The Heat, Ventilation, Air Conditioning (HVAC) systems in urban buses promote high particle motion. In this paper the effect of centralized roof-top HVAC on virus transmission by droplets caused sneezing and coughing was studied with Lagrangian approach while through aerosols breathing talking modeled Eulerian tracer method. It found that large (> 200 μm) can travel more than 3 m without being ...

Underground traffic tunnels serve as the entry and exit buildings for underground spaces. Most of ventilation air-conditioning systems in spaces rely on cooling or preheating to save energy. The temperature distribution has always attracted attention researchers. In this study, a heat transfer model tunnel was established based energy conservation boundary layer theory, field test carried out. ...

Heat pump technology has been used for heating, ventilation, and air-conditioning in domestic and industrial sectors in most developed countries of the world including South Africa. However, heat pump drying (HPD) of fruits and vegetables has been largely unexploited in South Africa and by extension to the sub-Saharan African region. Although studies on heat pump drying started in South Africa ...

–The objective of this work is to study the performance of a split air conditioning system with and without a Matrix Heat Exchanger (MHE) .The experiment was done using HFC134a as the refrigerant and Polyol-ester oil (POE) as the conventional lubricant in the air conditioning system. The performance of the split air conditioning system with HFC134a/POE oil system was compared with HFC134a/POE o...

An operational cost minimisation model is established for a smart energy hub (S.E. Hub) consisting of combined heat and power (CHP) unit, heating, ventilation air-conditioning (HVAC) system, thermal electricity storage units. The optimal operation CHP with the load management HVAC under time-of-use (TOU) tariff. split ratio dynamically determined during operation. scheduling charging/dischargin...

Attic design and construction have significant impacts on residential buildings’ energy performance. In order to understand how passive ventilation rates affect ridge-vent attic’s performance, a twodimensional steady-state finite volume model is employed to simulate the buoyancy-driven turbulent ventilation and heat transfer in a triangular attic space of a gable-roof residential building under...

Increasing peak power demand implies the increasing significance of energy storage. Technologies that efficiently store heat and cold are also important for share renewables improving efficiency heating, ventilation, air conditioning (HVAC) systems. The present experimental study investigated dynamic behavior a room with suspended thermally activated ceiling panels filled material containing 60...

In this paper, we present what was learned in the research & design process of a decentralized ventilation system with chilled ceilings for a commercial office in Singapore. We make two key observations from the knowledge gathered. First, we observe, in quantitative terms, that present-day radiant cooling panel products may not provide sufficient sensible cooling capacity for commercial offices...

A scheme that couples a detailed building energy model, EnergyPlus, and an urban canopy model, the Town Energy Balance (TEB), is presented. Both models are well accepted and evaluated within their individual scientific communities. The coupled scheme proposes a more realistic representation of buildings and heating, ventilation and air-conditioning (HVAC) systems, which allows a broader analysi...