Compressed air systems on the other hand are at best 50% efficient in many facilities. A new 100 hp compressor represents an expenditure of $30,000-$50,000 depending on type and manufacturer. At $.05 per kwh, a 100 hp compressor operating at full load for one month will consume $36,300 of electricity in one year. When a compressor is unloaded, it still consumes about 30% of the total power rating of the motor. Our same 100 hp compressor operating 65% of the time fully loaded and 35% of the time unloaded will still consume $27,400 of electricity in one year.
A simple plan to reduce compressed air costs is a follows:
Eliminate Timer Drains-Timer drains do not operate! It is impossible to set a frequency and duration timer to meet all the varying humidity conditions which exist. If timer drains are set for one moment in time at specific weather conditions, they will either back up condensate or waste air. In virtually all applications they waste air to the tune of $650.00 per year per drain. Use a Zero Loss Drain.
Reduce Air Pressure-Lowering air pressure by 2 psig will cut operating costs 1%. As an example, a reduction in plant air pressure from 120 psig to 100 psig will cut electrical costs 10%. Clogged and ineffective filters combined with undersized lines are major contributors to consuming pressure drop. Undersized compressed air filtration and drying equipment also consumes pressure drop. Insert accurate pressure gauges and measure your system pressure drop.
Air Leaks-A single 1/8” hole at 100 psig will waste $2,095 of air in one year. Common leak points are hoses, tubes and fittings, timer drain valves, manual condensate drains left open or cracked, and pipe joints. Leaks can be detected by ultrasonic sound guns or by shutting down plant areas and noting the time required for the pressure to drop 5 psig. Lowering air pressures will also drop leakage rates. Large air systems might also include flow measurement devices to permit tracking of unexplained increases in air flows which might indicate leak points.
Improper Uses of Compressed Air-Most air compressors will produce about 4 cfm of air per horsepower consumed. Most blowers will produce about 16 cfm of air per horsepower. Vacuum systems are much more effective for removing debris from production systems than blowing the dust into the air. Blowers are more efficient for drying and material transport. Using a blower in place of plant compressed air will cut operating costs as much as 75%.
Air Quality-The requirements for air quality can vary from jack hammer air to breathing air. The four general levels include plant air, instrument air, process air, and breathing air. Using point of solution equipment to condition air to meet your application requirements might be more cost effective than treating all plant air to your most rigid requirements. Simple cost effective solutions include coalescing filters along with point of use refrigerated and desiccant dryers.
We don’t sell air compressors. We focus our efforts on maximizing your current compressed air system while reducing your operating costs. We focus on recommending inexpensive solutions whenever possible with paybacks of 2-3 months.
If your compressed air system is costing you money and you are not satisfied with current operations, consult us for details on an air quality and system survey. Cost of the survey and report is inexpensive and we offer a 100% money back guarantee if not satisfied with the results. Call for complete details.
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