Nothing in life comes free. Not even air, unfortunately. Once you have purchased and set up your commercial air compressor, there are still operating and running costs to deal with.
To avoid electricity costs overrunning utility bills, it’s important to watch how much energy the air compressor is using. While our Kaesar air compressors are rated for the highest efficiency possible, it is still a good idea to implement compressed air energy savings in other ways.
Why Compressed Air Energy Saving is Vital
In Ontario, the cost of electricity varies from 0.08 CAD per kWh on off-peak hours to 0.17 CAD per kWh during the peak. Unless you are doing most of your work in the evening, you will be running the compressor through the on-peak hours.
Taking into account the mid-peak hours and seasonal differences, we can assume it averages out to approximately 0.14 CAD per kWh.
This value will help us explain why compressed air energy saving is so important.
1 HP equals 0.75 kWh. There is also the additional factor of efficiency. An Air Compressor will not convert 100% of the electricity into compressed air. A small amount will be lost due to inefficiencies and friction.
When you run a relatively lightweight 5 HP air compressor for 8 hours, the theoretical energy cost comes out to 3.75 kWh x C$0.14 x 8 Hours. If the compressor is 80% efficient, then it will cost you C$4.2 / 0.80 = C$5.25 over the whole day. In a five-day work-week, that would be C$26.25.
These are just theoretical numbers. In reality, there are further inefficiencies in the air compressor that could raise the operating costs even further.
When using a bigger air compressor, or a less efficient one, the costs will build up quickly. To avoid wasting energy when it is already so expensive, here are nine compressed air energy-saving tips to put into action.
1. Only purchase high efficiency air-compressors
As we just demonstrated, efficiency can affect the price significantly. Running an 80% efficient compressor increased the overall running costs by 25%.
Our top-quality DV and Kaesar air compressors operate at 90% or higher efficiencies. The overall efficiency depends on the design of the compressor. The quality of the components and lubricant used also affect it.
As expected, a higher-quality compressor with better efficiency will come at a cost. It is up to the user to determine if the increased initial cost is worth the savings in the long term. If the user does not use the air compressor on a regular basis, then it may take years to recuperate the ROI from choosing a more efficient compressor over a less efficient one.
Overall efficiency is massively important for rotary air compressors, which may operate non-stop for days. A piston-based air compressor usually runs intermittently, so the general efficiency is not as important.
2. Search for and fix any air leaks
Air leaks are probably the number one cause of inefficiency and waste in Air Compressors.
Creating air-tight seals in a device with lots of moving parts is difficult. Almost all air compressors have a few gaps or structural imperfections. When the air is compressed into such high pressures, it can quickly push through these spots.
Some air compressors can lose up to 30% of their throughput through leaks. This means that the device simply has to work harder or be run longer in order to get the same pressure and volume of output air. This raises energy costs significantly.
If you lose 25% of the air to leaks, then to achieve 100% of the expected throughput, the monitor has to run the compressor at a higher HP. For a 5 HP compressor, it may have to run it at 5 HP / 0.75 = 6.7 HP. If you want compressed air energy savings, you need to stop as many leaks as possible.
Leaks are manageable without extensive repair work. The first step is to detect the leaks. This can be done using an ultrasonic leak detector.
When high-pressure air escapes through such a small hole, it makes an extremely high-pitched sound. The sound is inaudible to the human ear. However, an ultrasonic leak detector can detect this sound and display it to the user. Using one is extremely simple – just hold the probe close to the compressor from different directions.
After detecting leaks, the next step is to carry out repairs. Typically, this involves replacing different parts or tightening the fittings and seals. If the valve, pipes or tank is leaking, they must be replaced entirely.
Generally, replacing individual parts is much more economical than replacing the entire device. If you believe your air compressor has significant leaks, contact us for replacement components.
3. Check out alternative lubricants
Lubricants are an essential component of air compressors. They keep rotary devices spinning smoothly and allow the piston to push compressed air while remaining airtight.
The specific type and quality of lubricant determine how little friction there is. As you know, friction generates heat and slows down moving parts. To compensate for this, the motor needs to run at a higher power. This raises inefficiency and generates even more heat. The efficiency loss in the motor compounds any efficiency loss in the piston and pipes.
High-quality oil-based lubricants are the most effective, but they can introduce impurities into the compressed air. Other lubricants are less efficient but do not affect the air quality. Some high-end oil-based lubricants will not affect the air quality, but the price is a factor.
Choosing the right lubricant is an important step for compressed air energy saving.
4. Decrease the operating pressure
So far, all the calculations regarding operating costs and efficiency assume maximum pressure. Most air compressors operate at up to 150 PSI.
