Compressed Air Systems

Different cost elements connected to compressed air systems. Compressed air systems are found in most industries and are typically used for production processes, for material handling and for refrigeration. Of all motor systems, compressed air systems are typically the least energy efficient, with 80% of the input energy lost to the heat of compression (assuming no recovery of the resulting low grade heat, which is uncommon) and overall system efficiencies remaining at around 10–15%. This makes compressed air one of the most expensive forms of energy in an industrial plant. As can also be seen in the figure, the energy costs represent more than 70% of a compressor's total costs. Making matters worse, compressed air systems require close process control, which until recently prioritized reliability often at the expense of higher energy consumption.

In most compressed air systems around 30% of the compressed air is lost due to leaks, poor maintenance, mis-application and inadequate control. Consequently, efficiency improvements in compressed air systems are particularly important. A wide range of proven improvement opportunities exist for compressed air systems and can provide up to 20% efficiency gains – depending on specific conditions on the plant – even individually (UNIDO, 2010).

Compressed Air SystemsSchematic

Compressed Air SystemsTechnologies & Measures

Technology or MeasureEnergy Savings PotentialCO2 Emission Reduction Potential Based on LiteratureCostsDevelopment Status
Systemic Leak Reduction & System Control Optimization

When combined with optimized compressor system controls, systemic leak management can offer the following improvement potentials:
• 20% for low efficiency base cases;
• 15% for medium efficiency base cases;
• 10% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 7073 77658
Canada 1867 23258
EU 6190 58158
Thailand 986 9925
Vietnam 444 6336
brazil 1814 20247

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 4263
Canada 928
EU 2699
Thailand 512
Vietnam 218
brazil 265

Estimated typical capital costs for systemic leak management, combined with system controls, for different system sizes (S) are:
• US $1250  for S < 37 kW;
• US $3000 for 37 kW < S < 75 kW;
• US $5000 for 75 kW < S < 150 kW;
• US $5000 for 150 kW < S < 375 kW;
• US $5000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 14.4
Canada 15.1
EU 17
Thailand 5.4
Vietnam 5.4
brazil 6.1

Commercial
Low Pressure Drop In Treatment Equipment

This measure is estimated to offer following improvement potentials:
• 5% for low efficiency base cases;
• 3% for medium efficiency base cases;
• 1% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

 
  Final (GWh/y) Primary (TJ/y)
US  534 5866
Canada 141 1757
EU 468 4394
Thailand 84 840
Vietnam 38 537
brazil 117 1308

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 322
Canada 70
EU 204
Thailand 43
Vietnam 19
brazil 17

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $1500  for S < 37 kW;
• US $3000 for 37 kW < S < 75 kW;
• US $5000 for 75 kW < S < 150 kW;
• US $12000 for 150 kW < S < 375 kW;
• US $18000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 129.7
Canada 130.9
EU 139.9
Thailand 55.2
Vietnam 54.8
brazil 72

Predictive Maintenance Program

This measure is estimated to offer following improvement potentials:
• 10% for low efficiency base cases;
• 5% for medium efficiency base cases;
• 1% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 1964 21572
Canada 519 6461
EU 1507 14160
Thailand 641 9925
Vietnam 288 4119
brazil 698 7787

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 1184
Canada 258
EU 657
Thailand 333
Vietnam 141
brazil 101

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $500  for S < 37 kW;
• US $1000 for 37 kW < S < 75 kW;
• US $2000 for 75 kW < S < 150 kW;
• US $5000 for 150 kW < S < 375 kW;
• US $10000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 33.4
Canada 33.7
EU 36.9
Thailand 4
Vietnam 4
brazil 7.4

Commercial
Matching Air Quality to Demand Needs

This measure is estimated to offer following improvement potentials:
• 8% for low efficiency base cases;
• 6% for medium efficiency base cases;
• 2% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

  Final (GWh/y) Primary (TJ/y)
US 1016 11153
Canada 268 3340
EU 889 8351
Thailand 115 1152
Vietnam 51 736
brazil 177 1973

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 612
Canada 134
EU 388
Thailand 60
Vietnam 25
brazil 26

