Field measurements on thermal stratification and cooling potential of natural ventilation for large space buildings

Abstract

Large space buildings often have high HVAC energy consumption, and the thermal pressure ventilation can be utilized to reduce the using of chiller. Temperatures were tested on two naturally ventilated large spaces, and it increased linearly towards the ceiling with its gradients α being in range of 0.1–0.4 °C/m. The traditional stack effect model is modified by introducing thermal stratification. For three hot and humid cities in China, the acceptable indoor air temperatures are discussed and determined based on its monthly outdoor air temperatures. Investigations are done to find out parameters’ influences on the indoor thermal environment. It is known that both the dimensionless neutral plane height H_n/H and the volumetric flow rate per unit floor area l are not sensitive to outdoor climate, but decrease with increasing of the lower-upper opening area ratio R_ab; the occupied air temperature t_n increases with the increase of R_ab or q but with the decrease of α or H; under case of 0.2 °C/m and 150 W/m², Nanjing has the maximum scopes of available upper opening areas in transition season to achieve natural ventilation cooling potential. Such results would be useful in design and management of upper openings for large spaces.

Keywords:

• Large space
• thermal stratification
• natural ventilation
• opening area ratio
• occupied air temperature

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China under Grant number 2018YFC0704303; and Postdoctoral Science Foundation of China under Grant number 2015M581783; and Postdoctoral Research Funding Plan of Jiangsu Province, China under Grant number 1501066B.z