ISO 5149 – Impact on RAC Installation and Servicing

ISO 5149 – Impact on RAC Installation
and Servicing
Thanavat Junchaya
Implementing Agency Coordination Unit
Annual Joint Network Meeting of National Ozone Officers of Latin America and the Caribbean, The Dominican Republic 2-5 December 2014
International Standard ISO 5149
 Refrigerating systems and heat pumps – Safety and
environmental requirements
 First Edition 2014-04-15 replaces ISO 5149:1993
 The revision was promoted by entry of new refrigerants
and blends in the market and the introduction of new
safety classifications
 Consists of the following parts:
 Part 1: Definitions, classification and selection criteria;
 Part 2: Design, construction, testing, marking and
documentation;
 Part 3: Installation site; and
 Part 4: Operation, maintenance, repair and recovery
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Refrigerant Safety Classification
Safety Group
Higher
flammability
Lower
flammability
No flame
propagation
A3
B3
A2
B2
A2L*
B2L*
A1
B1
Lower Toxicity
PEL > 400 PPM
Higher Toxicity
PEL < 400 PPM
* Maximum burning velocity ≤ 10 cm/s
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LFL ≤ 0.1 kg/m3 or
HC ≥ 19 MJ/kg
LFL > 0.1 kg/m3 and
HC < 19 MJ/kg
Low-GWP Alternatives &
Refrigerant Safety Classification
GWP
A1
<10
R-744
11 – 500
4
A2
HFC-152a
501 – 1,000
R-450A,
XP-10
1,0001– 1,500
HFC-134a,
R-448A,
R-449A
1,501 – 2,000
R-407C,
R-407F
2,001 – 3,000
HCFC-22,
R-407A,
R-410A
> 3,001
CFC-12,
R-404A
A2L
A3
B2L
HFC-1234yf,
HFC-1234ze
HC-290,
HC-600a,
HC-1270
R-717
L-40, L-41,
DR-5,
R-444B,
446A, 447A
HFC-32
HFC-143a
Part 1 of ISO 5149:2014
Definition, classification and selection criteria
 This part applies to:
 Refrigerating systems, stationary or mobile (except vehicle
air conditioning systems) of all sizes including heat pumps;
 Secondary cooling or heating systems;
 The location of the refrigerating systems;
 New systems, extensions or modifications of any existing
systems, and for used systems, being transferred to and
operated on another site, as well as in the case of the
conversion of a system to another refrigerant.
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Refrigerant Charge Limit
 ISO 5149 determines refrigerant charge limit
of refrigerating systems depending on:
 Occupancy classification;
 Location classification of refrigerating systems;
 Specific toxicity and flammability characteristics
of the refrigerant used
 The charge limit can be an absolute value or
calculated from characteristic refrigerant data
and room volumes
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Occupancy Classification
 General occupancy “a” (hotels, schools, restaurant)
Rooms, parts of building where any person has access without being
personally acquainted with the necessary safety precautions;
 Supervised occupancy “b” (offices)
Rooms, parts of buildings, buildings where only a limited number of
people can be assembled, some being necessarily acquainted with
the general safety precautions of the establishment;
 Authorized occupancy “c” (manufacturing facilities)
Rooms, parts of buildings, buildings where only authorized persons
have access, who are acquainted with general and special safety
precautions of the establishment and where manufacturing,
processing, or storage of material or products take place.
Note: Machinery rooms shall not be considered as an occupied space except
as defined in ISO 5149-3: 2014, 5.1.
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Location Classification of
Refrigerating Systems
 Class I: mechanical equipment located within the
occupied space – the refrigerating system or refrigerantcontaining parts are located in the occupied space;
 Class II: compressors in machinery room or open air –
all compressors and pressure vessels are either located
in a machinery room or in the open air; coil-type heat
exchangers and pipework, including valves, can be
located in an occupied space;
 Class III: machinery room or open air – all refrigerantcontaining parts are located in the machinery room or
open air. The machinery room should fulfil the
requirements of ISO 5149-3; and
 Class IV: ventilated enclosures – all refrigerantcontaining parts are located in the ventilated enclosures.
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Charge Limit Requirements for
A2L Refrigerant
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Charge Limit Requirements for
A3 Refrigerant
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Method to Determine Charge
Limit of a Refrigerating System
1. Define which occupancy category (a, b, or c) applies and
which location class (I, II, III, or IV) the system is used in
2. Define the toxicity class of the refrigerant (A or B)
3. The toxicity limit equals ATEL/ODL values or practical limits
whichever is higher
4. Determine the charge limit (toxicity)
5. Define the flammability class of the refrigerant (1, 2L, 2, 3,
etc.) used in the refrigerating system and the corresponding
LFL
6. Determine the charge limit (flammability)
7. The lowest refrigerant charge obtained according to 3) and
5) is applied
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Case Study
 Occupancy
 Our interest is in residential air-conditioning system which
can be installed in home or offices; hence, general
occupancy/human comfort is considered as it establishes a
conservative baseline.
 Location of refrigerating systems
 Classes I and II which are applicable for unitary and split
systems are considered in details; and
 Classes III and IV which are applicable for larger airconditioning systems will be touched on briefly.
 Refrigerant
 R-32 is considered as an example for A2L materials; and
 R-290 is considered as an example for A3 materials.
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CAP Factor
 The charge limits in are capped to a limit based upon the
LFL of the refrigerant.
 In the case of flammability class 2 or 3 refrigerants, the
basic cap factor is m1, m2, and m3.
 For flammability class 2L refrigerants, the basic cap factor is
increased by a factor of 1.5 due to lower burning velocity
 There are no room volume restrictions for refrigerant
charges below or equal to m1
Cap Factor
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R-32 (kg)
R-290 (kg)
m1 = 4 m3 x LFL
1.8*
0.15
m2 = 26 m3 x LFL
12*
1.0
m3 = 130 m3 x LFL
60*
5.0
* Increased by a factor of 1.5
For AC with Refrigerant-Containing Parts
used for Human Comfort and Charge > m1
Charge limits are determined by:
𝑚𝑚𝑎𝑥 = 2.5 × 𝐿𝐹𝐿5/4 × ℎ𝑜 × 𝐴1/2
where:
mmax
allowable maximum charge in a room (kg)
m
refrigerant charge amount in the system (kg)
A
room area (m2);
LFL
Lower Flammability Limit (kg/m3);
h0
height factor based upon the method of mounting the
appliance (m)
14 Note:
floor: 0.6m, window: 1.0m, wall: 1.8m, ceiling:2.2m
Maximum Charge Limit for HFC-32 AC used
in Class I or II location for human comfort
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Comparison of Maximum Charge Limit
between R-32 and R-290 Wall-Mounted AC
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Cooling Load and Impact from
ISO 5149 Charge Limit
Cooling Load Estimate
Basic Assumptions

