Evaluation of Basement's Thermal Performance Against Thermal Comfort Model at Hot-arid Climates, Case Study (Egypt)

Abstract

Reaching thermal comfort levels in hot-arid climates is becoming more difficult nowadays without the use of high energy consuming mechanical systems. Therefore, the need to use effective passive energy design techniques such as earth-sheltered buildings is becoming greater. This paper combines researches that uses monitoring and simulations in order to evaluate basements’ thermal performance that reached thermal comfort levels without active air-conditioning systems, despite the harsh climate conditions. The case study was conducted in Al-Minya city, Egypt, which is known for its high diurnal range. The study calibrated a non-conditioned basement simulation model versus the monitored data to simulate its thermal performance. The greatest challenge was to calculate the ground temperature. To do this successfully, we used an iterative approach between packages of the basement preprocessor and Energy Plus / Design Builder until reaching a convergence. The iterative method results showed significant agreement between the measured and modeled data; with a correlation of 98 percent and errors with mean bias error and normalized root mean square error of -1.0 and 7.6 percent; respectively. On the other hand, the Energy Plus method, integrating the Xing approach, showed significantly divergent results between the simulated models versus the measured data. The calibrated model analysis evaluation, using the Fanger’s thermal comfort model, showed satisfactory results within the thermal comfort sensation range. The research results significance indicates that the precise customized detailed iterative method is essential to create the needed inputs which subsequently lead to near-to-actual outputs compared with other ground-contact simulation methods. In fact, the precise customized detailed iterative method approach may be used as a benchmark for simulators for easy and precise ground temperatures’ calculations and earth-sheltered buildings’ simulations.

Keywords

• Thermal comfort
• Basements’ Evaluation
• Ground Temperature Calculation
• Hot-arid Climates.