Technical and environmental evaluation of 24-hour heating and cooling storage system for1 year in non-residential buildings using underground pipes

Considering the demands on constructing high energy performance buildings, technical solution is needed to be used for decreasing and improving the energy consumption. One of this solutions is underground energy storage that is considered based on short-term or long-term usage. In this study, a hospital in Tehran city, as a high energy performance building, was investigated. Fluid and heat transfer calculation for heat and cold storage in the building was simulated using MATLAB software for underground pipes. Also heating and cooling loads of the building was calculated by HAP4.5 software and the results were imported to MATLAB software. Then the volume and quality of the 24-hour and seasonal systems and reduction of carbon dioxide emissions were compared. Heating storage system does not reduce the heating and cooling demand of the building, but application of an underground storage can decrease the amount of bought energy and the subsequent environmental damage. The results showed that application of a 24-hour storage system with 15 lines of steel pipes with the length of 600 m and nominal diameter of 3 inches placed in a ground depth of 3 m, yields 67% heating load and 34% cooling load and reduce CO2 emissions by 127 tons per year.  However, application of a 1-year storage system with 45 lines of steel pipes with the same specification placed in a ground depth of 5 m, yields 98% heating load and 39.5% cooling load and reduces CO2 emissions by 169.2 tons per year.