1、Prepared by: a r z Air-Conditioning and Refrigeration Institute m rau Sheel Metal and National Association Air-Conditioning Contractors GUIDELINE 8-1997 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted
2、without license from IHS-,-,-0352320 00107b7 T48 ACKNOWLEDGEMENT These guidelines for Roof Mounted Outdoor Air- Conditioner Installations were prepared by the of the Air- Conditioning and Refrigeration Institute (ARI) and the Sheet Metal and Air-Conditioning Contractors National Association (SMACNA)
3、. Therefore, thanks are in order for efforts by the technical staffs of each organization and the committees within each organization for their review and comments to final- ize this document. Note: This guideline supersedes AR1 Guideline B-1986. Copyright Air-Conditioning and Refrigeration Institut
4、e Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 9 0352320 00107bA 984 D GUIDELINES FOR ROOF MOUNTED OUTDOOR I NSTALLATIO N S AIR-CONDITION ER Prepared by: Air-Conditioning and Refrigeration Institute 4301 N. Fairfax Drive,
5、Arlington, VA 22203 Sheet Metal and Air-Conditioning Contractors National Association 4201 Lafayette Center Dr., Chantilly, VA 22021 June 1997 -I- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted withou
6、t license from IHS-,-,-H 0352320 00107b 810 TABLE OF CONTENTS Page preface . . . . . . . . . 1 Section A-Curb Criteria for Roof Mounted Equipment . . . . . . . 2 Section &Stand Mounting Criteria 3 Section C-Unit Installation . . . . . . . 9 Section D-External Connections D-l-Exterior Duct Closures a
7、nd Connection to Equipment . 11 DB-Electrical 15 D-%Piping . . . . . . . . . .16 D-4-Drains 19 Section E-General Instructions E-1 -Checklist for Equipment Installation and Service 20 E-2-Flashings . . . . . . . . . 21 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under licen
8、se with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-W 0352120 0010770 532 PREFACE This document contains guidelines for the installation of roof mounted outdoor air-conditioner equipment as developed and agreed upon by the Air-Conditioning & Refrigeration In
9、stitute (ARI) and Air-Conditioning Contractors National Association, Inc. (SMACNA). The purpose of these Guidelines which cover curb and roof penetrations and sealings is to set forth good construc- tion practices. The Guidelines are just that-guidelines- and are not standards, warranties or certifi
10、cations. The information contained in these Guidelines should serve as a supplement to the unit manufacturers specif- ic installation instructions. The precise steps to be taken with respect to a specific curb, roof penetration or sealing may vary according to particular circumstances, job con- diti
11、ons and manufacturers specifications. In all cases, the necessary installation work should be done by and under the supervision of skilled and qualified personnel. These Guidelines cover instructions on the interface between the roof and the location at which the unit, pip- ing, electrical wiring or
12、 sheet metal ductwork pass through the roof. For more detailed design information, see the SMACNA Architectural Sheet Metal Manual, HVAC Duct Construction Standards, and the National Electrical Code. These documents were the source for many of the recommendations made in these Guidelines. No changes
13、 in these AR1 - SMACNA Guidelines shall be made without the approval of AR1 and SMACNA. -1 - Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I m 0352320 000771 477 m Sectio
14、n A Curb Criteria for Roof Mounted Equipment 1. 2. 3. 4. 5. 6. 7. The top of the curb should be level after installation. The curb and the equipment should be structurally capable of supporting intended loads and should be so designed that no penetration for drains, power lines, etc., will occur thr
15、ough the roof flashing. The curb should be furnished with a wood nailer which provides a minimum of 3-/2 inches of nailing surface, mounted at the top of the curb, to permit mechanical attachment of the flashing material. Caution should be used when considering the use of wood that has been treated
16、with an oil borne preser- vative for wood nailers. The oil that is used in many lumber treatments can act as a solvent on roofing materials and can cause bitumen drippage. When wood nailers constructed of wood that has been treated with an oil borne preservative are used, a barrier of rosin-sized sh
