Supported by

EIE/04/246/S07.38678

 

 

BESS - Benchmarking and Energy management Schemes in SMEs

 

Horizontal Energy Efficiency Measurement List

 

PRODUCTION PROCESSES

 

Thermal Energy

 

Heat Generation

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Reduce excess combustion air to minimum

1. CO2/O2 measurement

2. Maximise completeness of combustion

2. Soot/CO measurement

3. Maintain boiler cleanliness (soot/scale)

3. Monitor for rise in flue gas temperature

4. Repair (replace) boiler insulation

4. Periodic inspection of boiler insulation condition.

5. Insulate feedwater tank – cover tank

5. Check possible feedwater temperature losses

6. Insulate condensate return lines

6. Check possible heat loss from condensate return lines.

7. Optimise quality of make-up water and feedwater

7. Monitor quality of make-up water and feedwater: hardness, acidity, O2.

8. Minimise blowdown

8a. Monitor concentration of dissolved solids in boiler water.

8b. Improve blowdown controls

9. Maintain nozzles, grates, fuel supply pressure/temperature at manufacturers’ specifications

9a. Ensure specifications are available and in use.

9b. Regular check and resetting/maintenance.

10. Maximise combustion air temperature

10. Draw air from highest point in boilerhouse.

11. Reduce steam pressure where it exceed system/process requirements.

11. Check system/process needs; adjust controls.

12. Use duct for intake of warmer combustion air

12. Install duct from combustion air intake to higher parts of room.

13. Install an automated gas leakage detector.

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14. Repair leaks in steam pipework.

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Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. For rapidly varying demand, convert one or more boilers to live accumulator (buffer tank).

1. Monitor/evaluate demand change patterns.

2. Alter controls to �High-Low-Off� or �modulating-Low-Off�

2. Monitor/evaluate demand change patterns.

3. Install flash steam heat recovery

3. Consider in large capacity situations with high (continuous/frequent) blowdown.

4. Improve combustion controls.

4a. Provide adequate heat input to meet demand.

4b. Minimise fuel/pollution.

4c. Protect personnel/equipment.

5. Waste heat recovery

5a. Economizer

5b. Air heater (recuperator)?

6. Install boiler blowdown heat recovery.

6. Consider in large capacity situations with high (continuous/frequent) blowdown.

7. Use process integration

7. Couple process units that have significantly different heat requirements (i.e. low-pressure steam leaving a high-pressure steam consuming production process can be used for a process requiring low-pressure steam).

 

Heat Distribution

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Repair/replace faulty insulation

1. Pipework insulation – especially around valves.

2. Repair inefficient steam traps/drains. valve spindles etc.

2. Regular checks for leaks throughout the system.

3. Insert valves to isolate �periodic-use� items in system.

3. Check system for periodic (e.g. seasonal, nightly) items (e.g. space heaters).

4. Remove/isolate �dead-legs� and redundant Pipework

4. Check for dead-legs and redundant piping.

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Replace steam traps/drains with more efficient designs.

1. Monitor efficiency of, and heat losses from existing traps.

2. Replace or increase insulation

2. Check existing insulation; estimate heat losses in system.

3. Maximise condensate returns.

3. Measure �discarded� heat from condensate.

4. Redesign system to minimise pipe runs.

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5. Generation pressure reduction.

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Heat Utilization a) process

 

Energy Saving Opportunity

Action to Check

1. Plant insulation

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2. Local burner efficiency

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3. Maximise heat transfer rate

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4. Improve controls (e.g. thermostats)

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5. Consider alternative energy source

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6. Ensure plant at high load factor

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7. Eliminate uneconomic �hot standby� periods

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8. Recycle waste heat to process

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9. Recover heat, for use elsewhere

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10. Train all staff to operate manual controls and to watch for energy saving opportunities.

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Heat Utilization b) space heating

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Use heat only when area is occupied

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2. Set thermostats to minimum for comfort

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3. Minimise loss of hot air

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4. Clean and effective heaters

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5. Maintain pipe insulation in unheated areas

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6. Check condensate traps

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7. Vent air from hot water systems

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8. Time switches

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9. Manual controls where appropriate

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Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Install more/more efficient thermostats

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2. Use motorized valves to divide building into different zones

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3. Air curtains

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4. Change energy source

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5. Change heating system – where:

Β InsulationΒ Β Β Β Β Β Β  VentilationΒ Β Β Β Β Β Β Β Β  Use

Β Β  GoodΒ Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β  HighΒ Β Β Β Β Β Β Β Β  Radiant Heat

Β Β  PoorΒ Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β Β  LowΒ Β Β Β Β Β Β Β  Convective Heat

 

6. Improve building insulation

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Electrical Energy

 

Motors

 

Energy Saving Opportunity

Action to Check

1. Try to ensure that motor capacity is not more than 25% in excess of full load.

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2. Install motor controllers (voltage, power factor and fixed speed controllers).

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3. Build in �soft-start� facilities.

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4. Install variable speed drives

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5. Install high efficiency motors

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Compressed Air

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Switch off whenever possible.

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2. Install low-cost solenoid valves on air supply lines to individual machines. Switch off compressed air supply as soon as machine is switched off.

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3. Clean air intake filters regularly

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4. Use lowest possible operating pressure. Reduce pressure locally if possible.

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5. Use lowest air intake temperature possible.

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6. Fit 2-speed motors.

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7. Fix leaks

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8. Check on correct pressure setting regularly.

