Why a more expensive filter is often the cheaper choice

Filters come in many sizes of quality and price. How do you make the right choice and why is it often the better option to go for quality and not just pay attention to price? In this blog we will tell you all about what makes the difference and how you ultimately save by choosing the A-brands.

The basic properties of a filter

The purpose of a filter is to remove contamination. Whether you are talking about an air filter, oil filter or hydraulic filter, the principle of filtration is always the same. You want to remove particles from the dust you pass through the filter to prevent them from resurfacing further down your system or engine and causing greater damage. Basically you can say that a filter has three basic properties; capacity, efficiency and reduction.

Filter capacity

You could see this as the storage capacity of the filter. It indicates the amount of accumulated contamination you need to replace the filter with. If you have a filter that filters a lot of contamination from the liquid or air to be filtered, this will of course remain in the filter. At a certain point, the filter has accumulated so much contamination that the filter loses its purifying effect or builds up so much blockage that the throughput decreases. The capacity indicates how long a filter can last and with what level of contamination.

Filter efficiency

This indicates how well a filter is able to retain contamination. This always depends on two factors. The first is what size particles the filter can retain. This is often referred to as micron. A micron is one-thousandth of a millimeter. So very small. If you want to put it in context, a human hair is about 50 microns thick and a red blood cell in our blood is about 6 microns. So if a filter can stop particles of 10 microns, then these particles are slightly larger than your red blood cells. The second thing that determines the efficiency of a filter is how many of these particles are retained. If a filter has an efficiency degree of 99.9%, you know that this is the percentage of particles, of the previously defined size, that are retained in the filter. It is interesting and actually very logical that a filter that is 99.99% efficient stops a hundred times as much pollution as a filter with an efficiency of 99%.

An absolute rating is often also indicated for a filter. This is the size of the particles that are 100% purified from the liquid or air. In other words, particles of this size and larger are completely filtered and nothing of this size passes the filter.

Filter throughput or flow

This indicates how well a filter can allow the oil or liquid to flow through the filter. It is of course fantastic if the purification is very good, but if you hardly have any throughput, then too low pressure is created on the other side of the filter. This would, for example, cause your engine to not get enough air or oil. You can imagine that this not only adversely affects performance, but can also cause major damage. In hydraulic filtration you have an additional problem if the throughput of your filter is not good and that is cavitation. This is the formation of small air bubbles that then implode in your hydraulic oil and therefore generate very high temperatures on site. These temperatures reach thousands of degrees and cause damage to your hydraulic motors, pumps and valves.

In addition, with some oil and hydraulic filter applications it is particularly important that there is a good flow from the very first moment. For example, when an engine is cold started, the engine oil is still viscous and does not pass through the filter media properly. Since you want your engine to receive oil directly as lubrication, you do not want it to be held back by the filter. This is where a bypass valve can make the difference.

Where do high quality filters make the difference?

If you know what basic properties a filter has, you can also look at the benefits of a higher quality filter. What is the reason for this better quality?

Flow design

The liquid or air has a certain flow in the filter. The quality manufacturers spend many millions every year on research and engineering. A large part of this goes to flow management in a filter. The shape of the filter, the openings, valves and everything that is in a filter determines the flow through the filter. In the optimal world, you want a filter to reduce the pressure of the liquid or air as little as possible. You only want to purify this, but not hinder the flow. Filter designs are often made with advanced CAD and other specialist software in which the flow in the filter can be precisely predicted. At almost all manufacturers, the ultimate test takes place in the laboratory. Here we not only test the efficiency of a filter, but also the throughput and how much pressure loss occurs.

Filter media

The filter media is the part in a filter that does the actual filtration. There are different types of filter media. For example, cellulose or paper, fiberglass or complex synthetic substances. Often it is the combination of different materials in one and the same filter that gives the unique properties and efficiency. In addition, the major brands produce many filters for unique applications and machines. You will not recognize these filters because they have the logo of the machine brand. Because these filters are made specifically for the application in that one machine, they also have specific properties.

