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