Perceived Control of Stratum Ventilation

Current control strategies for central air conditioning typically adopt a machine-centered, energyconsuming approach that focuses on creating constant, uniform neutrality-conditions whichmight actually be perceived by some occupants as thermal monotony or sensory deprivation.There are needs for more sophisticated and responsive environmental control strategies,enhanced levels of thermal comfort and acceptability among occupants. Stratum ventilation, anew ventilation mode proposed recently by the authors, has the potential to strike a balancebetween fully automated controls at the system side and manual controls that the users are able toalter. Stratum ventilation should be integrated with specific control strategies for variousapplications and varieties of control option available to occupants. A working example usingCFD simulations is given to illustrate the performance of the proposed new system. Fresher air isdirectly introduced to breathing zone hence air age of the air layer should be younger. Airtemperature gradient is low in the occupied zone. Because less fresh air bypasses occupants,fresh airflow rate may be reduced. The air supply temperature is usually high for stratumventilation. The evaporating temperature of the refrigerating plant can also be lifted, which results in higher coefficient of performance.