ASHRAE Standards 15 and 34 – Considerations for
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1. E E gt 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Total system refrigerant 410A charge Ibs Example According to Standard 15 minimum allowed floor area is 200 ft if the ceiling height is 10 ft for a non institutional occupancy space that has part of a 52 lbs R410A charge piping circuit installed Formula used for the Diagram Total System Refrigerant Charge Ibs Mi All d Floor A ft x 1000 NMUN AOWERA FIG Area LEGES 1000 FEI ax Celling Height Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 9 of 17 Review refrigerant piping requirements Refrigerant piping location According to Standard 15 Refrigerant Piping must not be less than 7 25ft 2 2m above the floor unless the piping is located against the ceiling and is permitted by the AHJ Refrigerant piping cannot be placed in a shaft containing a moving object and must not be installed in an enclosed public means of egress The wording of the paragraph in Standard 15 says that piping cannot be installed in enclosed stairway landing or means of egress However it also implies that the AHJ could approve installation of the piping above the ceiling as the statement is2. t Office Office A B Occupied space Volume of both rooms Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 12 of 17 Locate the indoor unit fan coil to the plenum above the suspended ceiling One way to be able to include the plenum space above the pi ums Chao suspended ceiling in the room volume calculation is to install an suspended ceiling shall not be indoor unit fan coil above the suspended ceiling and duct it to included in calculating the one or several smaller rooms while drawing un ducted return air refrigerant quantity limit in the through the plenum space above the suspended ceiling See the 9 5 em unless such space is part of the air supply or return system following figure Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Indoor Unit 4 Outdoor Fan Coil Unit ALL Duct TU Suspended adir 1 Ceilin Plenum Office Occupied space Volume of Room and Plenum Remove indoor unit fan coil from system If none of the prescribed actions to increase the room volume can be accomplished one option could be to remove the indoor unit fan coil from the system and install a separate split unit to handle the load in the room Removing the u
3. Occupied t necessarily just one room or an area but can also be space 15 the premises accessible to or several rooms areas that are connected by corridors ductwork occupied by people excluding or other means machinery rooms Reprinted with permission It is recommended to apply the Standard 15 requirements on the CASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 design of a VRV system in 4 basic steps as listed below The checklist at the end of this document can be used to facilitate the steps Preliminary layout of the system Determine the amount of refrigerant Verify that the VRV system layout complies with Standard 15 requirements Actions if a room is too small Preliminary layout of the system The first step in applying Standard 15 in the design process of the VRV system is to develop a preliminary layout of the complete system piping indoor unit fan coil units and outdoor units to meet the heating cooling requirements in the rooms zones of the project Even though the VRV technology allows very long piping distances due to cost and refrigerant charge limitations in ASHRAE Standard 15 the equipment layout should strive to minimize the piping lengths where possible Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information i
4. the right to modify product design specification and information in this document without notice and without incurring any obligation Page 3 of 17 ASHRAE Standard 15 equivalent standards exist in Europe and Asia Systems utilizing the Variable Refrigerant Volume technology are common in these regions and are applied successfully to meet these standards ASHRAE Standards 15 and 34 applied on the VRV technology The ASHRAE Standard 15 was written 1919 Initially it was a Tentative Code and it was recognized as Standard B9 in October 1930 m Originally the Standard was developed for safety following a We e ir 2 catastrophic release of the content in a pressure vessel via numbering refrigerants and safety valve in a short time Over time the scope for the assigning composition designating Standard has been expanded to cover most refrigerants and prefixes for refrigerants Safety systems and 1978 it was issued by ASHRAE as Standard 15 classifications based on toxicity The current version of the Standard does not address the safety m of any particular refrigerant Instead it refers ASHRAE concentration limits for the Standard 34 2010 which identifies safety classifications and refrigerants Refrigerant Concentration Limit RCL for refrigerants Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 34 ANSI ASHRAE Standard 15 2010 Supersedes ANSI ASHRAE Standard 15 2007 Include
