ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc. 1791 Tullie Circle, NE • Atlanta, Georgia 30329-2305 404-636-8400 • Fax 404-321-5478 SPC/GPC MINUTES COVER SHEET (Minutes of all SPC/GPC Meetings are to be distributed to all persons listed below within 60 days following the meeting.) SPC/GPC NO.: ISSUE DATE: SSPC 15 SPC/GPC TITLE: DATE OF MEETING: August 23, 2007 Safety Standard for Refrigeration Systems LOCATION: Long Beach, CA June 24, 2007 Attendance Voting Members Present Status Others Present Status Douglas T. Reindl Stephen W. Duda Ajay R. Chatlani Dennis R. Dorman Danny M. Halel Jay A. Kohler Eugene Troy PCVM – Chair PCVM – Secretary PCVM PCVM PCVM PCVM PCVM Voting Members Absent Status James M. Calm Martin L. Timm PCVM PCVM Bruce Griffith Wayne Borrowman Bill Tritsis Michael Hossler Claude Wilkinson John Vucci John Sluga Kirsten McNeil Carl Radcliffe Jeff Berge Doran Shapiro Bill Mohs Kyle Wessells Umar Khokhar Robert Richard Jim Crawford Guest Guest Guest Guest NVM, Webmaster Guest Guest Guest Guest Guest Guest Guest Guest Guest Guest Guest DISTRIBUTION: ALL MEMBERS OF SSPC 15 LIAISONS: SPLS: Steve Bushby Staff: Mark Weber -1These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. Meeting Summary Action Items (carried forward from previous Meetings): 06A-01. 06A-02. 06A-03. 06A-04. 06A-05. Status: Status: Status: Status: Status: Complete / Closed Complete / Closed Complete / Closed Complete / Closed Complete / Closed 06A-06. Responsible Party: D. Reindl, M. Timm, G. Troy Action: Resolve 15-2004 Addendum ‘a’ two Public Review Comments. Two comments received during the Public Review of this CM Change Proposal; both are unresolved. Proposed resolution for one commenter: “Consideration must be given to hydrostatic expansion due to temperature rise of liquid refrigerant trapped in or between closed valves. A hydrostatic relief device or other means shall be provided to prevent over-pressurization. Relief into a lower pressure portion of the system is allowed. Relief to atmosphere is also allowed if the requirements of 9.7.8 are met. The use of hydrostatic relief devices for A2, B2, A3, and B3 refrigerants relieving directly to atmosphere is prohibited.” No proposed resolution yet for second commenter. Status: Ad-hoc subcommittee working toward completion by 2008 Winter Meeting. 06A-07. 06A-08. 06A-09. 06A-10. 06A-11. 06A-12. 06A-13. Status: Status: Status: Status: Status: Status: Status: Complete / Closed Complete / Closed Complete / Closed Complete / Closed Complete / Closed Complete / Closed Complete / Closed 07W-01. Responsible Party: D. Reindl Action: Obtain letter ballot from absent member Calm re: Shall the committee Approve for Publication Public Review Dorman CM Change Proposal #15-07-12-0001 with two Amendments: (1) Reword the proposed language of Paragraph 7.2 to read “The concentration of refrigerant in a complete discharge of each individual independent circuit . . . ” and (2) Update and/or substitute the latest Tables Std. 34 Addendum v subject to their publication, in lieu of the Table in the Change Proposal. Status: Calm refused a response; Reindl will pursue further. 07W-02. Responsible Party: M. Timm, C. Radcliffe, J. Kohler Action: Further refine and develop Kohler CM Change Proposal #15-06-12-0002. Consider the possibility that some form of containment may be required; and whether the Proposal as written could allow the release of live steam. Status: In progress at this meeting; work continues. -2These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. 07W-03. Responsible Party: D. Reindl Action: Return Domina CM Change Proposal #15-06-12-0001 marked “Accepted for further study.” Status: Complete. 07W-04. Responsible Party: S. Duda, D. Dorman, J. Vucci, M. Timm and the Proposer Action: Further study Domina CM Change Proposal #15-06-12-0001 to evaluate its possible merits. M. Timm offered to run release dispersion computer models. Status: In progress at this meeting; work continues. 07W-05. Responsible Party: M. Timm Action: Be prepared to discuss revisions to Article 9.2 of the Standard. Status: Complete. 07W-06. Responsible Party: D. Halel Action: Further study McClure CM Change Proposal #15-05-12-0004-002; solicit comments from TC 03.08, refrigerant leak detector manufacturers, and perhaps others. Status: In progress at this meeting; work continues. 07W-07. Responsible Party: D. Reindl Action: Obtain letter ballot from absent member Calm re: Shall the committee Approve for Publication Public Review Radcliffe CM Change Proposal #15-05-12-0002 as amended to read “Hermetic refrigerant motor-compressors that are listed and have a displacement less than or equal to 50 ft3/min.” Status: Complete. Becomes Addendum b to 15-2007. 07W-08. Responsible Party: M. Timm, C. Rohrer Action: Study, consider, and submit Bienvenu’s Interpretation Request as a CM Change Proposal instead of an Interpretation. Status: Complete. -3These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. Action Items (new this Meeting): 07A-01. Responsible Party: D. Reindl. Action: Reindl to distribute a *.pdf copy of the Standard 15-2007 for official committee use. Due Date: Completed. 07A-02. Responsible Party: D. Reindl. Action: Chair will to obtain Letter Ballot from two absent members prior to the July 1, 2007 Roster for Motions 2, 3, and 4. Due Date: Completed. 07A-03. Responsible Party: D. Reindl and M. Timm. Action: Refine and complete work on Timm Change Proposal 15-07-12-0003/002 (classification of cascades systems). Due Date: 2008 Winter Meeting. 