Description

In this case the single zone office building will be cooled using natural displacement-ventilation and a chilled floor. Ventilation openings are located in the North (high level outflow) and south façade (low level inflow). The windows are open during working hours. In order to maintain stratification even when the inside temperature is lower than outside a solar chimney is used.

Cooling Strategy

Outside air cooled by contact with the chilled floor is used to remove heat from the building in a displacement-ventilation configuration with a solar chimney.

EnergyPlus Models Used

Displacement-Ventilation model (UCSD Displacement Ventilation)
COMIS (buoyancy driven airflow)

Simulation Results

Analysis

The largely decreased number of hours where flow is reversed resulted in a noticeable decrease in overheating hours, as well as improved airflow quality and stability.

The use of a chimney with a black internal surface allows for efficient use of the collected solar energy: because the chimney volume tends to have an air temperature that is much higher than the outside it becomes possible to maintain stratified flow even when the occupied zone is below outside temperature.