5. to protect the piping from being damaged or cause obstruction to an occupant trying to exit the building otandard 15 also states that field installed refrigerant pipe joints must remain exposed for visual inspection before they are covered or enclosed In addition refrigerant piping must be properly supported and if it is installed in concrete floors the piping must be encased in pipe duct Refrigerant monitoring Standard 15 only mentions refrigerant monitoring and alarm functions in case of a leak for refrigerating machinery rooms For occupied spaces refrigerant monitoring should be discussed with the local AHJ Refrigerant piping crossing an open space that affords passageway in any building shall not be less than 7 25ft 2 2m above the floor unless piping is located against the ceiling of such space and is permitted by the AHJ Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Passages shall not be obstructed by refrigerant piping Refrigerant piping shall not be placed in any elevator dumbwaiter or other shaft containing a moving object or in any shaft that has openings to living quarters or to means of egress Refrigerant piping shall not be installed in an enclosed public stairway stair landing or means of egress Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Refrigerant Pipe Joint Inspection Refrigerant pipe joints erected on
6. Voan IKIN AC ASHRAE Standards 15 and 34 Considerations for VRV VRF Systems RESIDENTIAL LIGHT COMMERCIAL COMMERCIAL Technical Article May 2013 ASHRAE Standards 15 and 34 Considerations for VRV VRF Systems Executive Summary The Variable Refrigerant Volume VRV technology was introduced by Daikin in the early 80 s as an alternative method of cooling and heating in commercial buildings Today over 25 million individual spaces are being served by this technology VRV is a very energy efficient and flexible equivalent to a chiller system while it also offers superior comfort compared to traditional air handler terminal units The ASHRAE Standard 15 is significant to HVAC manufacturers engineers and contractors because it specifies compliant design construction installation and operation of refrigeration systems The standard was originally recognized in October 1930 Over time the scope of the standard has been expanded but the features and technology of a VRV system have not been specifically addressed This document demonstrates that e VRV Systems can be properly selected and designed adhering to ASHRAE Safety Standard 15 and Standard 34 e Since Standard 15 is an application based standard not an equipment design guide engineering judgment can be required when applying the standard e tis recommended to use the step by step approach described in this document in order to ensure that the design of a sy
7. ase the refrigerant charge in a single circuit and due to the modularity of the VRV technology the cost per Ton of cooling heating is very similar for several smaller systems or one larger system In the following figure Divided System the larger of the two refrigerant circuits contain 4096 of the total refrigerant charge compared to the previous figures Initial Piping Layout and 48 compared to the Revised Piping Layout Example Divided System 40 of the refrigerant charge for the nitial Piping Layout 4896 of the refrigerant charge for the Revised Piping Layout Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 15 of 17 Additional Information ASHRAE has published a Standard 15 2001 Users Manual ISBN 1931862168 that was developed as a companion document to ASHRAE Standard 15 2001 It does not reflect the addenda and changes incorporated into Standard 15 2004 The User s Manual clarifies the intent of the Standard and provides an explanation of the rationale behind it It eases use of the standard by including illustrations and examples of accepted industry practice as well as explanations of and supporting references for formulas in the Standard This guide also covers building system and refrigerant classi
8. coil is located all rooms that have any part of the refrigerant piping circuit installed should be examined as shown in the following figure Outdoor Indoor Unit Fan Coil _ 4 Smallest room that has any part of the refrigerant piping circuit installed C According to Standard 15 volume calculation shall be based Volume Calculations The volume on the volume of space to which the refrigerant disperses in e o is ri Se 2 UU space lo wnicn rejrigeran case of a leak This Is an important section in Standard 15 and it should be considered if other parts of the Standard do not give refrigerant leak clear enough directions when applying the Standard Reprinted with permission OASHRAE www ashrae org The plenum space above a suspended ceiling can be considered 2010 ANSI ASHRAE Standard 15 a part of the room if it is a part of the air supply or return system Plenums The space above a suspended ceiling When calculating the room volume it is permissible to include the shall not be included in calculating air volume of the supply return ducts connected to fan coil if the he refrigerant quantity limit in the airflow cannot be shut off excludes fire and smoke dampers and system unless such space is part of VAV units if the units cannot shut down to less than 10 96 of l eprinted with permission design airflow with the fan running OASHRAE www a
