Heat and Humidity Transport Analysis Inside a Special Underground Building

The calculation of heat and humidity load serves as the cornerstone of Heating,Ventilation,and Air Conditioning(HVAC)design.Nevertheless,as the heat and humidity load characteristics of underground structures differ substantially from those of above-ground structures,it is a challenge to derive their accurate calculation procedure through engineering experience.Therefore,it is particularly important to carry out quantitative research on heat and humidity load.This study used Design Builder software to study the influence of the design state point of air conditioning in underground buildings on energy consumption.The study showed that compared with the single design temperature of 18℃,setting the temperature of 16℃ in winter and 22℃ in summer could reduce energy consumption by about 59%.And the hourly heat load,cooling load and humidity load in one year are simulated and calculated so as to quantitatively analyze the characteristics of the load.This provides a database for selecting suitable HVAC equipment.It is further emphasized that dehumidification is the key to HVAC design of underground structures,which provides a reference for similar engineering designs.

Coupled heat and moisture transfer in walls featuring moisture-buffering materials and ventilating layers:An Experimental study

The moisture performance of building envelopes largely depends on the building materials,construction tech-niques,and exposure loads from the indoor and outdoor regions.A ventilated air interlayer placed in a wall can help dehumidify the wall and indoor air.This paper presents an experimental study of the heat,air,and moisture variations within the envelope wall of a chamber featuring different air interlayer settings under real outdoor air conditions during the summer of 2020 in Shanghai,China.Self-developed humidity-controlling building mate-rials were applied to the inner building envelope.Temperature,humidity,wind velocity,and heat-flow sensors were placed at different positions in the middle of the wall.These parameters were measured and recorded in real-time under three working conditions:humidification,dehumidification,and ventilation.The experimental results show that under the ventilation working conditions,moisture content of 0.52 kg can be removed after a 2-h air layer ventilation,which can benefit the design strategy for the humidification and ventilation of dehu-midification walls.