Research On Air Flow And Thermal Comfort Of An Underfloor Air Distribution Room

Indoor air conditioning and ventilation conditions plays an important role in the health and comfort conditions of the person in the room.The traditional commercial buildings air conditioning system is not well positioned to meet the different requirements of temperature and ventilation for different users.Once the system is installed, it’s hard to change the outlet location according to different needs, while using underfloor air distribution system(UFAD), partial adjustment and personalized control can be conducted according to individual needs.Since the UFAD system was proposed,the calculation theory of the air conditioning load is still imperfect, in order to calculate the air conditioning load of underfloor air distribution system, a simplified UFAD load calculation model of air based on stratification theory was introduced. Through the model, the UFAD indoor air supply parameters can be determined, provides a theoretical basis for the numerical simulation of different air supply conditions.A numerical calculation model of UFAD was established to simulate the indoor air-conditioning environment,discussed how does the air velocity, temperature, age of air and the thermal comfort conditions in the room vary with different air supply velocity. The results showed that air supply velocity has a significant influence to the flow distribution,in low air supply velocity,there is obvious temperature stratification along the height direction, The temperature around the human body also maintained at a reasonable range;When The air supply velocity is larger, the thermal stratification phenomenon along the the height direction gradually disappears.In addition, the air supply velocity has little impact on indoor air thermal comfort index PMV/PPD.