Document 4XqXvONMX83qx7w9eMDdvDEG
936
CHAPTER 65
1965 Guide And Data Boole
ROUP A FACTORY ASSEMBLED REFRIG
ERATION SYSTEMS
SPLIT REFRIGERATION SYSTEMS PLUS REMOTE CONDENSERS
OROUP C
GROUP O
SPLIT REFRIGERATION SYSTEMS PLUS FACTORY ASSEMSLEO REFRIGERATION
REMOTE COMBEUSING UNITS
SYSTEMS PLUS REMOTE MATER CHILLER
Unifdry Air Conditioners..
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937
include air-cooled, water-cooled, and evaporatiyely-oooled
multi-piece .systems up,..to. 100 tons, equipment may i.be
located in the conditioned space or outside the conditioned
space, with or without ducts. In the conditioned space,-'units
may be either floor-mounted, wall-mounted, ceiling-mounted,
or window- or transom-mounted. Outside the conditioned
space, equipment may be located in a special equipment room,
on the roof top, in an attic, in the basement, yard, garage, or
in.a crawl,space.-
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.. A recent trend is to the use of year-round unitary equipment
for > multi-room apartments. .Aircooled condensing sections
for; such application- arei.mounted, through; the -,toaU and de
signed for complete service access from indoors. -
T GmERAt .DESIGN CONSIDERATIONS .
Sizes
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OapftcitiFw of units presently'extend .up to 100 tonS;with
the top limit subject to.upward pressure in recent yeara^The
industry has not standardized oh capacity steps within this
limit, and therefore, no.aeriM..af.standard sizes is available
for dwrign purposes. Certified`capacity ratings in accordance
with the ARI .unitary.-.air .conditioner;certification program
must be stated in increments of.lOOO-BtQh.1'* - , i
;;
- Participation in'the certification program is voluntary, and
the programm limited to-units of armaarimum capacity, of
135,000Btoh.
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-> In ;sizes up to 7$itons,-the industry presently builds
equipment having capacity*ratings at almost every.step of the
ment offered by .the industry.*
Shapes and Configurations
No particular pattern has been established in, the industry for either die shape or arrangement .of components for uni tary air-conditioning .equipment. Thus,' the designer'has'a relatively free'choice within the scope of equipment classifica tions with regard to shape, 'size, and general 'arrangement. Equipment is offered in both vertical and horizontal groupings of components for'floorj wall-hung,'ors`ceilihg suspension. Units are also 'designed for' matching' use' with auxiliary heating equipment, 'such as forced warm air furnaces, which in turn are offered in vertical upflow,' vertical' downflow, and horizontal models. Fjg"2to' 9 illustrate typical arrangements'.*
Appearance
Unitary air conditioners 'can tie separated into two classifi cations based on appearance and depending upon tire location of the equipment.' When designed for use within tire' condi tioned space, cabinets'and grilles are ,'attractively styled to match the general surroiindinga When'used'outside the con^ ditioned space, styling is less important. Wheni used outdoors, the units must be weather-proofed. -
Codes and Standards
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In the design of unitary (equipment, a large number of codes and standards covering construction, performance testing,- and application must be: considered. A few. of these
,..Rg. 2..... Typical Vertical Water-Cooled Single^ ..''" Padcoge Unit*
are of, minor importance and in some instances^ the,'require^ inents are in conflict. In most localities, city or state building codes require compliance with some of these standards.
listed below are most of the significant codes and stand ards which concern the design, testing, and rating of unitary equipment. These are all national in scope.- No effort has been made to indicate their relative importance which would
UPPLT DUCT'
F9: ,4 . .... Pre-:Chqrged Split System with Throughthe-Wdll Condehsing Unit*
be determined by:the type of,unit, its marketing area,-and
compliance requirements of local codes.
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1. ARI 210-64 2.; ASHRAE 37-60
3.' UL 465 4. ASA-B9.1 '5.;FHA-300 6..CSA - - ~r
7. AGA ' : '
8. NFPA-70 NBFU
9. 1CBA 10. NFPA 11. NBFU 12. ASA B31.5
Unitary Air-Conditiooing Equipment '
Methods of Testing For Rating UnitaryAir Conditioners. Air Conditioners, Central Cooling ,
Safety Code for Mechanical Refrigeration' FHA Minimum Property Standards'1' 1
Standards-for Air-Conditioning and-Re-frigeration Equipment .
Standards for Applicable ` Gas^Fired
Equipment Used aa Components of Uni tary Air Conditioners
National Electrical Code National Building Code Uniform Building Code
Fire Prevention Code Pamphlet 90B_ Code for Pressure Piping
ENGINKR1NG DESIGN DETAILS
Table 1 summarizes current practice with respect to engi neering design details for unitary air conditioners. In general, the values indicated represent the maximum and minimum design values for current units. Many have become industry design standards as established through the ARI. .
The design of a complete refrigeration system to produce a
RETURN DUCTtVAPORATOR
COMPRESSOR
CONDENSER
Rg. 3 .... Typical Horizontal Air-Cooled Single*' ` Package Unit*
Rg. 5 .... Typical .Split System . Installations, of,.Remote Air-Cooled Condensing Unit with Cooling Coil or ~ ' Coil-Blowers*'
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