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $3500  for S < 37 kW;
• US $7500 for 37 kW < S < 75 kW;
• US $10000 for 75 kW < S < 150 kW;
• US $20000 for 150 kW < S < 375 kW;
• US $25000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 136.6
Canada 140.6
EU 154.9
Thailand 111.6
Vietnam 110.1
brazil 107.7

Commercial
Sequencer Installation

This measure is estimated to offer following improvement potentials:
• 15% for low efficiency base cases;
• 8% for medium efficiency base cases;
• 2% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 2825 31009
Canada 745 9287
EU 2684 25217
Thailand 562 5647
Vietnam 213 3048
brazil 866 9667

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 1702
Canada 371
EU 1170
Thailand 291
Vietnam 104
brazil 127

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $0  for S < 37 kW;
• US $5000 for 37 kW < S < 75 kW;
• US $7500 for 75 kW < S < 150 kW;
• US $15000 for 150 kW < S < 375 kW;
• US $20000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 35.3
Canada 36.0
EU 31.7
Thailand 13.2
Vietnam 15.0
brazil 15.6

Commercial
Variable Speed Drives for Compressed Air Systems

This measure is estimated to offer following improvement potentials:
• 20% for low efficiency base cases;
• 15% for medium efficiency base cases;
• 5% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

  Final (GWh/y) Primary (TJ/y)
US 2268 24908
Canada 599 7460
EU 1985 18654
Thailand 253 2553
Vietnam 114 1629
brazil 392 4370

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 1367
Canada 297
EU 866
Thailand 131
Vietnam 56
brazil 57

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $12000  for S < 37 kW;
• US $20000 for 37 kW < S < 75 kW;
• US $40000 for 75 kW < S < 150 kW;
• US $70000 for 150 kW < S < 375 kW;
• US $100000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 164.1
Canada 166.9
EU 184.7
Thailand 123.9
Vietnam 122.3
brazil 121.9

Commercial
Improved End-use Efficiency

This measure is estimated to offer following improvement potentials:
• 12% for low efficiency base cases;
• 8% for medium efficiency base cases;
• 3% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 2491 27361
Canada 658 8195
EU 2180 20491
Thailand 371 3740
Vietnam 206 2945
brazil 574 6404

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 1502
Canada 327
EU 951
Thailand 193
Vietnam 101
brazil 83

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $1000  for S < 37 kW;
• US $1500 for 37 kW < S < 75 kW;
• US $2000 for 75 kW < S < 150 kW;
• US $7000 for 150 kW < S < 375 kW;
• US $10000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 40.4
Canada 40.4
EU 44.1
Thailand 15.4
Vietnam 13.6
brazil 17.9

Commercial
Size Replacement Compressor to Meet Demand

This measure is estimated to offer following improvement potentials:
• 18% for low efficiency base cases;
• 13% for medium efficiency base cases;
• 9% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

  Final (GWh/y) Primary (TJ/y)
US 1704 18709
Canada 450 5604
EU 1491 14011
Thailand 196 1967
Vietnam 88 1256
brazil 301 3367

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 
US 1027

Canada 224
EU 650
Thailand 102
Vietnam 43
brazil 44

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $12000  for S < 37 kW;
• US $25000 for 37 kW < S < 75 kW;
• US $40000 for 75 kW < S < 150 kW;
• US $70000 for 150 kW < S < 375 kW;
• US $120000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 212.7
Canada 219.8
EU 238.8
Thailand 155.5
Vietnam 153.9
brazil 154.4

Commercial
Replacing Compressed Air with Alternatives

This measure is estimated to offer following improvement potentials:
• 20% for low efficiency base cases;
• 13% for medium efficiency base cases;
• 3% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 3479 38196
Canada 918 11439
EU 3045 28605
Thailand 467 4703
Vietnam 210 3003
brazil 722 8051

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 2096
Canada 456
EU 1327
Thailand 243
Vietnam 103
brazil 106

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $2000  for S < 37 kW;
• US $4000 for 37 kW < S < 75 kW;
• US $7000 for 75 kW < S < 150 kW;
• US $12000 for 150 kW < S < 375 kW;
• US $15000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 49.9
Canada 51
EU 56.3
Thailand 30.3
Vietnam 30
brazil 30.4

Numerous case studies across all U.S. industries estimate the average payback period for this measure to be only slightly higher at less than 9 months.

