R32 Your Low GWP Air Conditioning

Solution

ACR Journal – Webinar - 17th March 2016

Why another refrigerant? The F-Gas Revision New Equipment Ban:

0

What is R32? A low GWP HFC refrigerant

• GWP of 675 • Significantly lower than R410A

Preferred replacement for

R410A

Uses similar technology Improved Cooling Capacity

Better Energy Efficiency

Physical Properties • Non-toxic

• Excellent thermal properties

– Pressures are slightly higher than R410A

– R410A 296psi/20.4bar @ 35oC

– R32 303psi/20.9bar @ 35oC

• High volumetric capacity

• Low boiling point of -52oC

• Odourless

• Mildly flammable

Several legislative issues to be aware of:

ADR (transport of dangerous goods) • R32 is classified as Class 2.1 Flammable for transport

• Treat the same way as propane etc.

Flammability ?

Design and Construction of refrigeration systems • A2L is a new ASHRAE category for “mildly flammable

refrigerants”

• EN378 currently under revision to take account of this new category

Dangerous substances & Explosive Atmospheres Regulations (DSEAR) • Ignition sources, avoidance of flammable atmospheres

etc

How easy is R32 to ignite?

How easy is R32 to ignite?

• Lower flammability limit 14% in air (~300g/m3)1

• Upper flammability limit 31% in air (~660g/m3)1

• A naked flame is required for R32 to ignite

• Low burning velocity makes ignition & flame propagation difficult (but not impossible)

• Risks are lower than propane and other hydrocarbons

– However don’t ignore obligations under DSEAR

– No venting, no sources of ignition, appropriate equipment

EN378 - application EN378-1 2008 restricts the application of flammable refrigerants

M = 2.5 x LFL1.25 x h x √A ** M = max charge, kg LFL = lower flammability limit, kg/m3 h = height of unit, m, (0.6 for floor mounted, 1.0 for window, 1.8 for wall, 2.2 for ceiling) A = floor area, m2

R32 R290 (propane)

Max refrigerant charge

8.84kg 0.65kg

Example: Comfort cooling, cassette in a 9m x 5.5m room *2

** For comfort cooling applications only. Other limits exist for depending on application. Please see EN378

The Cylinders: • Valve outlet is DIN-477 left

hand thread

– Adaptors will be required to suit refrigeration hoses

• A range of sizes available:

– 5kg, 10kg, 20kg & 45kg

• Red topped to aid easy recognition that it is flammable

“Best practice” procedures are required:

Good Quality Brazed Joints

Purge Whilst Brazing

Leak Prevention and Detection Flammable Recovery/Receiver Cylinders

Special Tools

Summary:

R32 should prove no more difficult to handle than R410A Be aware of the properties – risks are easily managed-Follow good refrigeration practice Experience with R32 is a good grounding for many new Low GWP refrigerants which are likely to be mildly flammable Keep up to date with industry developments

Remember: …Look for the logo to ensure what you are using is:

References 1. Flammability limits from Air Liquide Gas Encyclopedia. Quoted at STP. 2. IOR Technical bulletin 39

THANK YOU FOR LISTENING