17、eathing paper or similar material should be placed between the built-up roof membrane and the nailer. The curb should provide a minimum clearance of 1 O inches between the top of the finished roof surface and the top of the wood nailer, continuous around the curb perimeter. In no case should the cur
18、b be less than 14 inches in height. (See Figure 6.) If the curb does not include a counterflashing receiv- er, a separate counterflashing receiver should be installed prior to the installation of the equipment. All receivers should be of watertight construction. The metal counterflashing may extend
19、down over the base flashing so that no composition material is exposed, thereby reducing the danger to foot abuse. (See Figure 6.) -2- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license fr
20、om IHS-,-,-0352320 O030772 305 Section B Stand Mounting Criteria Some mechanical equipment installations require that roofing materials be installed or maintained beneath them.Table 1 presents guidelines for the clearances nec- essary to accomplish this purpose. Units which allow access from the sid
21、es may permit reduction of these val- ues. Typical methods for flashing of unit supports are shown in Figures 1 through 5. Table 1 WORKING CLEARANCES Width of Height Above Equipment Roof Surface Up To 24“ 14“ 25“ To 36“ 18“ 37“ To 48“ 24“ 49“ To 60“ 30 61 “ And Wider 48“ -3- Copyright Air-Conditioni
22、ng and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m 0352320 0030773 293 m Figure 1 Mechanical Equipment Stand PIPE COLUMN -4- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS u
23、nder license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure 2 Insulated Steel Deck Frame STRUCTURAL FRAME WATERTIGHT UMBRELLA OVERLAPPING JACK BY MINIMUM OF4 SHEET METAL ROOF JACK MINIMUMOF 0“ABOVE RMWING 3“ MINIMUMTO 4 MAXIMUM FLANGE SETINMASTCOVER
24、 ROOFING. FASTEN FLANGETOWOOD NAILER (ALL SIDES STRIPPINO. PRIME FLANGE BEkm -.- FASTENED rn STRUCTURAL FRAMINGAC REWIRED -5- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-
25、,-rn 0352320 0030775 0x4 m Figure 3 Concrete Deck And Frame -6- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-D 0352120 OL077b T50 D Figure 4 Equipment Support CAP FLASHI
26、NG NEOPRENE PAD APPROXIMATELY COUNTERFLASHING APPROXIMATELY BASE FLASHING FIBER CANT STRIP- SET IN ETTUMEN NOTE: SEE TABLE 1 FOR RECOMMENDED HEIGHTS FOR STAND ABOVE RM)F SVRFACE -7- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduc
27、tion or networking permitted without license from IHS-,-,- 0352120 0010777 997 rn Figure 5 Flashing Structural Member Through Roof Deck STRUCTURAL SECTION -8- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking perm
28、itted without license from IHS-,-,- 0352320 0030778 823 m Section C Unit Installation 1. 2. 3. 4. 5. 6. WHEN UNITS ARE HANDLED, THE UNIT MANU- FACTURERS INSTRUCTIONS MUST BE CARE- FULLY FOLLOWED. Units should not be moved over a roof membrane but should in some manner be lift- ed from the ground ont
29、o the curb or support frame- work. Seal (to curbing): When setting the unit onto the curb, the installer should ensure that a sealing mate- rial is positioned between the unit and curb to pro- vide a continuous watertight connection. (See Figure 6.) The base of curb mounted units should extend beyon
30、d the curb. (See Figure 6.) Installation should be in accordance with local code requirements. Installation should provide for minimum blockage of snow. Equipment mounting should be of heavy masonry or equivalent construction, or an auxiliary mounting plaform shall be provided, to minimize vibration
31、 effects (see Paragraph 4.1.2 of AR1 Standard 270- 95)“ Sound Rating of Outdoor Unitary Equipment.“ -9- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-D 0352320 0030779 7b
32、T Figure 6 Curb Detail For Rooftop Air Handling Units 3%” MINIMUM - INSULMD” -FWERC*NT STRIP- SETIN BITUMEN -10- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-= 0352120 0
33、010780 Li81 Section D External Connections Section D-1 Exterior Duct Closures and Connection to Equipment 1. All ducts that are not watertight through the use of welded construction or protective shields and are exposed directly to weather and solar radiation should have secure watertight mechanical
