Item ID: 23
Indirect-Direct Stand Alone Evaporative Cooler
Cooling Systems in Dry Climates: Indirect-Direct Evaporative Cooling vs. Mechanical Cooling
A device that employs both indirect and direct evaporative cooling instead of using the vapor-compression/refrigeration cycle. This maximizes evaporative cooling while increasing humidity less than direct evaporative cooling alone.
Traditional evaporative coolers use only a fraction of the energy of vapor-compression or absorption air conditioning systems. Unfortunately, except in very dry climates, they increase humidity to a level that makes occupants uncomfortable. Two-stage indirect-direct evaporative coolers do not produce humidity at levels as high as those produced by traditional single-stage evaporative coolers, and so may be useful in a wider range of applications.
According to the Emerging Technologies Coordinating Council, “The existing two-stage evaporative cooler on the market does not achieve the full potential of this technology. Previous lab testing has shown an achieved evaporative effectiveness of 88 to 98%. The OASys product, the result of a CEC PIER Program, appears to be able to achieve the technology potential. Lab and field monitoring has indicated that the OASys technology can achieve evaporative effectiveness from 104 to 111%. "In addition to their widespread use in dry climates, there are many cost-effective applications for evaporative cooling in locations with moderate humidity, including industrial plants, commercial kitchens, laundries, dry cleaners, greenhouses, spot cooling (loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, and kennels) and confinement farming (poultry ranches, hog, and dairy). In western Washington and Oregon, it is surprisingly dry during warm summer days, and indirect-direct evaporative cooling is practical in almost every instance in most locations.
These units do not provide the same comfort as a DX chiller. Because of the added humidity, any cooling cycle that includes direct evaporation, including indirect-direct evaporative cooling, may have little thermal comfort benefit.
Energy Savings: 30%
Energy Savings Rating:
Comprehensive Analysis What's this?
|1||Concept not validated||Claims of energy savings may not be credible due to lack of documentation or validation by unbiased experts.|
|2||Concept validated:||An unbiased expert has validated efficiency concepts through technical review and calculations based on engineering principles.|
|3||Limited assessment||An unbiased expert has measured technology characteristics and factors of energy use through one or more tests in typical applications with a clear baseline. |
|4||Extensive assessment||Additional testing in relevant applications and environments has increased knowledge of performance across a broad range of products, applications, and system conditions. |
|5||Comprehensive analysis||Results of lab and field tests have been used to develop methods for reliable prediction of performance across the range of intended applications.|
|6||Approved measure||Protocols for technology application are established and approved.|
Next Steps based on Identification Stage (Stage Gate 1): Accept
Approved by TAG for shortlist (Stage Gate 2): True
Next steps based on TAG and BPA Scorecards: DecisionTree