Implications of latent and sensible building energy loads using natural ventilation

Abstract

Building decarbonization requires balancing energy efficiency with occupant comfort. Sensible cooling and latent loads, traditionally addressed by air conditioning, are significant contributors to energy use. This study explores an innovative approach to utilize natural ventilation through windows when outdoor conditions are favorable. The novelty of this work lies in its comprehensive consideration of sensible and latent loads, including both humidification and dehumidification, within the context of natural ventilation. When in cooling mode, if the indoor temperature rises above the cooling set point and the outdoor temperature is lower than the indoor temperature, the windows will automatically open to enhance natural ventilation, provided the specific humidity conditions for indoor, outdoor, and set point are met. Simulations using the Vertical City Weather Generator (VCWG v1.4.7) software investigate the energy savings potential in Toronto, Vancouver, and Phoenix for 2020. Results indicate potential for notable annual total cooling load savings of 5–15 kW-hr m−2 Year−1. Additionally, further analyses examine the impact of building air-tightness, envelope thermal resistance, and climate zone on the effectiveness of natural ventilation to reduce the sensible cooling, latent, and total cooling loads.