dimax knowledge Base

  • A heat pump is a device that uses the refrigeration cycle for heat recovery. Normally thermal energy transfers from a hot body to a cold body. A heat pump uses external energy to transfer thermal energy in the opposite direction, that is to absorb heat and then reject it to ‘heat sink’. The simplest example […]
  • All chillers use some form of external energy to move or ‘pump’ heat from a low temperature medium to a high temperature medium. Electric chillers use compressors to move heat to a higher temperature medium for heat rejection. Absorption chillers achieve this heat transfer by using an external heat supply such as hot water or […]
  • Dew point temperature is the temperature when the water vapour present in air begins to condense. The dew point can also be defined as the temperature at which the outside air becomes completely saturated with moisture. If the dew-point temperature is close to the dry bulb temperature –  the relative humidity is high If the […]
  • Dry bulb temperature is the temperature that is read by the sensing element on an ordinary temperature sensor or thermometer. Dry-bulb temperature does not take into account the effect of moisture in the air. The wet bulb temperature takes into account the effect of moisture in the air and its effect on the sensing element […]
  • Some central chilled water systems connect the evaporators on multiple chillers in series.  That is, return chilled water flows through the first chiller and then the next chiller, and controls are set so that each chiller covers part of the required cooling range. The idea in this type of connection is that it is better […]
  • Tower free cooling is a term used when a cooling tower is operated at low temperatures to produce chilled water when the outdoor conditions are suitable. The idea is to get chilled water without running chillers if outdoor temperatures are low enough. If tower free cooling is handled with an open evaporative cooling tower, then […]