The present study investigated theoretically the exergy performance of floor heating, radiators, and air heating under three different space loads 10, 30 50 W/m2. effects supply return water temperatures were studied for system. All systems assumed to be connected a boiler. system was further analyzed assuming an air-to-water heat pump, ground-source pump. Floor optimal due its low demand. sepa...

The present paper is a review on methods and technologies for air cleaning from micro organisms and viruses, which are applicable with the present HVAC practices. The advantages and the drawbacks of air dilution, filtration (HEPA, ULPA), ultraviolet germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification is c...

background: xylene is known as one of the most toxic of the nervous system. the purpose of this study is to estimate the concentration of xylene in the cabin of the vehicles production in iran. also the effect of ventilation, cigarette smoking, and air freshener inside the vehicle, fuel type and car decorations on the concentration of the substance being studied.   methods: 152 vehicles pride a...

This paper reports an experimental study on a sleeping thermal manikin in a room equipped with a mixing ventilation system. In the experimental work, heat loss from the sleeping thermal manikin was measured under different conditions. The supply air temperature was in a range of 17°C to 27°C. Apart from the heat loss of the sleeping thermal manikin, the velocity distributions and temperature di...

Increased awareness of the impact of chlorofluorocarbons (CFCs) on the global environment has become the impetus in searching for alternative refrigerants and cooling methods for automotive air conditioning. Automotive air conditioning is one industry that heavily uses CFC compounds, and the leakage of CFCs from such air conditioners is substantial compared to that from stationary air condition...

In order to achieve feasible and copacetic low energy consuming building, a robust and efficient air conditioning system is necessary. Since heating ventilation and air conditioning systems are nonlinear and temperature and humidity are coupled, application of conventional control is inappropriate. A multi-input multi-output nonlinear model is presented. The temperature and humidity of thermal ...

In this paper a novel Optimal Type-2 Fuzzy Proportional-Integral-Derivative Controller (OT2FPIDC) is designed for controlling the air supply pressure of Heating, Ventilation and Air-Conditioning (HVAC) system. The parameters of input and output membership functions, and PID controller coefficients are optimized simultaneously by random inertia weight Particle Swarm Optimization (RNW-PSO). Simul...

The shape of the air flow in the interior is heavily influenced by the air distribution system and the way air enters and exits. By numerically simulating flow by computational fluid dynamics, one can determine the flow pattern and temperature distribution and, with the help of the results, provide an optimal design of the air conditioning system. In this study, a chamber was first constructed ...