The Issue with Oversizing

When it comes to compressed air systems, there’s a common misconception that bigger is better. However, running an oversized compressor can contribute to a host of issues that compromise both the equipment and your operational efficiency. At Focus Industrial, we recently had a new service customer reach out about a serious compressor failure, and the root cause was directly linked to oversizing.

Oversizing Leads to Failure

A new customer contacted us with a major issue in their system. Their 11kW Ingersoll Rand screw compressor had unexpectedly shut down, and upon closer inspection, we identified that the compressor was significantly oversized for the application. The oversized unit had caused excessive moisture build-up inside the machine, which eventually led to rust forming on the screws.

Due to the compressor’s size, it rarely ran long enough to reach the optimal temperature needed to evaporate moisture. When a compressor is oversized, it tends to idle or run on lighter loads more frequently. This results in the compressor not heating up sufficiently to vaporise any accumulated moisture, allowing it to linger and settle inside the unit. In this case, over time, the screws rusted, which is both costly and disruptive. This customer faced unplanned downtime, and without immediate intervention, the damage could have required a full screw element replacement.

Why Oversizing Causes Issues

While it might seem that opting for a larger compressor will provide ample capacity, the reality is that oversizing leads to several long-term problems:

• Moisture Accumulation and Rust: Just as we saw with the Ingersoll Rand compressor, oversizing can cause moisture to remain in the system. The lack of sufficient heat prevents proper evaporation, allowing water to pool inside the compressor. Over time, this can cause rust and corrosion on crucial components, including screws and bearings, compromising the machine’s longevity and leading to costly repairs.
• Increased Wear and Tear: Because an oversized compressor often cycles on and off or runs at low loads, it experiences more wear and tear on essential components. This includes the motor and the screw elements, which are not designed to handle constant cycling. The end result can be frequent breakdowns and premature part replacements.
• Reduced Efficiency: A compressor that doesn’t match your specific air demand will end up wasting energy. In the case of fixed speed compressors, oversizing often means the compressor is running at full speed when it isn’t needed, wasting electricity. Similarly, a variable speed drive (VSD) compressor that is oversized will consume excess energy to produce compressed air that’s not required, resulting in increased operational costs.
• Higher Operational Costs: Not only do oversized compressors cost more upfront, but they also incur higher long-term costs due to increased energy usage and maintenance requirements. Components wear out faster, and rusted elements may require more intensive (and expensive) repairs or replacements, as we observed with the rusted screws in our customer’s unit.

Choosing the Right Compressor for Your Needs

The importance of having the right-sized equipment for your operations cannot be understated. We encourage businesses to conduct thorough assessments before investing in a new compressor. This includes analysing factors like peak usage, duty cycles, and any fluctuations in operational patterns. Using tools like compressed air audits and flow metres can precisely gauge your needs and recommend the optimal solution.

Proper sizing not only prevents moisture issues and rust but also extends the life of your equipment and reduces your energy footprint. Our team offers consultations to help you navigate these decisions, ensuring you invest in a compressor that matches your needs.

Helping You Find the Right Fit

If you’re concerned about whether your compressor is sized correctly, it may be time to have it evaluated. At Focus Industrial, we specialise in guiding businesses through this process, helping you avoid the costly mistakes associated with oversizing. We provide in-depth assessments and can recommend whether a fixed speed or VSD compressor option will best meet your unique air demands.

Don’t let an oversized compressor lead to rusted components, wasted energy, and unexpected repairs. Contact us today for expert guidance and to find a solution that fits your business needs. Sizing your compressor correctly is the first step to achieving a reliable, cost-effective, and efficient compressed air system that supports your long-term goals.