9. der continuous maintenance by a Standing Standard Project Committne SSPC for which the Standards Com 2010 ASHRAE SSN 1041 2336 rite or tall free 1 800 527 4722 for orders in US and Canada For reprint permission go to ASHRAE SSN 1041 2235 Front cover of ASHRAE Standard 15 2010 is reprinted with permission OASHRAE www ashrae org Front cover of ASHRAE Standard 34 2010 2010 ANSI ASHRAE Standard 15 is reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 34 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 4 of 17 Daikin VRV systems use refrigerant 410A with minimal potential safety risks compared to most other DX type HVAC systems The safety classification of R410A in Standard 34 is group 1 meaning non toxic and non flammable it has no ozone depletion potential and it meets the stringent mandates of both the Montreal Protocol and the U S Environmental Protection Agency However due to the ability to displace oxygen Addendum L to ASHRAE Standard 34 2010 has established the maximum RCL to 26 Ibs 1000 ft of room volume for occupied spaces For Institutional Occupancies the limit is reduced to 50 13 Ibs 1000 f
10. en designing a system Listed equipment containing not more than 6 6 lb 3 kg of refrigerant regardless of its refrigerant safety classification is exempt from Section 7 2 provided the equipment is installed in accordance with the listing and with the manufacturer s installation instructions Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 A high probability system is any system in which the basic design or the location of components is such that a leakage of refrigerant from a failed connection seal or component will enter the occupied space Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 The terms authority having jurisdiction AHJ and jurisdictional authority used herein refer to the organization or individual responsible for enforcing the requirements of this standard Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 5 of 17 Applying Standard 15 when designing a VRV system If refrigerant system piping components and units are located in occupied spaces the spaces must be evaluated regarding safety for the occupants
11. fications restrictions on refrigerant use installation restrictions and equipment and system design and construction The User s Manual includes information on mechanical and absorption refrigeration systems for commercial residential and industrial applications Conclusion A VRV System can be properly selected and designed adhering to ASHRAE Safety Standards 15 and 34 However it is important to keep the following considerations in mind e Standard 15 is an application based standard not an equipment design guide so substantial engineering judgment can be required when applying the standard e Since the indoor unit fan coils are in direct contact with the air being distributed a VRV system is classified as a Direct System according to Standard 15 By definition a Direct oystem is also classified as a High Probability system meaning that a leak of refrigerant can potentially enter into occupied space e ASHRAE Standard 34 2010 has established the maximum Refrigerant Concentration Limit RCL for RA10A to 26 Ibs 1000 ft of room volume for occupied spaces For Institutional Occupancies the limit is 13 Ibs 1000 ft e According to Standard 15 room volume calculation shall be based on the volume of space to which the refrigerant disperses in case of a leak e Many of the attributes of a modern cooling heating technology such as VRV are not addressed in Standard 15 Therefore it is recommended to follow a step by step approach and a
12. he refrigerant openings to the floors served by the system piping passes or Reprinted with permission a e e e piping is located on the exterior wall of a building when ENT if vented to the outdoors or to the space served by the system and not used as an air shaft or similar space Actions if a room is too small If the calculated room volume is too small in relation to the actual refrigerant charge in the system there are generally three different ways to remedy this situation e Increase the room volume used in calculations e Relocate remove piping or indoor unit fan coil e Reduce the refrigerant charge by dividing the refrigerant circuit into multiple smaller systems The checklist at the end of this document can be used to facilitate the possible actions Increase the room volume used in calculations Permanent openings If a room is too small for the amount of refrigerant it might be possible to increase the room volume used in the calculations by connecting it to other rooms Nonconnecting Spaces Where by using louvers transfer grilles door undercuts or similar refrigerating system or a part A permanent opening made to increase the room volume allows thereof is located in or more any leak of refrigerant to disperse into the adjacent area s Wer dE m lt However since Standard 15 does not address how to calculate a MEI BEI permanent opening this sh
