cooling. The mean soil temperature will nevertheless be higher than the undisturbed soil temperature during the irrigation season. During fallow periods, the soil temperature is lowered by natural means or by night air cooling.