Commercial
Reducing Pressure Drop in Connections and FRLs

This measure is estimated to offer following improvement potentials:
• 20% for low efficiency base cases;
• 15% for medium efficiency base cases;
• 10% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 951 10446
Canada 251 3129
EU 832 7823
Thailand 139 1395
Vietnam 63 891
brazil 214 2388

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010):

US 574
Canada 125
EU 363
Thailand 72
Vietnam 31
brazil 25.1

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $  for S < 37 kW;
• US $ for 37 kW < S < 75 kW;
• US $ for 75 kW < S < 150 kW;
• US $ for 150 kW < S < 375 kW;
• US $ for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 55.7
Canada 57.9
EU 68.5
Thailand 21.6
Vietnam 20.9
brazil 31

Commercial
Installing Zero-Loss Condenser Drains

N/A

Commercial
Opimizing Compressor Intake Conditions

This measure is estimated to offer following improvement potentials:
• 2% for low efficiency base cases;
• 1% for medium efficiency base cases;
• 0% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

 
  Final (GWh/y) Primary (TJ/y)
US  203 2227
Canada 54 667
EU 185 1731
Thailand 53 535
Vietnam 24 341
brazil 82 915

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 122
Canada 26
EU 80
Thailand 27
Vietnam 11
brazil 12

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $150  for S < 37 kW;
• US $400 for 37 kW < S < 75 kW;
• US $1000 for 75 kW < S < 150 kW;
• US $2000 for 150 kW < S < 375 kW;
• US $3000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 87.3
Canada 86.9
EU 87.6
Thailand 24.6
Vietnam 24.8
brazil 28.1

Commercial
Reducing Excessive Pressure Drop in Distribution Piping

This measure is estimated to offer following improvement potentials:
• 5% for low efficiency base cases;
• 3% for medium efficiency base cases;
• 0.5% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

 
  Final (GWh/y) Primary (TJ/y)
US  594 6521
Canada 157 1953
EU 520 4884
Thailand 79 801
Vietnam 35 511
brazil 123 1371

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 358
Canada 78
EU 227
Thailand 42
Vietnam 17
brazil 18

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $2000  for S < 37 kW;
• US $3000 for 37 kW < S < 75 kW;
• US $6000 for 75 kW < S < 150 kW;
• US $10000 for 150 kW < S < 375 kW;
• US $12000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 105.5
Canada 107.3
EU 121.5
Thailand 62.4
Vietnam 61.3
brazil 62

Commercial
Isolating High Pressure & Intermittent High Volume Uses

This measure is estimated to offer following improvement potentials:
• 5% for low efficiency base cases;
• 3% for medium efficiency base cases;
• 2% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

  Final (GWh/y) Primary (TJ/y)
US 573 6292
Canada 146 1818
EU 484 4548
Thailand 76 764
Vietnam 35 488
brazil 129 1438

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 346
Canada 72
EU 211
Thailand 39
Vietnam 17
brazil 19

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $2000  for S < 37 kW;
• US $4000 for 37 kW < S < 75 kW;
• US $5500 for 75 kW < S < 150 kW;
• US $8500 for 150 kW < S < 375 kW;
• US $14000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 108.8
Canada 113.9
EU 129.1
Thailand 75.9
Vietnam 74.7
brazil 60

Commercial
Reconfiguring Branch Header Piping

This measure is estimated to offer following improvement potentials:
• 4% for low efficiency base cases;
• 3% for medium efficiency base cases;
• 1%for high efficiency base cases.

Electrical and primary energy savings potential of this technology for different countries is estimated as following (UNIDO, 2010):

 
  Final (GWh/y) Primary (TJ/y)
US  553 6073
Canada 151 1885
EU 501 4711
Thailand 77 778
Vietnam 35 497
brazil 107 1203

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 333
Canada 76
EU 218
Thailand 40
Vietnam 17
brazil 15

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $2000  for S < 37 kW;
• US $3000 for 37 kW < S < 75 kW;
• US $6000 for 75 kW < S < 150 kW;
• US $10000 for 150 kW < S < 375 kW;
• US $ for15000 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following (UNIDO, 2010):

US 110.9
Canada 113.2
EU 124.8
Thailand 49.5
Vietnam 48.7
brazil 58.1

Commercial

Compressed Air Systems Publications

Compressed Air Systems Case Studies