But is it really necessary? Consider how much pressure your tools require. If you are only using an air-powered Drill at the moment, it requires a maximum of 90 PSI and 3-5 CFM. If your compressor outputs 30 CFM at 150 PSI, most of the output is going to waste.
Even with a 90 PSI drill, it may not actually require 90 PSI. It may work optimally at 80 or 85 PSI.
Decreasing the operating pressure is a great way to reduce power use. Just be careful when decreasing it. A large, sudden drop could cause damage to your equipment. We suggest reducing it by 1-2 PSI at a time and testing it for a while. If it is stable at the lower PSI, you may decrease it further. Remember to adjust and optimize the CFM at the same time as well.
5. Optimize mechanical connections and layout
This may not be applicable to most home uses of air compressors. It is mainly for commercial and industrial air compressors.
Multiple tools can be powered by one air compressor. They will be attached via pipes. The layout of the pipes and the way they are attached can affect the flow of air.
For instance, consider a T-junction for combining the output of two air compressors. The air comes in from opposite ends of the top half of the ‘T’. If they met directly, they will clash against each other. This creates turbulence and causes a decrease in pressure.
This issue could be alleviated by adding some extra fittings. One side of the ‘T’ could approach at the normal angle, while the other side could pass through another short pipe. It could merge into the ‘T’ in the bottom half at an angle, reducing turbulence.
As a general rule of thumb, avoid right-angled or sharp bends. Merging or splitting an air stream is best done at an angle and using valves.
6. Reduce the temperature of incoming air.
According to particle physics, colder air has less energy. When it has less energy, individual particles move around more slowly and take up less volume.
Hence, colder air is easier to compress. This should be good news for most, given that there is no shortage of cold air here in Canada. Remember that the compressor will generate heat and warm up the air around it. So it’s a good idea to place the intake of the compressor in a cool location where there is a flow of air.
Air at 30 °C takes about 3% more energy to cool compared to air at 20 °C. The difference may not seem like much, but like all other factors, it contributes in the long run.
One example of a good location would be the intake facing outdoors. For most of the year, the air should be reasonably cool. Having the intake outside will prevent the air around the compressor from heating it up.
If the compressor has to be run indoors, such as on a workshop or factory floor, air conditioning is a good idea. While air conditioning introduces extra costs, it keeps the work environment comfortable. It will reduce any thermal issues around the compressor and keep operating efficiency higher.
7. Consider the exact purity or quality of air needed
The quality of the output air can affect efficiency. The more stringent your requirements, the more expensive it may be.
The lubricant plays a significant part in determining the quality of the air. There are also other factors at play.
For instance, moisture. Damp and moist air is harder to compress. As it is heavier, it decreases the flow rate and forces the motor to work harder. Additionally, when compressed air is released water droplets in the air may condense and liquefy, introducing water into your air compressor’s internals. To work around this issue, air compressors have a drain for removing the water.
8. Purchase the correct air compressor for your needs.
With some good planning and forethought, you can decrease the cost of electricity used.
Consider that electricity is cheaper during the off-peak hours. However, at this time, you are most likely finished with work for the day or still asleep. During the peak hour, you may need 3-4 hours’ worth of compressed air.
Most piston-based air compressors have a tank for storing air temporarily. You could turn the compressor on before the peak hours and take advantage of off-peak billing. The air would be stored in the tank, released throughout the day.
A compressor with a larger tank is more expensive. Again, it comes down to deciding between a larger initial expense and small savings in the long run.
With Rotary air compressors, they are run continuously for long periods of time. So it’s important to focus on improving efficiency and performing regular maintenance instead.
9. Think about alternatives to compressed air
So far, you have been reading all about compressed air energy savings. But we have not mentioned the most effective way yet.
Even if we are trying to sell you air compressors, it’s time for some honest truth. Air compressors require about 8x as much electricity to power a device compared to direct electric power. If electric-powered tools in conjunction with smaller, home hand-held air compressors work, then there is no need to spend on a power-hungry air compressor.
However, air compressors offer ouch higher power output for a portable device. They are less noisy when the tool is being operated. They are safer and more accurate. If all these benefits are useful to you, then an air compressor would be preferable.
Energy wastage is one of the big problems with modern society. Climate change and fuel shortage issues are all due to the amount of energy we require. That’s why targeting compressed air energy saving is important.
Primarily, it decreases how much you need to spend on electricity bills. You could see savings up to 30-40% after applying all the tips mentioned here. And as a secondary bonus, you are contributing to saving the world.
Remember to check our products page for the most efficient commercial air compressors, dryers and other equipment.