1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1985 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001INFORMATIONREPORTAn American National StandardJ169REV.MAR85Issued 1970-0
4、7Revised 1985-03Superseding J169 APR80(R) DESIGN GUIDELINES FOR AIR CONDITIONING SYSTEMS FOR OFF-ROAD OPERATOR ENCLOSURESForewordThis Document has also changed to comply with the new SAE Technical Standards Board format.The experience gained from automotive air conditioning is very important, but it
5、 must be remembered thatoperating conditions for automobiles and off-road equipment are vastly different. Off-road equipment must bedesign to meet severe conditions of heat, dust, vibration, and general rough usage.1. ScopeThe purpose of this document is to establish air conditioning design guidelin
6、es that will apply to mostsystems rather than the specific design of any particular system. Operating conditions and characteristics ofthe equipment will determine the design of any successful system, and since these characteristics andconditions vary greatly from one application to another, the des
7、igner must determine the goals expected to bereached under the conditions encountered. To determine the capacity of such items as blowers, condenserfans, condenser coils, evaporator coils, filters, compressors, etc., will require the adherence to severalguidelines, some of which are outlined in the
8、following paragraphs.2. References2.1 Applicable PublicationThe following publication forms a part of the specification to the extent specifiedherein. Unless otherwise indicated the lastest revision of SAE publications shall apply2.1.1 SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warre
9、ndale, PA 15096-0001.SAE J898 JUL822.2 Related Publications2.2.1 OTHER PUBLICATIONSFrank Eischen, “Producing a Quiet and Comfortable Cab.“ Paper 680587 presented at SAE Farm,Construction, and Industrial Machinery Meeting, Milwaukee, September 1968.B. F. Vogelaar, “Engineering and Operational Charact
10、eristics of Air Conditioning Cab.“ Paper 59639presented at ASAE meeting, December 1959.ASHRAE Guide and Data Book, Vol. 1, Fundamentals and Equipment.3. DefinitionsSAE J169 Revised MAR85-2-3.1 Size Of Operator EnclosureThe size of the operator enclosure must be considered and the number ofriders tha
11、t may normally be in the operator enclosure.3.2 Air FlowThe position of the cooling vents and direction of air flow will affect the comfort of the operator andmay be more important than the average temperature in the operator enclosure.3.3 GlazingThe amount and type of glazing in an operator enclosu
12、re becomes a very definite factor in thedesign of an air conditioning system. It is usually possible to insulate the operator enclosure walls, roof, floor,etc., but very little can be done in the glazing area unless thermopane glass is used and this is not too practicalfrom the standpoint of cost. I
13、f plastic is used instead of glass, the relative heat transfer should be considered.Tinted glass may be used to advantage, if visibility is not affected.3.4 InsulationThe extent of insulation required is determined by the capacity of the air conditioning system andby the ambient conditions expected.
14、 Solar radiation is one area of use that may require considerable insulationin the roof area. Heat generated by the engine and by hydraulic equipment may require more insulation in firewalls and floor plates than would usually be expected.3.5 Sealing Of OpeningsIf an operator enclosure is used in ex
15、tremely hot ambients and unless the airconditioner is of very high capacity, it will be necessary to recirculate some of the operator enclosure air. Whenall or a major portion of the operator enclosure air is recirculated, it is necessary that the operator enclosure bewell sealed. When it is not nec
16、essary to recirculate the operator enclosure air and all outside air is inductedthrough the air conditioning system, a ventilator should be provided in the operator enclosure. This ventilatorshould be located in a position relative to the cool air vents that will allow the cool air to circulate thro
17、ugh theoperator enclosure in a manner to achieve maximum cooling. In all cases, the vent should be a size that willpermit a slight pressurization within the operator enclosure. This pressurization will prevent the entrance ofdust and hot air through any cracks or small openings that are not sealed.3
18、.6 Ambient ConditionsTo be successful, an air conditioning system must have the ability to achieve adesirable temperature level when operating in any ambient expected to be encountered. High temperature andhigh humidity perhaps create the most difficult conditions, but the presence of dust also crea
19、tes problems.Regardless of how often a filter is changed or cleaned in extreme dust conditions, there will be some cloggingof the filter. The filter, therefore, must be large enough to allow sufficient air passage even though it is partiallyclogged with dust. The dust conditions also determine the s
20、ize of the evaporator blowers and the condenserlocation. In some systems, it may be practical to locate the condenser coil upstream of the vehicles radiatorand, if this can be done, it will give good results; but careful consideration must be given to the problem of dustand dirt clogging the coil an
