III. INDUSTRY DEVELOPMENTS 



There are 89 manufacturers listed in the American Society of Heating, 

 Refrigeration, and Air Conditioning Engineers (ASHRAE) 1976 Product 

 Directory as sources of air-cooled condensing units for split systems in 

 the range between three and fifteen tons. Thirty-eight of these manu- 

 facturers and an additional six firms make similar equipment in sizes 

 over fifteen tons capacity. With few exceptions, manufacturers in the 

 above groups also make self-contained units of various types in the same 

 size ranges. 



As part of this cost/effectiveness investigation, an inquiry question- 

 naire was sent to eleven equipment manufacturers selected primarily from 

 those who had previously indicated a desire to work with NAVFAC on air 

 conditioning components for a proposed modular building program,, Since a 

 number of these manufacturers did not fabricate their own condensers for 

 air-cooled equipment, inquiries on condenser fabrication and coating 

 practice were sent also to three coil fabricators, two coil coaters, and 

 two suppliers of potentially applicable metal finishing products . A 

 number of other industry sources and suppliers, including Reynolds Metals 

 Co., were interviewed by phone. Responses to these inquiries are the 

 source of information for industry practices and current industry 

 developments presented below. 



Coil Design and Fabrication 



In spite of the myriad of possible combinations in which air conditioning 

 components can be and are assembled to form working systems, the opportunity 

 for custom selection of condensing equipment to be applied in such systems 

 is limited. Compressors, condensers, and condenser fans, are sold as 

 packaged condensing units to be used with remote, direct expansion com- 

 ponents. Assembled with direct expansion water coolers and water circulating 

 pumps, compressors and air-cooled condensers are sold also as packaged water 

 chillers for systems when water is circulated as a heat transfer medium. 

 Rooftop units and window air conditioners are typical of another class of 

 equipment package containing direct expansion coils and integral blowers 

 to be used where air is circulated as a heat transfer medium. These units 

 often contain gas furnaces or electric heating elements, or, alternatively 

 can be arranged for year-round operation as heat pumps. Thus, increasingly, 

 cooling equipment manufacturers are selling "packages" in which there is no 

 design option to specify condenser materials or performance. 



It is the opinion of the Carrier Corporation Corporate Research and 

 Development Department that industry efforts over the years have resulted 

 in a highly cost-effective air condenser for package units; and that there 

 would be no advantage whatsoever for any kind of coating, or returning 

 to all-copper condensers for good, long-term performance at normal, 

 inland locations „ However, a number of other manufacturers indicated that 

 they are actively pursuing, or interested in becoming involved in, or 

 are following closely potential coating applications. Presumably, 

 coatings are seen as having competitive advantage because the same 

 manufacturers, in general, indicated that they were responding in various 



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