Simplified model for estimating the neutral pressure level in the elevator shaft of a building

Abstract

This paper presents a simplified model for estimating the locations of the neutral pressure levels (NPLs) in elevator shafts. The proposed model considers the mass balance of airflow based on the vertical zoning of the elevator shafts. To verify this model, the heights of the NPLs and pressure distributions as estimated by the model for three high-rise buildings with different shaft zoning plans were compared with field measurement data. The NPLs in multi-zone elevator shafts exist at different locations, and each set of measured results is consistent with the proposed model with the error within approximately 8% of the building height. Then, infiltration results from the proposed model were evaluated by comparison with simulations, to further validate the feasibility of this model. The proposed model can present a plot curve similar in shape to that provided by a simulation, such as in regard to making calculations separately for sections in which infiltration and exfiltration occur. The results show that this model can quickly estimate the NPLs with satisfactory results for both the architectural designer and the HVAC engineer. Therefore, the proposed NPL estimation model can be used to evaluate pressure difference values and airflow patterns in high-rise buildings in the planning stage.