21、d then cutting down the efficiency of the radiator. The alternative is to mount thecondenser in some other location and cool it with a motor driven fan or fans. The advantage of cooling withmotor driven fans is that the condenser can be mounted in the best possible location relative to the rest of t
22、hesystem and freedom from dirt and dust. The size of the condenser coils, location, and air flow must be suchthat the head pressure at the compressor does not exceed 300 psi continuous or the manufacturersrecommendations. The head pressure will be determined by the temperature of the refrigerant at
23、the inlet ofthe expansion valve.3.7 Accessibility Of Serviceable ComponentsTo assure the proper servicing of the filter, it must be located soit can be removed and replaced with a minimum effort and without the need of special tools. Provisions mustalso be made to prevent the accumulation of dust an
24、d dirt on the filter from falling on the operator when thefilter is removed. Even with the use of a filter, some dust will eventually accumulate on the evaporator coil and,therefore, the coil should be located so it can be cleaned when necessary. Controls, switches, hose, belts, etc.,may require rep
25、lacement and this should be possible without major disassembly.3.8 Refrigerant LinesSuction line from evaporator to compressor should be as short as possible and ofsufficient size to keep pressure drop to a minimum. Fittings, such as self-sealing couplings, will create somepressure drop, and their d
26、esign should be considered.SAE J169 Revised MAR85-3-3.9 NoiseFans or blowers can create objectionable noise and vibrations in an operator enclosure if not properlylocated and balanced.3.10 Evaporator Condensate ControlIn humid conditions, a considerable amount of condensate accumulateson the evapora
27、tor coil, and provisions must be made to prevent this from being carried into the operatorenclosure by the air stream, or from leaking in if the evaporator is in the operator enclosure roof. If theevaporator is ahead of the blower, as much as 2 in water gage negative pressure may result and this mus
28、t beconsidered in the design of drip pan and drains.3.11 Power RequirementSufficient power must be available to operate fans, blower, and compressor clutch. Theamount of power required is considerable and the output of the machines electrical system may not besufficient. It may be necessary to use a
29、 large capacity generator and heavy duty battery, if an electric motor isused to drive the condenser fan.3.12 DurabilityMost designers of off-road equipment and accessories for such equipment are well aware of theshock and vibration usually encountered, and therefore, should make provisions in an ai
30、r conditioning systemto withstand such conditions. This may require shock mounting of some components. Sheet metal parts mayhave to be fastened together with bolts and lock nuts rather than sheet metal screws. Systems designed fortrucks and automobiles are not always sufficiently durable to withstan
31、d the shock and vibration of off-roadequipment, especially that which is track mounted, such as crawler tractors.3.13 ConvenienceAll controls, switches, etc., should be positioned for the convenience of the operator. See SAEJ898 JUL82.3.14 Operator ConsiderationsAll components should be positioned i
32、n such a manner that they will not hamperthe operator when entering or leaving the enclosure, or while operating the equipment. It is very important toposition air intakes so that exhaust gas will not be drawn into the operator enclosure.4. Notes4.1 Marginal IndiciaThe change bar (l) located in the
33、left margin is for the convenience of the user in locatingareas where technical revisions have been made to the previous issue of the report. An (R) symbol to the leftof the document title indicates a complete revision of the report.PREPARED BY THE SAE OFF-ROAD MACHINERY TECHNICAL COMMITTEESAE J169
34、Revised MAR85RationaleSAE J169 is being revised to develop a single document which would include all off-roadequipment. The original document was written for construction and industrial equipment only.As part of the five year review the introduction was revised to delete reference to an automobile t
35、rip andthe reference list was reviewed. Many of the references were part of the original document which werenot deleted when the document was changed in later revisions.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThe purpose of this document is to establish air conditioning
36、 design guidelines that will apply tomost systems rather than the specific design of any particular system. Operating conditions andcharacteristics of the equipment will determine the design of any successful system, and since thesecharacteristics and conditions vary greatly from one application to
37、another, the designer must determinethe goals expected to be reached under the conditions encountered. To determine the capacity of suchitems as blowers, condenser fans, condenser coils, evaporator coils, filters, compressors, etc., willrequire the adherence to several guidelines, some of which are
38、outlined in the previous paragraphs.Reference SectionSAE J898 JUL82Frank Eischen, “Producing a Quiet and Comfortable Cab.“ Paper 680587 presented at SAE Farm,Construction, and Industrial Machinery Meeting, Milwaukee, September 1968.B. F. Vogelaar, “Engineering and Operational Characteristics of Air Conditioning Cab.“ Paper 59639presented at ASAE meeting, December 1959.ASHRAE Guide and Data Book, Vol. 1, Fundamentals and Equipment.Developed by the SAE OFF-ROAD MACHINERY TECHNICAL COMMITTEE
