Thanavat Junchaya WB ISO 5149 Dominican Republic Presentation Thanavat

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 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 6

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. 8

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