13. lso work with the local authority having jurisdiction AHJ when designing a system Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 16 of 17 Checklist Step J Acion J v First Step Preliminary layout of the system EN NN Second Step Determine the amount of refrigerant EN ee ee perder semen man requirements Determine the occupancy classification for the room s Determine room volume s EI Verify that no room is too small Review refrigerant piping requirements Refrigerant piping location 1 1 Refrigerant monitoring Roofand floor piping penetration Fourth Step Actionsifaroomistoosmall Increase the room volume used in calculations EE Permanent openings EE DU Ventilation ZEN Door oo o Remove or raise suspended ceiling mE Relocate remove piping or indoor unit fan coil alode rooms I oM the suspended ceiling S Remove indoor unit fan coil fromsystem S Optimize the piping layout Z Reduce the refrigerant charge by dividing the refrigerant circuit into m
14. n this document without notice and without incurring any obligation Page 6 of 17 Determine the amount of refrigerant The second step is to determine the total amount of refrigerant 410A for the system This calculation can either be done manually according to guidelines in Daikin VRV Installation Manual or by using Daikin VRV Xpress selection software In addition to quickly providing the refrigerant charge the output from VRV Xpress also automatically generates piping and wiring diagrams If piping or indoor unit fan coil locations need to be revised the VRV Xpress will recalculate pipe sizes and refrigerant charge automatically If room has more than one VRV system serving it thus more than one refrigerant circuit installed it is recommended to check with the AHJ regarding how to determine the Quantity of Refrigerant per Occupied Space It is not necessarily the sum of the refrigerant charges in all of the circuits in the room It might be allowed to use the quantity of refrigerant in the largest circuit in the calculations Verify that the VRV system layout complies with Standard 15 requirements The third step is to verify that the initial layout of the VRV system complies with the Standard 15 requirements by Determine the occupancy classification for the room s Determine room volume s Verify that no room is too small Review refrigerant piping requirements The checklist at the end of this document can be used t
15. nit from the system would also lower the total refrigerant charge in the VRV system Optimize the piping layout An alternative or additional remedy is to review the piping layout to see if it can be altered to reduce refrigerant and piping Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 13 of 17 Reduced lengths of the main distribution piping can decrease the refrigerant charge in the circuit considerably In the following figures the Revised Piping Layout lowers the total refrigerant charge in the circuit to 83 of the charge for the Initial Piping Layout Example Revised Piping Layout 83 of the refrigerant charge for the nitial Piping Layout Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 14 of 17 Reduce the refrigerant charge by dividing the refrigerant circuit into multiple smaller systems Depending on system layout size and other factors another option could be to divide the system into multiple smaller and completely separate VRV systems This would dramatically decre
16. not be closed between two rooms should determine the worst case satisfy the requirement of enabling connected spaces Removing 2 leaked refrigerant eprinted with permission the door completely is the safest way to make sure that the Sua TT rooms always are connected 2010 ANSI ASHRAE Standard 15 Remove or raise suspended ceiling Since Standard 15 does allow the space above a suspended ceiling to be used in calculating the room volume if it is a part of the air supply or return system one option could be to remove the ceiling completely Alternatively the suspended ceiling could possibly be raised to a height that provides the required room volume This can be accommodated by using Daikin s indoor unit fan coils that are low profile The height of some of the ceiling units is less than 10 and the height of a slim duct concealed unit is less than 8 Relocate remove piping or indoor unit fan coil Relocate the indoor unit fan coil and duct it to several rooms If none of the actions above are possible for increasing room volume an alternative could be to install the indoor unit fan coil outside the room that is too small By ducting the supply air to several rooms the rooms would be considered connected according to Standard 15 If a leak occurs in the indoor unit fan coil the refrigerant would be dispersed to both rooms as shown in the following figure Indoor Unit Outdoor Fan Coil T d Duct e
