This document discusses refrigerants that can replace R410A in comfort applications to meet the F-gas phase down regulations. It finds that R32 demonstrates slightly better performance than R410A, increasing capacity by 6% and seasonal efficiency by 1-2%. HFO blends and propane offer alternatives for residential heat pumps. A2L refrigerants require safety modifications but can be used in existing R410A designs. The new IEC standard eases integration of electronics in A2L systems. Overall solutions exist to comply with regulations while maintaining performance.

1. Low GWP Refrigerants for Comfort
Applications
Refrigeranti a basso GWP per il
Condizionamento e Pompe di Calore
Bachir Bella
IL PASSAGGIO AI REFRIGERANTI ALTERNATIVI:
IMPATTO SU NUOVI E VECCHI IMPIANTI
MCE 2018

2. Agenda
 Refrigerant dilemma for comfort to meet F-gas phase down
 R32 performance for commercial comfort
 HFO blends and R290 performances for residential heat pump
 Flammability impact
 Conclusion
2

3. Refrigerants Landscape & LGWP Candidates to Meet F-gas Phase Down
Average GWP to meet Phase Down target
R410A
Like
R407C
Like
R134a
Like
GWP
< 1500
~600
~150
R1234yf
R1234ze
R410A
0 500 1000 1500 2000
VolumetricCapacity/Pressure
R448A/
R449A
R32/
R452B, R454B
R134a
R455A/
R454C
R450A/
R513A
460-698
150
1
2
2030
R407C
A1 - Non flammable
A2L - Mildly Flammable
A3 - Flammable
R290
2
2024 20182021 2015
- 37%-29%-31%-32%
~600
Years
Average GWP~900~400 ~1300 ~2000
Refrigerants below 150 GWP are well accepted as future proof long term solution
R410A is the
highest GWP

4. R410A
Replacement?
4
R32
HFO
Blends
GWP 460-700
0%
36%
2%
11%15%
27%
9%
Domestic Refrigeration
Commercial Refrigeration
Transport Refrigeration
Industrial Refrigeration
Mobile air-conditioning
Stationary air-conditioning and
heat pumps
Chillers & hydronic heat pumps
R32, HC,
HFO blends
High Glide
Efficiency?
High
Pressure
Total Annual Refrigerant consumption in CO2 Equivalent
Medium
Pressure
0
2
4
6
8
10
12
14
16
-60 -40 -20 0 20 40 60 80 100
EffectivelTemperauteGlide(K)
Evaporator Side
Condenser Side
GWP
Sustainability?
HFO
blends
GWP ~148
2015 consumption
R290
GWP 3
Charge Limit
Flammability?
System
Redesign
Near Drop-In

5. AHRI Evaluation Program (AREP)
Phase I & II Tests Results – Summary for R410A Near Drop-in Candidates
 R32 test results improved in AREPII
 R1234yf-based blends as leading near drop-in
A2L candidates in Capacity
 R1234ze-based blends tend to require more
compressor upsizing and higher temperature
glide
5
-8%
-6%
-4%
-2%
0%
2%
4%
6%
-15% -10% -5% 0% 5% 10% 15%
R32 - AREP 1.0
R32 - AREP 2.0
R452B(DR-55) - AREP 2.0
R454B (DR-5A) - AREP 2.0
L41-2 - AREP 2.0
R32
R452B/
R454B
R446A/
R447A
s
source : AHRIAREP Conferences & reports
% R410 EER (82F)
% R410 Cap (95F)
Composition GWP
(AR4)
R454B R32 68.9%/R1234yf 31.1% 460
R452B R32 67%/R1234yf 26%/R125 7% 698
R446A R32 68%/R1234ze 29%/R600 3% 461
R447A R32 68%/R1234ze 28.5%/R125 3.5% 583

6. Near Drop-In Candidates Evaluation
Key Differences
6
A2L
BV = 6.7
A2L
BV = 3
+ 1 - 6%
GWP / Charge %
to R410A
Compressor
Design & Cost
Efficiency Vs.
R410A
Flammability/
Burn Velocity
Refrigerant Cost
R452B /R32
DT*/Oil
& Envelope
675 / -20%
R32 DT Concerns
Varying BV but All
are A2L
460 / -10%
A2L
BV = 5
Cooling Capacity
(vs. R410A)
R454B
698 / -10%
Near
Drop-In
If Equal Capacity
~30% R1234yf
5% Compr.
Downsize
R454B Best GWP
Vs. R410A
R1234yf Cost
0 - 4%
*Compressor Discharge Temperature
MEPS
(Ecodesign)
GWP
(F-gas)
Flammability
(Codes)
TEWI
Cost
Evaluating R410A
alternatives by
balancing TEWI
and A2L
Flammability as
they jointly
impact overall
system cost.

