The Energy Services Act is a key piece of legislation in Germany that aligns with the EU Energy Efficiency Directive. It mandates that large enterprises conduct regular audits to improve energy efficiency and reduce overall consumption or potentially face fines up to €50,000.
Such legislation drives technology innovation and increases the adoption of efficient machinery, IoT-based monitoring, and automated systems to address audit findings and energy goals. For compressed air systems, this includes implementing intelligent control solutions to integrate data sources and identify opportunities for energy savings.
According to a study by Radgen and Blaustein, compressed air systems can account for 10% of Germany’s industrial electricity consumption. Manufacturers are well aware that such consumption includes air losses due to leaks at joints, valves, worn hoses, and other components throughout the system. Without regular monitoring and maintenance, leaks can remain undetected, continuously wasting the system’s energy and driving up costs.
“In many cases, leakage is more than 30% of the compressed air,” said Patrick Schuckenböhmer, sustainability coordinator at Boge Kompressoren. “Unlike water or oil leaks, air leaks leave no marks on the floor. The cost of the electricity generated by leakage usually disappears in the electricity bill for the whole factory, and as long as there is enough compressed air to work with, no one complains. But the cost can be significant, even in smaller companies. If a compressor with 25 kW electric power consumption is running 350 hours per year just because of leakage, at a price of €0.2 per kWh of electricity, this adds up to around €1,750 per year.”
The Radgen and Blaustein study shows that approximately only 45% of compressed air consumption meets air system demands. The majority of the rest is from leakage and unnecessary excessive usage.
Oftentimes, users try to compensate for air losses while still meeting air demands by operating systems at higher pressures. However, as Schuckenböhmer put it, “an air pressure too high causes losses; a pressure too low, even for a short time and only in one branch of the compressed air system, can cause damage.”
Larger manufacturers typically have a superordinate control system that monitors and optimizes air demand and related parameters in multiple compressed air systems. However, in small and medium-sized companies without superordinate control, measuring leakage remains a manual process. Boge developed and integrated a leakage monitor in the control of its compressors, especially for these systems, to manage what it calls “energy gobblers.”
“In smaller companies, the person responsible for the compressed air system has probably heard of energy saving and leakage, but does not know how much leakage in the compressed air system costs. The leakage monitor can show them,” said Schuckenböhmer. “The idea behind the leakage monitor is simple: If there is no useful air demand within a specific time slot, then all air demand during this time is leakage. Then, you can sit next to the compressors for a few hours with a stopwatch, count the running times when air is being compressed, add up the compressed air, and calculate.”
Schuckenböhmer provided an example: 18 min of operation of a 2 m³/min compressor in 3 hr with no useful air demand results in 18 min / (3 * 60 min) * 2 m³/min = 0.2 m³/min leakage. Since leakage is usually almost the same throughout the year, manufacturers can calculate the cost per year.
“The downside of this method is that nobody likes to sit next to the compressors for a few hours at night or on a Sunday,” he said. “So, this counting task is done by the Base and Focus 2.0 controllers, except the Focus versions for scroll compressors or Boge turbocompressors. It has been part of the standard control software since 2012, and older controllers of these types can be upgraded with this software.”
Additionally, interlocking control, such as the Airtelligence Provis 3, helps make the entire compressed air management efficient and adaptable. The software integrates an unlimited number of components and, based on requirements, determines the optimal compressor configuration for a specific time during operation. The smart tool is particularly suitable for highly fluctuating compressed air requirements and mixed compressor combinations. It also continuously optimizes energy consumption, where a 1-bar reduction saves as much as 10% in energy costs.
Another important area where companies can lower energy costs is heat recovery. Up to 94% of the energy consumed during compressed air generation can be reused as heat, with an average payback period of four months. In this process, Boge diverts the waste heat from the compression process, specific to each compressor. It can then be used to heat rooms or water, for example. Compressors manufactured by others can also be retrofitted with Boge’s heat recovery system.
“The two simplest systems, which are used most often, are an air duct that brings warm cooling air from a compressor into a large room of the factory in winter, without any sensor, and a heat exchanger that uses the waste heat from the compressor to heat the water of the heating system in a factory, coming back from its heating task with a lower temperature and going into the boiler of the central heating, giving the temperature necessary for heating the factory. There is no sensor or control system. The waste heat is transferred to the hot water, if available, and the central heating boiler provides the additional heat. Of course, more complex systems are possible,” said Schuckenböhmer.
Boge
boge.com