17. o facilitate the steps Determine the occupancy classification for the room s The classifications are Institutional occupancy Public assembly occupancy Residential occupancy Commercial occupancy Large mercantile occupancy Institutional occupancy is a Industrial occupancy and Mixed occupancy premise or that portion of a premise from which because they For Institutional occupancies a premise where the occupants oe M IRE P rt conjinea Occupants cannol reaal cannot readily leave without assistance of others the maximum d d P leave without the assistance of refrigerant concentration limit RCL is reduced by 50 compared others Institutional occupancies to the other occupancy classifications include among others hospitals For Industrial occupancies and Refrigerated rooms several nursing homes asylums and special conditions applies see section 7 2 2 in Standard 15 spaces containing locked cells Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 7 of 17 Determine Room volume s Calculate the room volume of the smallest occupied room s In addition to the rooms where each indoor unit fan
18. ould be determined by the Engineer of yore of the smallest occupied record and or the AHJ space shall be used to determine The Japanese standard JRA GL 13 2012 could serve as a the refrigerant quantity limit in the i i i i System guideline regarding the SESS It defines a permanent opening RE as one that has an area of 0 15 o more of the total floor area of CACHE the smaller enclosed occupied space in which refrigerant 2010 ANSI ASHRAE Standard 15 containing parts are located Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 11 of 17 Ventilation When occupied space is served by a mechanical ventilation system the entire air distribution system must be analyzed to determine the worst case distribution yentilated Spaces Where a of leaked refrigerant refrigerating system or a part According to the formal interpretation IC 15 2007 never consider thereof is located within an air increasing the allowable refrigerant limits due to dilution by supply andler in an air distribution duct system or in an occupied space served by a mechanical ventilation and or exhaust air ventilation system the entire air distribution Doors system shall be analyzed to A regular door that can
19. rigeration involving refrigeration systems It strives to ensure a safe systems application of refrigerant systems by limiting the maximum charge This standard applies so that a complete discharge due to a leak into a small occupied to the design construction test and enclosed room can never exceed the allowable limit As with most standards ASHRAE Standard 15 is an application This standard specifies safe inspection of mechanical and absorption refrigeration systems based standard not an equipment design guide so substantial including heat pump systems used engineering judgment can be required when designing a system in stationary applications ASHRAE Standards are part of the National Voluntary Reprinted with permission OASHRAE www ashrae org Consensus Standard In order for a standard to become 2010 ANSVASHRAE Standard 15 mandatory it must first become model building code by an adoption process into the International Mechanical Code IMC Thereafter the model code becomes mandatory when it is adopted at the state or local jurisdiction level Since the conversion from ASHRAE Standard to state local code can take time and parts of the original standard often changes it is recommended to review the local code as well when designing a system Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves
20. s ANSI ASHRAE Addenda listed in Appendix Safety Standard for Refrigeration Systems ANSI ASHRAE Standard 34 2010 Supersedes ANSI ASHRAE Standard 34 2007 Includes ANSUASHRAE Addenda listed in Appendix Designation and Safety Classification of Refrigerants See Appendk for dams by the ASHRAE Standards Committee the ASHRAE Board of Directors and the American National Standards inst This standard i under continuous mainterance by Standing Standard Project ee ich the Standards Com mittee has established a documented program for reguhr publication of addenda or revisions including procedures for e tmely documented conrensus action on requests for charge to any part of the sandard The change submittal form instructione and deadlines may be obtained in electronic form from the ASHRAE website www ashrae org or in paper form from the Standards The h st edition of an ASHRAE Standard may be purchased from the ASHRAE website www ashrae org or ASHRAE Curtomer Service 1791 Tulle Circle NE Athma 20379 2205 E mail ordersshrae org Fax mn o Telephone 404 6 36 8400 workdhwide cc teil free 1 800 527 4723 for orders in US and Canada For reprint permission go to www athrae org permissions ln 9 ory ende forapproval dates by the ASHRAE Standards Committee the ASHRAE Board of Directors and the American Standards Institute ndard amp un
21. shrae org 2010 ANSI ASHRAE Standard 15 Supply and Return Ducts The volume of the supply and return ducts and plenums shall be included when calculating the refrigerant quantity limit in the system Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 8 of 17 Verify that no room is too small Using the calculated total refrigerant charge verify that there are no rooms that have a part of the refrigeration circuit installed that has a smaller calculated room size than shown in the following Diagram If a room is verified to be too small according to the Diagram review the section Fourth Step Actions if a room is too small in this document 10 ft Ceiling Height RCL 13 Ibs 1000 3 Institutional Occupancy 8 ft Ceiling Height Z RCL 26 10 1000 3 10 ft Height L RCL 26 Ibs 1000 ft 12 ft Ceiling Height RCL 26 lbs 1000 2 14 ft ft Ceiling Height lt RCL 26 Ibs 1000 fe QN 4 Q o v Ln Gg ed OU 3 O 5 5 jen o c G 5 lt 9 O