Room size = 30 m2
Mounted
locations

Cooling load = 600 BTU/hr/m2
(175 W/m2)

Cooling requirement = 18,000
BTU/hr (~3.5 kW)

Estimate refrigerant charge for
18,000 BTU/hr AC:
 R-290 (@ 0.3 kg/RT) = 0.45 kg
 R-32 (@ 0.7 kg/RT) = 1.05 kg
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ISO 5149 Charge Limit
R-290
R-32
Floor
0.15
1.88
Window
0.23
3.13
Wall
0.41
5.73
Ceiling
0.51
6.88
Charge Limits for R-32 (12 kg
<m<60 kg)
 Charge limits are determined by:
 m = Room Volume x QLMV where QLMV for R-32 is 0.063;
 If cooling load demands m resulting in concentration higher
than 0.063, measure(s) described in ISO 5149-3: 2014 are
required.
 Room Volume = Floor area x Height (2.2 meter).
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Conclusions (I)
 For residential a/c systems
 R-32:
 for charge size (m) less than 1.8 kg, there are no restrictions;
 for 1.8 kg <m< 12 kg, m should be less than mmax;
 For 12 kg <m< 60 kg, refrigerant concentration in case of full
leakage should be less than 0.063 kg/m3. If so, no additional
measures are required. If not, measures defined in ISO 51493:2014 should be applied.
 R-290
 for charge size (m) less than 0.15 kg, there are no restrictions;
 for 0.15 kg <m< 1 kg, m should be less than mmax;
 for residential a/c, m cannot exceed 1 kg.
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Conclusions (II)
 For Classes III and IV (chillers)
 R-32:
 No charge size restrictions for Class III for which all refrigerantcontaining parts are installed in a machinery room with mechanical
ventilation or in open air;
 Charge size should not exceed 60 kg if all refrigerant-containing
parts are installed in ventilated area (Class IV) where no mechanical
ventilation.
 R-290
 Charge size should not exceed 1 kg in case the machinery room is
below ground, 5 kg in case the machinery room is above ground;
 Charge size should not exceed 5 kg in case all refrigerant-containing
parts are installed in ventilated area.
 For supervised occupancy area, the charge size could increase to 10
kg; and for authorized occupancy area with a machinery room or
open air located above ground, there is no charge size restriction,
however, measures prescribed in ISO5149-3 must be applied.
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Impact on RAC Manufacturing,
Installation, and Servicing
 Safety measures must be put in place properly at the
manufacturing facilities;
 Proper care is needed for transport of refrigerant and
final products;
 Installation must be done by qualified technicians and
must be in compliance with local regulations and
standards;
 Servicing must be performed by well trained technicians
– most challenging task as it involves behavior changes;
 Public must be aware of the need to have well trained
technicians operating on their RACs. However, public
education must be done strategically; otherwise, it may
lead to adverse repercussion;
 Flammable nature of new refrigerant also provides
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opportunities for upgrading the service industry.
Thank you
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