7. Scroll Performance w/ R410A & R32
Compressor Result System Effect
Higher capacity (Avg. +7 %) Smaller displacement
Higher efficiency (~ 2 %) Expected similar to higher SEER
Higher discharge Temp.
at high pressure ratio
Heat pump limit at low ambient temperature
Option.: design optimization /mitigation
-20 -15 -10 -5 0 5 10 15 20 -20 -15 -10 -5 0 5 10 15 20
25 5 % 5 % 5 % 5 % 5 % 4 % 2 % 1 % 0 % 0 % 0 % 0 %
30 5 % 5 % 6 % 5 % 5 % 5 % 5 % 1 % 1 % 0 % 0 % -1 % -1 % -1 %
35 6 % 6 % 6 % 6 % 6 % 5 % 5 % 1 % 1 % 0 % 0 % 0 % -1 % -2 %
40 6 % 7 % 7 % 6 % 6 % 6 % 1 % 1 % 1 % 1 % 0 % -1 %
45 7 % 7 % 8 % 7 % 7 % 7 % 2 % 2 % 2 % 1 % 0 % -1 %
50 8 % 9 % 9 % 9 % 9 % 8 % 2 % 3 % 3 % 3 % 2 % 0 %
55 10 % 10 % 10 % 10 % 10 % 4 % 4 % 4 % 4 % 2 %
60 13 % 13 % 13 % 12 % 5 % 6 % 6 % 4 %
62 14 % 14 % 14 % 7 % 6 % 5 %
Evaporating Temperature (°C) Evaporating Temperature (°C)
CodensingTemperature(°C)
Cooling Capacity Variation COP
-25 -20 -15 -10 -5 0 5 10 15
25
30
35
40
45
50
55
60
65
160
150
140
130
120
110
100
90
80
70
60
-25 -20 -15 -10 -5 0 5 10 15
25
30
35
40
45
50
55
60
65
T0
Tc
Discharge Temperature [°C] & Pressure ratio
2
3
45
6
7
8
-25 -20 -15 -10 -5 0 5 10 15
25
30
35
40
45
50
55
60
65
160
150
140
130
120
110
100
90
80
70
60
-25 -20 -15 -10 -5 0 5 10 15
25
30
35
40
45
50
55
60
65
T0
Tc
2
3
45
6
7
8
Discharge Temperature [°C] & Pressure ratio

8. Poor Miscibility Std. POE / R-32
-60
-40
-20
0
20
40
60
80
100
0 10 20 30 40 50 60
PhaseSeparationTemperature(°C)
Lubricant in Refrigeant by Weight %
Lubribricant- RefrigerantMiscibilty Curves
POE/R-410A
POE/R-32
Oil B / R-32
R-32 Critical temperature
POE Lubricity & Miscibility with R32
Lubrication Reliability POE/R32
Lubricant Result
Fixed Scroll Orbit Scroll
POE “A” Severe Wear
POE “B” Improved
POE “C” Good
Scroll
Over Heated
Scroll
Over Heated
Scroll
Over Heated
Scroll
Over Heated
Non Over Heated
Non Over Heated
New POE Lubricant is Required for R32

9. 9
• Refrigerant: R410A
• Nominal R410A cooling capacity 74 kW
• Two finned coil condensers in parallel
• One BPHE evaporator
• Two scroll compressors in parallel
0%
0%
1%
3%
6% 6% 6%
5%
-2%
0%
2%
4%
6%
8%
10%
100% 74% 47% 21%
0
2
4
6
8
10
12
14
16
18
20
R32Performancevs.R410A
Cooling Load
DischargeTemp.R32-R410A(°C)
SEERon Cooling Load - 74 kW
COP Cooling capacity Disch. Temperature
Average SEER + 3%
0%
2%
2%
1%
2%
6%
7% 7%
6%
6%
-2%
3%
8%
13%
18%
100% 88% 54% 35% 15%
0
5
10
15
20
25
30
35
40
45
R32Performancevs.R410A
Heating Load
DischargeTemp.R32-R410A(°C)
SCOPon Heating Load - 70 kW at -10°C
COP Heating Capacity Discharge temp.
Average SCOP + 2%
Source:
• Bella et al. (2014) Purdue Conference
• Zilio et al. (2015) Science and Technology for the Built Environment
Performance & Seasonal Efficiency of a Reversible
Chiller with R32 & R410A - Case Study
R32 gives slightly higher seasonal efficiency
due to higher heat transfer properties
Hot Climate
Average Climate