07A-04. Responsible Party: D. Reindl, S. Duda, M. Timm. Action: With respect to Domina Change Proposal 15-06-12-0001 (Revise 15’ clause of 9.7.8), perform PHAST modeling to confirm ground level, 20’ and 15’ refrigerant dispersion figures. Variables to be considered include Stability Class Type C and F; quiet air and moving air; free area versus a wall or obstruction. Request concentration in bands. Due Date: 2008 Winter Meeting. 07A-05. Responsible Party: J. Kohler and D. Dorman Action: With respect to Domina Change Proposal 15-06-12-0001 (Revise 15’ clause of 9.7.8), research typical mass flow rates of relief discharge for outdoor air-cooled chillers, for R-134a. Consider different relief rates; B1 refrigerants; a differentiation between large and smaller machines. Due Date: As soon as possible; this is a prerequisite for Action Item 07A-04. 07A-06. Responsible Party: G. Zyhowski. Action: With respect to McClure Change Proposal 15-05-12-0004-001 (removal of refrigerant vapor), obtain some modeling-based research analysis to justify proposed resolution. Due Date: 2008 Winter Meeting. -4These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. SUMMARY OF MOTIONS: Secretary’s Note: All votes recorded herein are formatted as Aye-Nay-Abstain-Absent. Chair voted unless noted otherwise. 1. Motion: Second: Text: Vote: 2. Motion: Second: Text: Vote: 3. Motion: Second: Text: Vote: 4. Motion: Second: Text: Vote: S. Duda D. Dorman Approve the Dallas January 27, 2007 Winter Meeting Minutes as written. Motion Carried 7-0-0-2. D. Halel E. Troy Approve for Publication Public Review the Timm Change Proposal 15-07-12-0003/001 as written. Motion Carried 7-0-0-2 with Letter Ballot required to absent members. D. Halel S. Duda Approve for Publication Public Review the Timm Change Proposal 15-07-12-0003/003 as amended in Attachment F. Motion Carried (6-0-1-2) with Letter Ballot required to absent members. D. Dorman was the abstainer and offered the reason: It needs further refinement; that he understands the desire to expedite this Change Proposal but feels we are moving too quickly and “on the fly”. D. Halel J. Kohler Approve for Publication Public Review the Reindl Change Proposal 15-07-12-0004/001 as amended in Attachment F. Motion Carried 7-0-0-2 with Letter Ballot required to absent members. -5These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. MINUTES I. Call to Order a) Call to Order - Doug Reindl, Chairman, called the meeting to order at 1:04 pm the Hyatt Regency Ballroom F in Long Beach, CA. Seven Voting members (of Nine) were in attendance, thereby constituting a quorum. II. Introduction of Members And Guests a) Self-introductions of members and guests were made around the table as the attendance roster was circulated. Reindl welcomed all guests and visitors. A quorum was verified. III. Approval of Dallas January 28, 2007 Winter Meeting Minutes a) Stephen Duda offered a MOTION to approve the Dallas January 28, 2007 Winter Meeting Minutes as written. Dennis Dorman offered a Second. No corrections nor further discussion. Show-of-Hands Vote: Motion Carried (7-0-0-2). Secretary’s Note: All votes recorded herein are formatted as (Aye-Nay-Abstain-Absent); Chair voting unless noted otherwise. IV. Summary of PC Chair’s Breakfast a) Reasons for negative or abstaining votes must be recorded when voting for publication or public review. b) Failure to attend two consecutive meetings (or failure to respond to at least 60% of letter ballots) is grounds for removal from an SPC/SSPC. c) It was requested that Reindl distribute a *.pdf copy of the Standard 15-2007 for official committee use. ACTION ITEM #07A-01. V. Roster Update a) Jay Kohler and Gene Troy have been added to the Roster as of 2.01.2007. b) Duda was formally appointed Secretary of this committee as of 2.01.2007. c) Membership invitation was extended by Reindl to guests and interested parties. VI. Liaison reports (Liaisons) a) CIS – (Phil Johnson / Daryl Showalter): Absent / No Report. b) Std. 34 – (Kohler): 2007 Edition of Standard 34 was published and is available from ASHRAE. c) Refrigeration Committee – (Bruce Griffith): Reported some movement toward a Handbook Chapter and technical guidance for CO2 as a refrigerant. d) TC 09.01 – (Duda). Duda reported on the status of Research #WS-1448 on Machinery Room Ventilation rates. Steve Taylor had previously agreed to take the lead on writing this Work Statement but has not had time to do so. Duda will assist Taylor to help expedite this item. e) No other reports were given. -6- These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. VII. Review of Action Items from Dallas (Reindl) a) The committee reviewed each Action Item from the previous meetings. See status report included herewith. VIII. Standard 15-2007 Addenda (Reindl) a) Addendum a to the 2007 Edition – (Duda) Refer to Attachment A; has cleared this committee and Publication Public Review, and is expected to be presented for final approval to the Standards Committee and Board of Directors at this Society Meeting. b) Addendum b to the 2007 Edition – (C. Radcliffe) Refer to Attachment B; has cleared this committee and Publication Public Review, and is expected to be presented for final approval to the Standards Committee and Board of Directors at this Society Meeting. IX. CM Change Request Update a) Dorman – 15-07-12-0001 (ASHRAE 34 Addendum u-related changes) – Refer to Attachment C. Jim Calm has objections over failure to address volatility in the RCL. Some refrigerants exist as a liquid at common conditions