Dew-point evaporative cooling is an air conditioning technology which has possibility of achieving lower temperature, higher efficiency, water consumption. Understanding the heat and mass transfer principles system crucial for applications. This study presents a mathematical model conducted to (1) processes under different initial condition; (2) analyze factors affecting performance system. And...

We have developed an analytical model for evaporative cooling [1]. By simulating evaporation as a sequence of discrete steps, we could predict the time dependence of all important parameters such as temperature, density, elastic collision rate. By incorporating trap loss due to background gas collisions into our model we derived the threshold conditions for “run-away” evaporation. This is chara...

Day-and-night radiative sky cooling has emerged as a potential alternative to conventional technologies such refrigeration-based air conditioning and evaporative wet cooling. Both can passively achieve sub-ambient without consuming electricity. Although both techniques are subject impacts from various weather conditions, the extents of under same conditions not well understood. In this work, we...

Evaporation rates are predicted and important transport mechanisms identified for evaporation of water droplets on hydrophobic (contact angle ~110°) and superhydrophobic (contact angle ~160°) substrates. Analytical models for droplet evaporation in the literature are usually simplified to include only vapor diffusion in the gas domain, and the system is assumed to be isothermal. In the comprehe...

Evaporative air cooling is an effective and environmentally benign method of cooling. Scientific evidence demonstrating that chlorofluorocarbon refrigerants (CFCs) are contributing to the destruction of the stratospheric ozone layer have prompted legislative action aimed at reducing the production and use of certain CFCs. Enacted legislation, by necessitating the introduction and use of alterna...

Forced draft evaporative cooling towers are often used for condenser cooling in small steam power plants. Conventional control strategies keep the cooling pump operating at full speed all the time, and control the cooling water temperature by modulating the tower fan speed. In this work, an energy-efficient control strategy is proposed, that minimizes the combined consumption of the tower fans ...