Dynamic Energy Simulation for a Tiny House Targeting a Net Zero-Energy Building

Achieving net-zero energy performance requires that a building’s total annual energy demand be fully met by renewable energy sources. In this context, the integration and appropriate sizing of renewable energy systems are critical to ensuring balanced and reliable building operation. This study presents a comprehensive dynamic energy simulation of a tiny house designed to achieve net-zero energy building (nZEB) performance. The primary objective is to determine the required sizing of the renewable energy supply system (RESS) to enable net-zero operation. A ground-source heat pump (GSHP) and photovoltaic (PV) panels are considered as the main components of the RESS. To ensure accurate system integration, the tiny house and the RESS are simulated simultaneously using TRNSYS. Peak heating and cooling loads are calculated, and the RESS is sized to satisfy both thermal and electrical demands. Monthly and annual electricity balances are systematically evaluated to verify compliance with net-zero energy criteria. The tiny house features a gable-roof configuration with a floor area of 20 m². The peak heating load, peak sensible cooling load, and peak total cooling load are determined to be 2.12 kW, 1.78 kW, and 2.48 kW, respectively. Based on these results, a GSHP is selected with a rated heating capacity of 2.22 kW at a typical entering water temperature (EWT) of 0 °C for ground-loop operation, and sensible and total cooling capacities of 1.93 kW and 2.69 kW, respectively, at a typical EWT of 25 °C. The required vertical borehole depth is calculated to be 60 m. To meet the annual electricity demand, PV panels with a total installed capacity of 2.27 kWp are required.