and therefore do not have any concentration in air. Kohler/Dorman both comment that all we are trying to do is update our Standard to incorporate recent changes to Std 34; nothing more. Counterpoint from Calm is that this issue keeps getting swept aside and needs action to be addressed. Chair in consensus with those present decided that, since this Change Proposal has formally been approved by SSPC 15 with the necessary supermajority at a previous meeting, it will be issued for Publication Public Review with Calm’s negative vote duly noted. Secretary’s Post-Meeting Note: This Item has been superseded by subsequent Letter Ballot action during the month of August 2007. b) Kohler – 15-06-12-0002 (Relief venting for R-718) – Refer to Attachment D. Kohler provided an oral summary. Worked diligently but did not make significant progress toward agreement. Item carries forward. c) Martin Timm – 15-07-12-0003/001-003 (R-744 related) – Presented by Reindl in Timm’s absence. Refer to Attachment E for Timm’s Change Proposal. Refer to Attachment F for Reindl’s presentation and discussion of same. Background: CO2 is being used more commonly in subcritical and transcritical applications. It has a high Personnel Exposure Limit (PEL), is not flammable, is natural, and is a desirable refrigerant over a very specific range of conditions. Critical Point is 1070 psia and 87.8°F. Reindl reviewed the cascade system and gave these Change Proposals context. Example: Grocery refrigeration sometimes applies a cascade system of ammonia to CO2, used to obtain the benefits of ammonia refrigeration without exposing occupants to risk at the end point of use. Standard 15 does not effectively establish a context for use of CO2. Hence this CM Change Proposal is submitted, to allow more realistic conditions for CO2 in cascade or secondary coolant applications. Danny Halel offered a MOTION to approve for Publication Public Review the Timm Change Proposal 15-0712-0003/001 (adds three definitions) as written. Troy offered a Second. Show-of-Hands Vote: Motion Carried (7-0-0-2). Chair will to obtain Letter Ballot from two absent members prior to the July 1, 2007 Roster Change. ACTION ITEM #07A-02. Timm Change Proposal 15-07-12-0003/002 (classification of cascades systems) was tabled for additional subcommittee work. ACTION ITEM #07A-03. Discussion of Timm Change Proposal 15-07-12-0003/003 (relief device sizing): -7- These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. Duda: What is the rational for 500 psia? Response: Somewhat arbitrary but allows some safety over expected conditions, and to avoid excessive venting; a balance between practical and safe. The definitions given in Timm Change Proposal 15-07-12-0003/003 are believed to be consistent with ASHRAE terminology. Amendment to Change Proposal 15-07-12-0003/003: Non-technical editing of each instance of the words “is to be” are amended to read “shall be.” A confirming copy of the Change Proposal as amended is found in Attachment F. Halel offered a MOTION to approve for Publication Public Review the Timm Change Proposal 15-07-120003/003 as amended immediately above. Duda offered a Second. Show-of-Hands Vote: Motion Carried (60-1-2). Dorman was the abstainer and offered the reason: It needs further refinement; that he understands the desire to expedite this Change Proposal but feels we are moving too quickly and “on the fly”. Chair will obtain Letter Ballot from two absent members prior to the July 1, 2007 Roster Change. ACTION ITEM #07A-02. d) Reindl – Change Proposal 15-07-12-0004/001 (R-744 design pressures) – Refer to Attachment E for Reindl’s Change Proposal. Refer to Attachment F for Reindl’s presentation and discussion of same.. Discussion: Does this conflict with ASME? No; this helps define the operating pressure. Dorman: What problem are you trying to solve? Response: Mostly the 1000+ psia requirement, which is simply not practical. Discussion related to intentional venting (either as normal course, or in the event of a power failure to avoid overpressurization) of CO2 and does this present a problem with the EPA. General discussion that this CM Change Proposal seems to be sufficiently conservative. The term “maximum operating conditions” was questioned by Kohler as perhaps not clearly defined. Language was simplified and some text was trimmed. Amendments to Change Proposal 15-07-12-0004/001: The entire Change Proposal language was substituted as follows: Revise the proposed new Section 9.2.6 to now read “9.2.6 When a refrigerating system utilizes carbon dioxide (R744) as a secondary coolant, or as a refrigerant in a cascade refrigerating system, the system design pressure of the R744 containing components shall be not less than the higher of a) or b). a) 500 psig or b) 25% higher than the saturation pressure at its warmest location in the circuit under maximum operating conditions A confirming copy of the Change Proposal as amended is found in Attachment F. Halel offered a MOTION to approve for Publication Public Review the Reindl Change Proposal 15-07-120004/001 as amended above. Kohler offered a Second. Show-of-Hands Vote: Motion Carried (7-0-0-2). Chair will obtain Letter Ballot from two absent members prior to the July 1, 2007 Roster Change. ACTION ITEM #07A-02. e) Reindl – 15-07-12-0004/002 (Hydrostatic Relief) – Reported that the subcommittee is still working through the issues and have not yet achieved agreement at the subcommittee level. -8These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. f) Domina – 15-06-12-0001 (Revise 15’ clause of 9.7.8) (Duda) – Refer to Attachment G. Duda reported on work of subcommittee as follows: Duda led a review of Paragraph 9.7.8. and possible re-write in subcommittee, which was presented to the full committee and is included as Attachment H. The term “Controlled Access” requires definition. John Vucci presented a case study of several refrigerant relief installations on the campus of the University of Maryland. Refer to Attachment I. Dorman suggested that modeling should be performed to confirm or alter the 15’ discharge clause of 9.7.8. Duda and Reindl will recruit Timm to perform PHAST modeling to confirm ground level, 20’ and 15’ refrigerant dispersion numbers. Variables to be considered include Stability Class Type C and F; quiet air and moving air; free area versus a wall or obstruction. Request concentration in bands. ACTION ITEM #07A04. In addition to the above, we need to define a mass flow rate of discharge.. Kohler/Dorman will research typical relief on typical outdoor air-cooled chillers, for R-134a. Their work will consider different relief rates; B1 refrigerants; a differentiation between large and smaller machines. ACTION ITEM #07A-05. Item carries forward to the next Meeting. g) McClure 15-05-12-0004-001 (removal of refrigerant vapor) (G. Zyhowski): Refer to Attachment J. In process. Zyhowski not present but intends to obtain some modeling-based research analysis. Item carries forward to the next meeting. ACTION ITEM #07A-06. h) McClure 15-05-12-0004-002 (refrigerant detectors) (Halel): Refer to Attachment K. Reviewed in committee. Consensus agreement that specification of infrared (or any other) specific technology is not appropriate in a Standard. The Standard can define performance and testing requirements, but not any specific technology. Perhaps the committee should obtain input from leak detector manufacturers, and work is still needed in establishing performance criteria. ACTION ITEM #07W-06. X. Interpretation Requests a) Several informal requests were received processed since the previous meeting. There are no formal Interpretation Requests pending. XI. Update on related standards a) IIAR-2 (Troy): Second public review draft has been issued. b) ISO 5149 (Kohler) Report on subcommittee meeting earlier today. The minutes of the ISO 5149 subcommittee meeting are included herewith as Attachment L. c) UL (Radcliffe) 1995: This organization is currently reconciling UL 1995 with international documents. XII. Other Business a) None. -9These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. XIII. Adjournment a) Next Meeting: Sunday, January 20, 2008 at 1:00 pm EST in New York, NY. b) Chairman Reindl declared the meeting adjourned at 5:10 pm local time. End of Minutes Respectfully submitted by: Stephen W. Duda Secretary of SSPC 15 - 10 These Minutes were approved by vote of this Committee on January 20, 2008 and are the official, approved record of the proceedings. ATTACHMENT ‘A’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS, INC. FORM FOR RESPONSE TO CHANGE PROPOSAL DATE January 31, 2006 PROPOSAL NUMBER: Duda 15-05-12-0003 SSPC NO. 15 RESPONDER'S NAME __Steven Duda_____________________________________________________ ADDRESS __Ross & Baruzzini ________________________________________________ __#6 South Old Orchard ___________________________________________ __St. Louis, MO 63119 _______________________________________ TELEPHONE __(314) 918-8383 _________ FAX __(314) 918-1766 __________________________ Proposal Number(s) _________15-05-12-2003____________________________________________________________ _____________________________________________________________________________________________ Project Committee Action: Proposed change accepted for public review without modification XXX Proposed change accepted for publication public review with modification (See below) Proposed change accepted for further study (See below) Proposed changed rejected (See below) More information is needed (See below) Project Committee Response: The Project Committee accepts the referenced change proposal with respect to technical meaning but modifies the change proposal’s written format as follows: Revise Paragraph 9.7.8 to read as follows: 9.7.8 Pressure-relief devices and fusible plugs on any system containing a Group A3 or B3 refrigerant; on any system containing more than 6.6 lb (3 kg) of a Group A2, B1, or B2 refrigerant; and on any system containing more than 110 lb (50 kg) of a Group A1 refrigerant For systems in which any one or more of the following conditions apply, pressure relief devices and fusible plugs shall discharge to the atmosphere at a location not less than 15 ft (4.57 m) above the adjoining ground level and not less than 20 ft (6.1 m) from any window, ventilation opening, or exit in any building: (a) Any system containing a Group A3 or B3 refrigerant. January 16, 2002 (b) Any system containing more than 6.6 lb (3 kg) of a Group A2, B1, or B2 refrigerant. (c) Any system containing more than 110 lb (50 kg) of a Group A1 refrigerant. (d) Any system for which a Machinery Room is required by the provisions of 7.4 The discharge shall be terminated in a manner that will prevent the discharged refrigerant from being sprayed directly on personnel in the vicinity and foreign material or debris from entering the discharge piping. Discharge piping connected to the discharge side of a fusible plug or rupture member shall have provisions to prevent plugging the pipe in the event the fusible plug or rupture member