10. Scroll Performance for Residential HP at Standard Rating
with High & Medium Pressure Refrigerants
10
R410A-like
R452B/R32/R454B vs R410A
R407C-like
R290/R454C/R455A vs R407C
-6.7/50/10K SH/0K SC
96%
99%
108%
104%
94%
102%
85%
90%
95%
100%
105%
110%
Capacity COP
R452B R32 R454B
11
32
11
0
40
R452B R32 R454B
91%
101%
93%
107%
99%
102%
85%
90%
95%
100%
105%
110%
Capacity COP
R290 R454C R455A
-13
-9
-6
-20
0
R290 R454C R455A
PerformanceDisch.Temp.(K)
Evap: -6.7°C, Cond:50 °C, 10K SH & 0K SC

11. R290 Map & Efficiency Vs R410A
No EVI (No Vapor Injection) EVI (w/ Vapor Injection)
• R290 is showing very promising performances versus R410A compressors both EVI and non-EVI
• Thanks to its properties R290 has good performance at higher pressure ratio
• The low discharge temperature is compensating the EVI need w/ R410A at low evaporating and high condensing
temperatures with a positive impact on the system cost
-5%
-1%
0%
-1%
2%
0
10
20
30
40
50
60
70
80
-35 -25 -15 -5 5 15 25
-8%
2%
0%
-4%
-5%
0
10
20
30
40
50
60
70
80
-35 -25 -15 -5 5 15 25
R290
w/o vapor injection
R410
w/Vapor Injection
R290
w/o vapor injection
R410
w/o Vapor Injection
HCOP Comparison HCOP Comparison

12. Impact Of Flammability on Scroll
12
PED Risk Mitigation
Increase use of compressor integrated
electronics (Inverter, Controller..) require a risk
assessment and mitigation
• Flammability Definition is not aligned with
ASHRAE 34 – No difference between A2L/ A3
• R410A Scroll compressor w/ (A2L/A2/A3)
belongs to higher PED category (2014/68/EU)
• Higher PED category define more stringent
requirement
Source: Eiji Hihara – University of Tokyo – Research project on risk assessment of Mildly
Flammable refrigerants
PED Category I II III
Pressure x Volume
(bar.liter)
Non
flammable
50 - 200 200 -1000 1000 -
3000
Flammable 25 - 50 50 - 200 200 - 1000
Quality System approval Internal NB NB
Design Review Internal Internal NB
Welding process approval Internal NB NB
Weld Inspection (Non destructive Test) - - NB
R410A Scroll cannot be used with an A2L R410A-like refrigerant due to higher PED category

13. A2L Low Burning velocity Requires Lower Protection for Electrical Components
According to New IEC60335-2-40 Standard
Electrical Switching Load
Clause 22
• Max opening size in relays and similar
components
• Switching devices are not source if
switched electrical load is less than:
– 𝐿 𝑒 = 5 × (
6.7
𝑆 𝑢
)4
when breaking all phases
– 𝐿 𝑒 = 2.5 × (
6.7
𝑆 𝑢
)4
When breaking 2 legs of a 3ph load, or
when breaking one or 2 legs of a 1ph load
R32 R452B R454C R455A R290(*)
Burning Velocity
[cm/s]
6.7 3 1.5 1.6 39
Le (3 legs)
[kVA]
5 124 1990 1537 0.004
Le (2 or 1 leg)
[kVA]
2.5 62 995 769 0.002
R32 R452B R454C R455A R290(*)
Deff Calculated 2.8 6.7 14.3 13.4 0.4
Dmax (Quench) 2.8 6.7 7.0 7.0
*R290 data are for reference ONLY. Formula do not apply to A3
Quenching Effect (Extinction diameter)
Annex JJ
Flame go out thru the opening
Source: IEC60335-2-40:2018

14. Summary and Conclusions
• AREP find out that R32, R454B and R452B are near drop-in candidates for R410A
• Trade-offs between flammability, GWP and efficiency is the best approach for
selecting the combination refrigerant/application
• R32 demonstrates to outperform R410A capacity by some 6 % and seasonal
efficiency by 1 to 2 %
• HFO blends and R290 offer good performance refrigerants for HP residential
system to replace today HFC. R290 offers a wide operating application
• A2L refrigerants are not a drop-in solutions due to PED, flammability but are
attractive for OEM who’d like to keep their R407C/R410A design
• IEC60335-2-40:2018 standard results in an easier integration of electrical and
electronics components in A2L system
• Solutions exist to comply with ErP directive and F-gas phase down scenario
14