The document discusses the use of variable speed compressors and fans in commercial refrigeration applications to improve off-design efficiency. It notes that variable speed technologies allow systems to better adapt to actual operating conditions, where off-design performance accounts for most usage. Test results showed that variable speed cabinets and remote systems had improved temperature control and reduced energy consumption compared to fixed speed alternatives. The conclusion is that variable speed components break traditional design rules and allow for optimized sizing and energy usage across all operating conditions.

1. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
COMMERCIAL REFRIGERATION APPLICATION
OF VARIABLE SPEED COMPRESSOR
AND VARIABLE SPEED FANS FOR IMPROVED
OFF-DESIGN EFFICIENCY
Maurizio Orlandi - Federico Mattia Visconti – Anna Ruggeri
• Innovation Centre Epta

2. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Commercial Refrigeration
Remote
Plug-in
PacksColdrooms
Remote

3. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Commercial Refrigeration
Remote
Plug-in
PacksColdroo
ms
Remote

4. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
European Regulation scenario
ECODESIGN
FGAS
CO2, lowGWP
EFFICIENCYEFFICIENCYEFFICIENCY
HVAC^R
€€ - $$ - ¥¥ - ££

5. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable speed
• Variable speed is a
known way get
efficiency
• Exemples:
Compressors Lot 31
Water circulator Lot11 Reg.
641/2009
Heat Pump Lot 21
ηηηη
Seasonal off-design
SYSTEM efficiency
(SEER,SCOP)

6. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Display cabinet Field conditions
• adapt to condition of use where off-design condition
accounts for most of the time
Example of
ISO 23953
class 3
25°C/60%HR
Variable Speed Water
Condensed Cabinet
Variable Air Flow Cabinet

7. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Water Loop

8. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Water Loop
• Identical
cabinet have
differences on
average of
1÷3 °C Tev
T Evaporazione (15/05/2015)
-20
-15
-10
-5
0
5
10
15
06:00
06:30
07:00
07:30
08:00
08:30
09:00
09:30
10:00
10:30
11:00
11:30
12:00
12:30
13:00
13:30
14:00
14:30
15:00
15:30
16:00
16:30
17:00
17:30
18:00
18:30
19:00
19:30
20:00
20:30
21:00
21:30
22:00
22:30
23:00
23:30
00:00
Focusing our view on
off-design

9. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Water Loop
• Evaporation temperature : Compariso of a
variable speed and standard remote

10. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Water Loop
CO2 emission*
* North Italy
Operating Cost

11. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable Speed fans

12. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Radiation
Variable Speed fans
Image credits : http://www.energieplus-lesite.be/

13. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable speed fans
• A detailed CFD freezer simulation

14. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable speed fans
Comparing air flow identical load but
Reduced to a significant off-design condition

15. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable Speed fans
• Results of the simulated
portion LT full glass door

16. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Variable speed fans
• CONCLUSION
– Variable speed fan can break the design rule OF
FIXED SPEED
– Trade off between size of component
– More “design” fan power can be added to the
project if variable speed
• example size of an evaporator -designed for the peak-,
but at the same time run slowly and with reduced
power when system is working off the peak.