functions. cc: Manager of Standards, ASHRAE, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305 January 16, 2002 ATTACHMENT ‘B’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. BSR/ASHRAE Addendum b to ANSI/ASHRAE Standard 15-2007 Public Review Draft _____________________________________ ASHRAE Standard Proposed Addendum b to Standard 15-2007, Safety Standard for Refrigeration Systems First Public Review (March 2007) (Draft Shows Proposed Changes to Current Standard) This draft has been recommended for public review by the responsible project committee. To submit a comment on this proposed addendum, use the comment form and instructions provided with this draft. The draft is subject to modification until it is approved for publication by the Board of Directors and ANSI. Until this time, the current edition of the standard (as modified by any published addenda on the ASHRAE web site) remains in effect. The current edition of any standard may be purchased from the ASHRAE Bookstore @ http://www/ashrae.org or by calling 404636-8400 or 1-800-527-4723 (for orders in the U.S. or Canada). This standard is under continuous maintenance. To propose a change to the current standard, use the change submittal form available on the ASHRAE web site @ http://www/ashrae.org. The appearance of any technical data or editorial material in this public review document does not constitute endorsement, warranty, or guaranty by ASHRAE of any product, service, process, procedure, or design, and ASHRAE expressly disclaims such. © February 13, 2006. This draft is covered under ASHRAE copyright. Permission to reproduce or redistribute all or any part of this document must be obtained from the ASHRAE Manager of Standards, 1791 Tullie Circle, NE, Atlanta, GA 30329. Phone: 404-6368400, Ext. 1125. Fax: 404-321-5478. E-mail: [email protected]. AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS, INC. 1791 Tullie Circle, NE Atlanta GA 30329-2305 BSR/ASHRAE Addendum b to ANSI/ASHRAE Standard 15-2007, Safety Standard for Refrigeration Systems First Public Review Draft (This foreword is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been processed according to the ANSI requirements for a standard and may contain material that has not been subject to public review or a consensus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.) Foreword The current version of ANSI/ASHRAE Standard 15-2007 requires pressure relief protection for all positive displacement compressors, regardless of size. The proposed change will bring Standard 15 in to alignment with UL 984 (Hermetic Refrigerant-Motor Compressors) and except small compressors due to their self-limiting nature in building excessive discharge pressure if started while isolated. Note: In this addendum, changes to the current standard are indicated in the text by underlining (for additions) and strikethrough (for deletions) unless the instructions specifically mention some other means of indicating the changes. Only these changes are open for review and comment at this time. Additional material is provided for context only and is not open for comment except as it relates to the proposed substantive changes. Addendum b to 15-2007 Revise Paragraph 9.8 to read as follows: 9.8 Positive Displacement Compressor Protection. When equipped with a stop valve in the discharge connection, every positive displacement compressor shall be equipped with a pressure-relief device of adequate size and pressure setting, as specified by the compressor manufacturer, to prevent rupture of the compressor or to prevent the pressure from increasing to more than 10% above the maximum allowable working pressure of any other component located in the discharge line between the compressor and the stop valve or in accordance with 9.7.5, whichever is larger. The pressure-relief device shall discharge into the low-pressure side of the system or in accordance with 9.7.8. Exception: Hermetic refrigerant motor-compressors that are listed and have a displacement less than or equal to 50 ft3/min ( 1.42 m3/min). 9.8.1 The relief device(s) shall be sized based on compressor flow at the following conditions: 1. High-Stage or Single-Stage Compressors: Flow is to be calculated based on 50°F (10°C) saturated suction temperature at the compressor suction. 2. Low-Stage or Booster Compressors: For those compressors that are capable of running only when discharging to the suction of a high-stage compressor, flow is to be calculated based on the saturated suction temperature equal to the design operating intermediate temperature. Exception for items 1 and 2: The discharge capacity of the relief device is allowed to be the minimum regulated flow rate of the compressor when the following conditions are met: (a) the compressor is equipped with capacity regulation, (b) capacity regulation actuates to minimum flow at 90% of the pressure-relief device setting, and (c) a pressure-limiting device is installed and set in accordance with the requirements of 9.9. Appendix F describes one acceptable method of calculating the discharge capacity of positive displacement compressor relief devices. ATTACHMENT ‘C’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ATTACHMENT ‘D’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ATTACHMENT ‘E’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ATTACHMENT ‘F’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. SSPC 15 CM Change Proposals 15-07-12-0003/001-003 – Timm 15-07-12-0004/001 – Reindl Background Carbon dioxide is increasingly finding use