Lawrence Berkeley National Laboratory

This study used an advanced airflow, energy and humidity modelling tool to evaluate the potential for residential mechanical pre-cooling strategies to reduce peak electricity demand. Simulations were performed for a typical new home in all US DOE Climate Zones. The results show that the effectiveness of pre-cooling is highly dependent on climate zone and the selected pre-cooling strategy. The expected energy trade-off between cooling peak energy savings and increased off-peak energy use is also shown. Best pre-cooling results for most climates were obtained using a short pre-cooling time window with a high pre-cooling set point temperature. All pre-cooling strategies caused the annual cooling energy demand of the simulated buildings to increase. However, pre-cooling for long time periods with a low temperature set point can eliminate up to 97% of the annual peak cooling load of the building.