What also makes a difference is that quality filters often use more filter material. For example, in an air filter, the amount of material used also indicates how much dust and contamination a filter can retain. If more filter media is used, the filtration surface of the filter is also larger and it can retain much more contamination. This significantly extends the life of the filter.

As an example, below is the calculation of the lifespan of an air filter. For this specific case we use the AF1905M filter from Fleetguard. This filter has a significantly larger filter surface because it has incorporated more filter material in the filter.

Fleetguard AF1905M

• Dimensions of a sheet = 400mm X 49mm
• Material weight = 250 grams
• Number of sheets = 293
• Total filter surface = 11.48 M²
• Maximum capacity = 2,871 kilograms

Filter from a competitor

• Dimensions of a sheet = 400mm X 49mm
• Material weight = 250 grams
• Number of sheets = 204
• Total filter surface = 7.99 M²
• Maximum capacity = 1.99 kilograms

Because more material is incorporated into the filter, the Fleetguard AF1905M filter has a much higher capacity before it is clogged, namely 2.9 kilograms versus 2 kilograms with the competitor. The Fleetguard filter in this example can therefore last 30% longer before it is completely clogged and needs to be replaced.

Quality tolerances

The major brands in filtration have a special focus on manufacturing tolerances. There are extensive quality controls and all these manufacturers are ISO certified. With an ISO certification, a lot of time is spent assessing the quality controls that the manufacturer has in place. This means that the filter always delivers the agreed performance, has a good fit for your application and that the tolerances in the product avoid filters can go straight in the bin because they simply don’t fit.

The benefits in practice

Below we describe the benefits in practice. After all, all that technical information is nice, but what does it yield in practice?

The filter fits just fine

If you are doing maintenance, there is nothing more irritating than a filter that does not fit. For example, because the thread of your oil filter is not so precise that it can be screwed onto the filter head. With lower quality filters, you may have one in four or five filters that do not fit. You can throw away this filter and your advantage is gone. It would be even worse if you also destroy the thread in your filter head due to the wrong thread in the example.

Filter lifespan

As described above, high quality filters have a much better capacity. This means your filters will last longer and you won't have to replace them as often. Manufacturers such as Fleetguard and Donaldson now also offer indicators that tell you exactly how long your filter can last. If you install these indicators on your machine, you can be sure that you are using the maximum lifespan of your filter and that you are not replacing your filter prematurely.

Longer lifespan of your machine

If you use higher-quality filters, you can be sure that almost all contamination is purified from the oil, liquid or air. This means your hydraulic system, engine or cooling will remain good for much longer. In practice you can say that good filtration gives your engine an approximately 17% longer lifespan. A minimal amount of dust or contamination in your engine can cause it to break down. For smaller engines, this is approximately 50 grams over the entire life of the engine. For large engines, for example trucks and larger construction machines, this is approximately 200 grams. This is extremely little if you know what air and fuel these machines get through the engine. As an example, a larger passenger car with a consumption of 11 liters per 100 kilometers requires 161,000 liters of air per 100 kilometers. This is only the air that is burned in the engine. If you know that your car's engine needs a complete engine overhaul with approximately 100 grams of dust in the combustion process, then you want to be sure that you use quality air filters to prevent this.

With hydraulics, it is mainly wear and tear that causes your pumps, valves, cylinders and motors to fail over time. Hydraulics often works with high pressures and very fine tolerances. They are precision parts that no longer function properly if the tolerances deteriorate. This will at the very least result in reduced performance and at worst you will end up with expensive repairs. 70% of repairs in the hydraulic system can ultimately be traced back to improper filtering of the hydraulic oil.

Lower overall costs

If you add the long-term benefits of quality filters, such as a longer lifespan of your machine, to the direct profit, such as a longer lifespan of your filter, you can quickly conclude that it is worth going for that slightly better filter. . It may seem tempting to choose the cheaper filter, but in the end you are guaranteed to pay more.

Want to learn more about some of the top brands in filtration? Then read our articles about Mann, Fil and Donaldson.

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