in refrigeration applications Subcritical pressures Supermarket refrigeration systems Industrial refrigeration systems Transcritical MAC Unitary Carbon Dioxide Characteristics Colorless Odorless Non-flammable Natural refrigerant Essentially, non-reactive and non-toxic PEL = 5,000 ppm Desirable properties as a refrigerant (over a limited range) Carbon Dioxide Phase Diagram Pcrit = 1070 psia Tcrit = 87.8°F NH3-CO2 Cascade System Tdischarge,sat=+30oC [+86oF] Pdischarge=169 psia -15 oC [+5 oF] R717 Tsuction,sat=-18oC [+0oF] NH3 compressor Psuction=30 psia Tdischarge,sat=-12oC [+10oF] Pdischarge=360 psia Cascade HX CO2 compressor Tsuction,sat =-40oC [-40oF] Psuction=145 psia CO2 - receiver CO2 CO2-evaporator Tevap,sat =-40oC [-40oF] Pevap=145 psia Adapted from Halsey 2007 CO2 System in Sam’s Club (Savanna, GA) That sounds great – what’s the problem? Standard 15-2007 Currently does not have definitions that effectively establish a context for these systems and their safety design requirements The current design pressure requirements are not consistent with how these systems are designed and operated 15-07-12-0003/001 Add the following definitions: Cascade refrigerating system: One having two or more refrigerant circuits, each with a pressure imposing element, condenser, and evaporator, where the evaporator of one circuit cools the condenser of another (lower temperature) circuit. Compound refrigerating system: A multi-staged refrigerating system where a single charge of refrigerant circulates through all stages of compression. Multistage refrigerating system: System in which compression of refrigerant is carried out in two or more steps. 15-07-12-0003/002 15-07-12-0003/003 15-07-12-0004/001 15-07-12-0004/001 Add the following new section as 9.2.6: 9.2.6 When a refrigerating system utilizes carbon dioxide (R744) as a secondary coolant, or as a refrigerant in a cascade refrigerating system, the system design pressure of the R744 containing components shall be not less than the higher of a or b. a. 500 psig or b.25% higher than the saturation pressure at its warmest location in the circuit under maximum operating conditions ATTACHMENT ‘G’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS, INC. FORM FOR RESPONSE TO CHANGE PROPOSAL DATE ___January 28, 2007______ SSPC NO. : _15________ PROPOSAL NUMBER(S): ___15-06-12-0001-001_________________________ RESPONDER'S NAME: __Douglas T. Reindl__________________________________________________ ADDRESS: __432 North Lake St_________________________________________________ __Madison, WI 53706 USA__________________________________________ ___________________________________________________________________ TELEPHONE: _(608) 262-6381___________ FAX: __(608) 262-6209____________________ Proposed change accepted for public review without modification Project Committee Action: Proposed change accepted for public review with modification (See below) X Proposed change accepted for further study (See below) Proposed changed rejected (See below) CM Proposal: The following changes are proposed: Insert the following between 9.7.8 and 9.7.8.1: Exemption: Pressure relief devices and fusible plugs may discharge at a location below the 15 ft height specified above provided that all the following conditions are true and the other requirements of 9.7.8 are met: • • • The refrigerant is classified in Group A1 in Table 1. The system location meets the criteria for “Industrial Occupancy” or “Commercial Occupancy” where the relief discharge is located at least 20 ft from the nearest pedestrian walkway and is within an access controlled area (e.g. fenced area, on a roof, etc.) The system is located outdoors and that the formation of an oxygen deficient atmosphere is not credible. The author of the proposed change notes a competing concern with metal fatigue on the relief vent line as a result of equipment vibration and cantilevered loads due to the weight of the vent tail pipe (particularly for piping larger than 1 inch and with screwed connections). Furthermore, the author expressed concerns over the possibility of rainwater and condensation infiltrating the vent piping and potentially corroding relief valve springs. In summary, the proposed change is intended to preserve safety and enhance mechanical integrity. Revised: 7.5.2006 Project Committee Response: A subcommittee has been formed to study this further and, potentially, develop alternative provisions to accommodate these situations. cc: Manager of Standards, ASHRAE, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305 Revised: 7.5.2006 ATTACHMENT ‘H’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. PROPOSED RE-WRITE OF PARAGRAPH 9.7.8 IN RESPONSE TO DOMINA CM CHANGE PROPOSAL 15-16-12-0001 SSPC 15 AD-HOC SUBCOMMITTEE MEETING JUNE 23, 2007 @ Noon in Long Beach, CA Exemption Exception: Pressure relief devices and fusible plugs may discharge at a location below the 15 ft height specified above provided that all the following are true and the other requirements of 9.7.8 are met: The refrigerant is classified as Group A1 in Table 1. The system location meets the criteria for “Industrial Occupancy” or “Commercial Occupancy” where the relief discharge is located at least 20 ft from the nearest pedestrian walkway and is within an access-controlled area (e.g., fenced area, on a roof, etc.) restricting pedestrian access to a distance of 20 feet (6.1 m) or more in all directions from the termination point. The system is located outdoors and that the formation of an oxygen deficient atmosphere