34、 connec- tions and receive exterior duct sealant treatment as defined in paragraph 2. 2. Exterior duct sealant treatment should consist of the supplemental application of a product or products marketed specifically as forming a positive air and watertight seal, bonding well to the metal involved, re
35、maining watertight with metal movement and hav- ing a suitable service temperature range. If exposed to direct sunlight, it should also be ultraviolet ray and ozone resistant or should, after curing, be painted with a compatible coating that provides that resis- tance. The term “sealant“ here is not
36、 limited to mate- rials of adhesive or mastic nature but is inclusive of tapes and combinations of woven fabric strips and mastics. Asphalt based compounds are not recom- mended for sealing ductwork. 3. Unless otherwise prescribed by the equipment man- ufacturer, ducts should be attached to equipmen
37、t with mechanical fastening supplemented with exteri- or duct sealant treatment as defined in paragraph 2. Typical connections are shown in Figure 7. the attachment method should accommodate discon- nection if this is required for routine maintenance of the equipment. -11 - Copyright Air-Conditionin
38、g and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-W 0352320 001078L 318 W 4. Where vibration isolation material is required at the connection of ducts to equipment, such material should be watertight
39、. 5. Roof penetrations by ducts should utilize counter- flashed curbs. Typical arrangements are shown in Figure 8. 6. All penetrations into ducts should be sealed water- tight. Attachment of supports should use a mini- mum number of duct penetrations. 7. Duct systems should not be pressurized withou
40、t suf- ficient time for curing of sealant systems. Follow sealant manufacturers recommendations for applica- tion of the sealant. 8. Adequate clearances between ducts and roof pene- tration openings should be provided. 9. Ducts should be supported to avoid transfer of duct weight across flexible con
41、nections. 1 O. Horizontal ducts should be pitched and provided with drainage outlets as illustrated (by the system design- er). 11. Ducts should be installed at a height sufficient to install roofing and flashing. (See Table 7.) -12- Copyright Air-Conditioning and Refrigeration Institute Provided by
42、 IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m 0352120 0030782 254 m Figure 7 Rooftop Duct Insulation RECTANGULAR DUCT IS SHOWN BUT THE RECOMMENDATIONSAPPLY TO ANY SHAPE AND ORIENTATION d SECTION AA ALERNATE CONNECTION WITH WATERPROOF
43、FLEXIBLE VIBRATION ISOLATION MATERIA- FLANGE, WATERPROOF AND MECHANICALLY FASTEN DUCT TO HVAC UNIT WATERPROOF ALL SEAMS AND JOINTS IN DUCTS ROOF CURB SEE FIG. 8 SUPPORT ATTACHMENT AND REINFORCEMENT ATTACHMENT ELEVATE mTmM OF DucTm MEETTABLE i - 13- Copyright Air-Conditioning and Refrigeration Instit
44、ute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m 0352120 0010783 190 = Figure 8 Duct Penetration of roof SEALANT -. II CCUNTERRASHING CURB -k BASE FLASHING ROOFING PUES -14- t UPPER WCT EXTENDS 3“TO4“BELOW TOPOFWRE Copyrig
45、ht Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-rn 0352120 0010784 o27 m Section D-2 Electrical 1. 2. 3. 4. 5. Whenever possible, electrical conduit should be run to the unit insi
46、de the roof curb. Electrical conduit connections made to exposed junction boxes on units should be made on the bot- tom of the box. Installation should comply with local code requirements. The installation should be made watertight. Where an external electrical junction box is not used, watertight f
47、ittings should be used at the panel joint. If electrical conduit passes through a hole in the panel, that joint should be made watertight. Where electrical conduit passes through the building roof, the construction shown in Figure 9 should be used. Installation should be in accordance with the NFPA
48、I National Electrical Code.” -15- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-0352320 OOL0785 Tb3 = Section D-3 Piping 1. Whenever possible, piping should be brought down through the unit and inside the roof curb. 2. Piping connections made through the side of units not designed to accommodate water entry should be protected by a sheet metal enclosure