22. stem follows Standards 15 and 34 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 2 of 17 Introduction VRV Technology In the early 1980s the Variable Refrigerant Volume VRV technology was introduced by Daikin as an alternative method of cooling and heating in commercial buildings Although VRV has been commercially available globally for over 30 years it remains a relatively new concept to the North American market VRV is an applied heating and cooling system that distributes refrigerant rather than water to multiple fan coil units serving the conditioned spaces The natural attributes of a VRV system position it as a modular and scalable energy saving equivalent to a chiller system while offering superior comfort when compared to traditional air handler terminal units The compact lightweight structure within the VRV modular concept ensures ease of installation in small or large buildings ASHRAE Standard 15 The ASHRAE Standard 15 2010 provides safeguards for life limb health property and prescribes safety requirements The standard is recognized by equipment manufacturers design construction installation engineers and contractors as the main guide for personal safety and operation of ref
23. t refrigerant concentration limit RCL the refrigerant concentration limit in air determined in accordance with this standard and intended to reduce the risks of acute toxicity asphyxiation and flammability hazards in normally occupied enclosed spaces Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 34 For smaller systems with less than 6 6 lbs of total refrigerant charge the 26 Ibs 1000 ft limit described above does not apply regardless of refrigerant safety classification if the system is installed according to the listing and manufacturer s instructions oince the indoor unit fan coils are in direct contact with the air being distributed a VRV system is classified as a Direct System according to Standard 15 By definition a Direct System is also classified as a High Probability system meaning that a leak of refrigerant can potentially enter into occupied space The information in this document is intended to provide guidance to specifying and designing a VRV system while applying ASHRAE safety Standard 15 However since many of the attributes of a modern cooling heating technology such as VRV are not specifically addressed in Standard 15 there might be variations in how the authority having jurisdiction AHJ interprets compliance requirements to Standard 15 between jurisdictions Therefore it is good practice to review the local code and work with the local AHJ wh
24. the premises shall be exposed to view for visual inspection prior to being covered or enclosed Refrigerant piping installed in concrete floors shall be encased in pipe duct Refrigerant piping shall be properly isolated and supported to prevent damaging vibration stress or corrosion Reprinted with permission OASHRAE www ashrae org 2010 ANSI ASHRAE Standard 15 Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation Page 10 of 17 Roof and floor piping penetration A VRV system is classified as a direct system and it must always be designed according to the leakage concentration limits in ASHRAE Standard 34 Therefore the penetration restriction in Section 8 10 3 in Standard 15 does d penetrate floors ceiling or roofs not apply for VRV if the system is designed correctly and the Exceptions RCL is within the stated limits d Penetrations of a direct system Also if the RCL is above the stated limits in a non industrial where refrigerant concentration does not exceed that listed in Table occupancy application the penetration restriction does not apply jf 1 or 2 of ASHRAE Standard 34 for the smallest occupied space e piping is enclosed by an approved duct shaft with through which t
25. ultiple smaller systems Disclaimer The information contained herein is provided for general guidance and informational purposes only and is not a substitute for complying with all national state and local codes as may be required Every HVAC installation varies in its individual circumstances and the local authorized engineer and or installer will have to use their professional judgment in each installation for code compliance The contents herein are NOT approved by ASHRAE and do not imply an ASHRAE endorsement per ASHRAE s Policy Published by the Daikin Product Marketing Department Daikin s products are subject to continuous improvements Daikin reserves the right to modify product design specification and information in this document without notice and without incurring any obligation TAVRVUSE13 05C Page 17 of 17
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