is not credible. The point of discharge shall be above grade, at a height and location not subject to weather (e.g., snow accumulation) and/or physical obstructions. ATTACHMENT ‘I’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. Refrigerant Package Chillers & Dx systems Picture Overview • You asked me to take several pictures of installations at the University of Maryland to so how packaged chillers are field installed typically. • The request was made at the Dallas meeting responding to some members sympathy towards real world application issues of the Standard 15. I indicated that I to at the University do not require on packaged chillers the requirement to pipe refrigerant relief piping in accordance with the Standard 15. • The requester I believe requested an interpretation where a packaged chiller is installed on grade, I believe, and is securely fenced in with security, the refrigerant piping discharge to above the chiller is not required. Refrigerant Package Chillers & Dx systems Picture Overview • • The pictures within are either installed by the University of Maryland directly (HVAC Systems Unit) or by contractors in typical bid specification situations. Most new systems installed in the last 7 years have had direct input by me regarding the specifications including adherence to ASHRAE standards. Also, I as the cognizant authority for HVAC systems have allowed not compliance with certain systems where the interests of the University are conflicting so long as no direct correlation to life and safety can be identified. Pictures are of a 150 TR packaged water chiller (R-22) installed circa 2003. Enclosure exists around unit shown as part of historic wall foreground and building with new fencing with locked gate for qualified access. University has secure Mechanical key issued to personnel. Additionally within enclosure is a smaller package system installed noted in the picture. The smaller unit sits about 8 feet from the larger unit. No relief piping installed. Open Window Zoned Dx condenser (R-22), installed 2003, along with several ductless Dx package condensing units (R-22 and R-410a), installed 2004-2006, along corner of facility. No relief piping or secure access. To the front of this picture is an entrance to the facility. Relocated 90 TR packaged liquid chiller (R-22) along a heavily used walkway (circa 2007). Unit additional located along the side of the building. For aesthetics the University encumbered additional resources to mask enclosure with the extensive brick work to match the facilities. Louvers are painted black. Windows of facility are operable. No refrigerant relief piping following ASHRAE standard was considered. The needs of the project in the specific location and the functional operation of the equipment were the design focus. Package air cooled chillers (R-22) & Dx condensing unit (R-22) installed 2003 outside of existing 1950 Arena. Facility has operable windows for occupants and athletic venues for students where pedestrian traffic is within 20-25 feet of equipment. No relief piping considered. 100 TR packaged chiller (R-410a) installed 2006 with out consideration of relief piping. Note, this is the first larger installation on campus using R410a. Secure fencing around the equipment located in the back parking lot and general entrance to the facility is provided and keyed to University secure mechanical access. Dx (R-22) condensers for computer facility. Note no true separation from pedestrian paths and entrance to this facility exist. Brick facade shield is for aesthetic masking of units from another facility, not security in assess. Two units foreground were installed by a third party for a computer partnership. All piping viewed is for refrigerant condensing (Hot Gas & Conds. Liq). Windows of facility are all operable. Area in background installed 2006. Same condenser field with improved view of pedestrian access. Red van sits in front of one of four dormitories in this area. My design allowance: Pictures show non conformance of relief piping for a 350 TR R123 centrifugal. Installed circa 1996-97, the relief could not be economically piped through the facility, nor could it run up the side of the facility due to the location of the MER and chiller. Selection was made and determined based upon extending the relief away from the facility approx. 12’ and away from the side walk by approx 20’. Goose neck of piping considered should a relief discharge occur the wall (exhaust air plenum) would blow refrigerant away from facility (closed area). In summer the tree in foreground helps to hide the relief piping. Note design challenge: Original chiller refrigerant relief was not piped to atmosphere, rather relieved to the MER typical of the 1960’s installations. Circa 2003-04 dedicated OA chiller at approximately 70 TR. Unit installed outside of facility with other Dx condensing systems running through one of two wings (old wing circa 1950). DOAS serves new (circa 1968) wing in background. No relief piping considered for project. No secure site access considered with location though to the left of the 70 TR chiller is an aesthetic wall to mask the unit from a major pedestrian walk way between campus. ATTACHMENT ‘J’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ASHRAE Std. 15-2004 CM-15-05-12-0004/001 (K. McClure) Re: 8.11.5 Proposed change REFRIGERANT VAPOR REMOVAL When the exhaust is used to remove refrigerant vapors, the suction opening of the exhaust fan ductwork to shall be no less than 24” from the floor or the lowest