Search results
Results from the WOW.Com Content Network
The cooling load temperature difference (CLTD) calculation method, also called the cooling load factor (CLF) or solar cooling load factor (SCL) method, is a method of estimating the cooling load or heating load of a building. It was introduced in the 1979 ASHRAE handbook.
The COP of absorption chillers can be improved by adding a second or third stage. Double and triple effect chillers are significantly more efficient than single effect chillers, and can surpass a COP of 1. They require higher pressure and higher temperature steam, but this is still a relatively small 10 pounds of steam per hour per ton of cooling.
In the United Kingdom, a Seasonal Energy Efficiency ratio (SEER) for refrigeration and air conditioning products, similar to the ESEER but with different load profile weighting factors, is used for part of the Building Regulations Part L calculations within the Simplified Building Energy Model (SBEM) software, and are used in the production of Energy Performance Certificates (EPC) for new ...
In the United States, the efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute, a trade association, in its 2008 standard AHRI 210/240, Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment. [1]
A liquid (glycol based) chiller with an air cooled condenser on the rooftop of a medium size commercial building. In air conditioning systems, chilled coolant, usually chilled water mixed with ethylene glycol, from a chiller in an air conditioning or cooling plant is typically distributed to heat exchangers, or coils, in air handlers or other types of terminal devices which cool the air in ...
When the two temperature differences are equal, this formula does not directly resolve, so the LMTD is conventionally taken to equal its limit value, which is in this case trivially equal to the two differences. With this definition, the LMTD can be used to find the exchanged heat in a heat exchanger:
An example two-stage process is shown at right. (Bottom on mobile) The cascade cycle is often employed for devices such as ULT freezers. [1] In a cascade refrigeration system, two or more vapor-compression cycles with different refrigerants are used.
As an example the combustion process inside a power stations gas turbine is highly irreversible and approximately 25% of the exergy input will be destroyed here. For fossil fuels the free enthalpy of reaction is usually only slightly less than the enthalpy of reaction so from equations ( 3 ) and ( 4 ) we can see that the energy efficiency will ...