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Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Fit a small (jockey) compressor to meet off-peak demand.

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2. Duct air intake to ensure coolest possible.

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3. Fit air flow and kWh meters to monitor power and air use.

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4. Install modern controls on multi-compressor installations.

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5. Fit a standard heat recovery unit.

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6. Air pre-cooling.

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7. If some users are using low pressure air (2.5 – 3 bar), install two separate systems.

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8. Use frequency control for compressor.

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9. Use an individual compressed air supply for special applications.

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10. Replace pneumatic tools be electrical tools

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Vacuum

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Switch off whenever possible.

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2. Regular maintenance is necessary to maintain pump efficiency and prevent breakdown, especially when the vacuum-space contains condensing vapours;

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3. Fix leaks

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Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Fit a standard heat recovery unit.

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2. Use a central vacuum system with several delivery points

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Refrigeration

 

Design measures

Energy Saving Opportunity

Action to Check

1. Group refrigeration cells according to temperature.

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2. Use an integrated plant layout – optimise use of evaporators or condensers (i.e. remove obstacles)

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3. Limit energy losses through open doors

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Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Switch off lights, fans, pumps. etc., when not required.

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2. Repair damaged insulation/seals.

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3. Check for refrigerant contamination.

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4. Check for scaling on condenser and evaporator surfaces.

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5. (Multi-compressor systems); set controls to activate minimum number of compressors.

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6. Monitor timing and duration of defrost cycles. Defrost on demand rather than at fixed intervals.

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7. Use load rescheduling (e.g. cool at night) where maximum-demand tariffs are in operation.

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8. Minimise cooling space by installing removable plastic screens or panels or by filling cooling space with polystyrene foam blocks

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9. Switch off evaporator fans when compressor is off

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10. Regulate condenser pressure (and therefore temperature)

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11. Delayed start-up of compressors. Initially, only start-up of ventilation.

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12. Increase the evaporation temperature.

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Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Install kWh meters and instrumentation to monitor equipment and cold room.

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2. Install an energy management system which analyses operation of the whole refrigeration system.

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3. Use effective insulation and sealing.

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4. Install efficient electronic expansion valves. Avoid �head pressure control� where possible.

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6. Recovery of waste heat at the condenser

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7. Automatic bleeding of refrigerant to remove any penetrated air

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8. Install frequency control (i.e. VRF) on chiller compressor.

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9. Install high efficiency or 2-rev electromotor on evaporation fan

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10. Build a cooled front space for refrigeration units.

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11. Use hot refrigerant gas from the compressor for the initial stages of the defrosting cycle.

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12. Use excess heat from other production processes for the production of cooling using adsorption/absorption cooling.

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PRODUCTION BUILDINGS

 

 

Lighting

 

Energy Saving Opportunity

Action to Check

1. Use the most efficient lamps consistent with required illumination levels and colour rendering.

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2. Use the light output from lamps efficiently.

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3. Maintain lamps and fixtures clear of light-blocking dust and dirt.

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4. Switch off lights where lighting is not needed.

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5. Consider automatic control of lighting (time clocks and/or photo cells).

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6. Make the best use of daylight.

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7. Avoid the absorption of light by the surroundings (light-coloured wall, ceilings, and floors).

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8. Replace lamps which have exceeded their rated life.

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9. Use �switch-off� and �save-it� stickers as a tool of good housekeeping.

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10. Consider new technologies in order to reduce installation cost, such as infrared switching.

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11. Divide the lighting system of a large space into several independent lighting groups.

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12. Use presence detection switches

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13. Use a lighting system that is continuously variable (e.g. high-frequency fluorescent lighting).

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Building skin

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

-

-

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1.Thermal insulation of floor

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2.Thermal insulation of walls

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3.Thermal insulation of roof

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4. Use of double-glazed or solar shading glass windows

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Central Heating

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

1. Use a weather dependent control to regulate the temperature of the boiler water in relation to the outside temperature.

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2. Install an advanced timer for the boiler operation schedule.

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3. Insulate pipework

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4. Insulate hot water storage tanks

 

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Divide large interior spaces into smaller areas.

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2. Use radiation heating in cases where large ventilation rates are required.

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3. Use displacement ventilation in the case where the heated indoor areas are higher than 6 meters.

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Ventilation system

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

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-

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Heat recovery of exhaust air using a rotary wheel.

 

2. Reduce the amount of ventilation air as much as possible by the installation of:

Β·          Timer switch;

Β·          Occupancy sensor

Β·          Air quality;

Β·          Frequency control on the fan motor

 

3. Prevent infiltration through door openings with:

Β·          Thermal insulation

Β·          Draught curtains

Β·          Air cushion

Β·          Automatic door

Β·          Slip door

Β·          Rubber seal between door and doorpost instead of brushes or no sealing.

 

 

Exhaust systems

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

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-

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Use local exhaust ventilation systems. The purpose of a local exhaust system is to remove the contaminants (dust, fume, vapour etc.) at the source.

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2. Some options for improving the efficiency of exhaust systems are:

Β·          Frequency control on the electromotor of the fan

Β·          Close exhaust points that are not in use.

Β·          Start up the exhaust system with all exhaust points closed.

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Air-conditioning

 

Low-cost / short term opportunities

Energy Saving Opportunity

Action to Check

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-

Higher cost / longer term opportunities

Energy Saving Opportunity

Action to Check

1. Use thermal energy storage systems (i.e. ice banks)

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2. Use shading devices for windows.

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