part of the Room where refrigerant gas is likely to accumulate. All refrigerants except ammonia Are heavier than air. Comments •Grammar is incorrect. Clarification is needed from the submitter. It is believed that what was intended was to require suction opening to be no more than 24” from the floor. •Regarding ammonia - There are other refrigerants that are lighter than air. •Standard 15-2004 does not specify a height limit or provide for a specific location for exhaust air duct inlet openings. •Standard 15 requires that the inlet and outlet exhaust locations do not lead to recirculation. •The User’s Manual provides guidance by indicating that such duct inlets should be located in the breathing space (a height of 5’ or less). •The User’s Manual suggests that the inlet and outlet exhaust locations should set up an effective sweeping action that does not leave any dead zones. Recommendation Incorporate the User’s Manual points above, incorporate a phrase indicating that inlet and outlet duct location should take into account the density of the refrigerant relative to air [akin to 8.11.5 (d)]. • 8.11.5 (d) Location of the gravity ventilation openings shall be based on the relative density of the refrigerant to air. Recommended changes – 8.11.5 Placement after (b) When the exhaust is used to remove refrigerant vapors, location of the ventilation openings shall take into account the density of the refrigerant relative to air. The suction opening of the exhaust fan ductwork shall be located as follows: i) Suction exhaust openings for heavier-than-air refrigerants shall be located in the lower portion of the breathing space not greater than 36 inches from the floor. Additional exhaust opening(s) shall be located to exhaust pump pits or other low points in the machinery room where applicable. ii) Suction exhaust openings for lighter-than-air refrigerants shall be taken from the ceiling or wall locations not lower than the highest 15% of the room’s volume. •Regular ceiling offsets of 0.3% relative to the room volume that have a depth/width (where width is the minimum horizontal dimension) ratio of 5 or greater shall be subject to (ii). •Design of exhaust for machinery rooms with irregular ceiling profiles shall be via approved engineering analysis. •Note: Suction opening and return air opening locations should set up a sweeping action across the room; for example, by locating openings on opposite sides of the room or in diagonally opposite corners. (Re-number clauses/sub-clauses.) ATTACHMENT ‘K’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ATTACHMENT ‘L’ These Minutes were approved by vote of this Committee and are the official, approved record of the proceedings. ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. Meeting Minutes ASHRAE SSPC 15 ISO 5149 Ad Hoc Sunday, June 24, 2007 Long Beach, CA The meeting of ASHRAE SSPC-15 ISO 5149 Ad Hoc Committee was held at 11:00 AM on June 24, 2007. As an ad hoc committee, there is no formal membership for this committee. Jay Kohler serves as chair of the committee. An agenda was distributed by the chair. 1. AGENDA ITEM 1 – Status of Recent and Upcoming Events. This is an FYI item and no actions are required. The key upcoming event is the August 9 deadline for conclusion of the 2nd CD comment period. Also, the date for the next SC1 meeting in Ostende is Oct 16 – 17. 2. AGENDA ITEM 2 – Review of response to US comments We need to resubmit comments from the 1st CD that were not properly addressed in the 2nd CD. We briefly discussed those 1st CD comments. Jay Kohler will review the prior list for resubmittal comments and distribute this list to the ad hoc committee. There is a New Work Item (NWI) referenced in some of the comments. It is unclear as to what became of this item. Doug Tucker will contact Jeanne Mandeng to find out the status of the item. Gary Zyhowski reviewed and commented on Table A.1 in Part 1 (See Dallas minutes item 3a). A copy of his comments will be distributed with these minutes. All need to review these comments to determine if they should be submitted. Gary – can these comments be consolidated into a single comment, and include a revised version of the table? I believe these comments really should be considered as a group and not individually. Gene Troy will submit a comment regarding the classification of plate heat exchangers (See Dallas minutes item 3d) 3. AGENDA ITEM 3 – Discussion of flammability issues. A new document (N316) was distributed recently. This item is believed to address item 3b from the Dallas minutes and is intended to address our concerns about the use of flammable refrigerants in mini-splits. Jim Crawford and Bob Richards will review and comment. Others are encouraged to do the same. We understand that this proposal is not contained in the 2nd CD. 4. AGENDA ITEM 4 – Schedule for subsequent ad hoc meeting A conference call is schedule for July 12 @ 2:00 PM EDT. Doug Tucker will arrange for this call. 5. Submission of comments Comments from the Std 15 ad hoc committee will be forwarded to the US Tag to ISO/TC 86/SC 1 for submission to ISO. The US side needs to determine whether or not to vote in favor of advancing to the DIS stage. 6. In-Country clause If acceptable changes cannot be included in the document, an approach to consider is the use of In-Country clauses to incorporate specific restrictions for US application. Ad hoc members are encouraged to consider implications. 7. Meeting adjourned. Recorded by Jay Kohler
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