Keys to Energy Savings
There are many kinds of energy-intensive processes, from cooking, dishwashing, and cleaning of clothes, to office work, welding, and painting automobiles. They all rely on energy powered equipment that transforms or 'processes' material in some way. No matter what the specifics of your use of process energy, the following rules may be the key to significant energy savings:
- Turn machines off whenever possible.
- Adjust controls to a temperature, speed, or the setting that uses less energy but still does the job properly.
- Clean, tune and adjust, lubricate, replace worn parts, and otherwise maintain the equipment.
- Manage your electricity use to avoid high demand changes.
- If cost-justified, increase your energy efficiency by:
- replacing old or inefficient equipment
- installing new automatic controls
Motors
New motors are available in standard and high efficiency models. A high-efficiency motor will cost more than a standard one, but electricity savings can quickly pay back this cost difference if the motor is used a lot. Rewinding a burned out motor often reduces its efficiency. When energy costs are considered, it is often a better investment to buy a new high efficiency motor. How to compare the efficiency of different motors: Motor efficiencies vary from manufacturer to manufactures, so look for the 'Average Nominal Efficiency' rating on the motor nameplate. Average Nominal Efficiency refers to the average full-load efficiency value found from testing a sample of motors of the same motor model. Below is a comparison of standard vs. premium motor efficiencies:
Electric Motor Efficiencies
| | Avg. Nominal Efficiency |
|
| Motor HP Rating | Standard Motor | Efficient Motor |
| 1 | 73% | 83% |
| 1.5 | 75% | 83% |
| 2 | 77% | 83% |
| 3 | 80% | 86% |
| 5 | 82% | 87% |
| 7.5 | 84% | 88% |
| 10 | 85% | 89% |
| 15 | 86% | 90% |
| 20 | 87.5% | 90.5% |
| 25 | 88% | 91.5% |
| 30 | 88.5% | 92% |
| 40 | 89.5% | 92.5% |
| 50 | 90% | 93% |
| 60 | 90.5% | 93% |
| 75 | 91% | 93.5% |
| 100 | 91.5% | 94% |
| Source: 'How to Reduce Your Energy Costs', Advantage Publications and Insights, Boston, MA 1996 |
The higher the efficiency rating, the more efficient the motor and greater the savings. You will find on the market motors with higher nominal efficiencies than the ones listed above;- look for them. A small gain in efficiency can produce substantial operating savings over the life of a motor.
Compressors
Your compressed air system may be costing you energy dollars in the form of 'stand-by' losses - keeping air under pressure when it's not needed - or by leaking at various points in the system. Or you may be running it more than you need to. In addition to turning off the air compression when not in use, you can save additional energy by:
- Fixing Leaks
Fix leaks in hose connections, shutoff valves, pipe connections and flanges, in hoses and clamps, and in worn air cylinders. Your best changes of detecting leaks is when noise levels in the area are low - after work, at lunch, or during a coffee break. - Using the Right Nozzles
If you use compressed air to clean or blow away excess material in the manufacturing of a product, make sure you use a nozzle that concentrates and controls the stream of air. Using a hose without a nozzle, or a nozzle with too large an opening, will waste lots of compressed air - an energy dollars. - Using Outside Air
Many air compressors are located in boiler rooms or mechanical rooms and must compress warm inside air. If you install an outside air intake in the exterior wall, the compressor will be able to use cool outside air, which takes lass energy to compress.
