High efficiency low resistance filter (δp≤50pa)

Well, let's talk about filters? I don't like these pretentious statements about 'best technologies' and 'unprecedented results'. As a rule, everything is much simpler (and more complicated) in reality. And this is the topic -high efficiency low resistance filter, with pressure drops of up to 50 pascals - it constantly raises questions. Many people believe that 'low resistance' and 'high efficiency' are mutually exclusive concepts. My point of view is that it is not. The main thing is to find a balance. And then, understanding this balance requires experience, and not just theoretical calculations.

What is hidden behind the apparent simplicity?

It seems that everything is clear: you need a filter that traps dirt well, but does not greatly restrict the air flow. Sounds great, right? But if you dig deeper, a lot of nuances immediately emerge. Let's start with the most important thing - the definition of 'high efficiency'. What does it mean? Does the filter catch 99.9% of particles of a certain size? And what is the size of these particles? And what about particle sizes that are smaller than the minimum capture size? This is all critically important, and often underestimated.

I remember how in the early 2010s we tried to introduce filters declared by the manufacturer as 'ultra-highly efficient' into the air purification system at one of the large production sites. On paper, everything was just great - the stated characteristics met the requirements. But in reality... The resistance turned out to be too high, which led to a significant increase in fan power consumption. And, what is most unpleasant, the efficiency, according to real data obtained after several months of operation, was 5-7% lower than declared. We had to go through different options, and in the end we settled on a compromise solution. This is an important lesson I learned for myself.

The problem is that manufacturers often simplify the characteristics without specifying critical parameters, such as the distribution of resistance across different air flows, the effect of humidity and temperature on filter characteristics, as well as the life cycle and rate of filter contamination.

Filter Types and Their Tradeoffs

There are many types of filters, each with their own pros and cons. Bag filters are a time-tested option, but their resistance can be quite high, especially when dirty. Electric mesh filters are more effective at trapping small particles, but require regular cleaning and have a higher operating cost. Cyclone filters are effective for pre-cleaning air from large particles, but are not capable of capturing fine dust. Activated carbon filters have recently become popular, but their effectiveness depends on the type and quality of activated carbon, as well as the parameters of the gas environment.

Filter selection is always a compromise between efficiency, resistance, cost and operation. There is no universal solution suitable for all cases.

CompanyTianjin Tongchang Junqi cleaning equipmentworks closely with the Air Conditioning Research Institute of the China Institute of Building Sciences to develop and produce filter products, allowing us to offer optimal solutions tailored to specific applications.

Details that matter

Pay attention to the materials of the filter element. Some filters are made from polypropylene fabric, others from cellulose, and others from more complex composite materials. Each material has its own characteristics - resistance to chemicals, operating temperature, service life. And the choice of material must correspond to the operating conditions.

The constructive aspect is also important. For example, having a profiled filter housing can improve air flow distribution and reduce resistance. And having an automatic cleaning system can significantly reduce operating costs.

In our practice, situations often arise when a filter with a high rated efficiency turns out to be ineffective under real operating conditions due to the wrong choice of material or design. Sometimes even a minor detail can play a decisive role.

Real case: air purification in a woodworking shop

We recently worked on a project to purify the air in a woodworking shop. The task is to capture small particles of wood dust, which pose a health hazard to workers and can lead to fire. The customer initially selected a filter with a high rated efficiency. But after several months of use, it was discovered that the filter quickly becomes clogged with wood dust, which leads to a significant increase in resistance and a decrease in efficiency. It was necessary to replace the filter with a more durable and pollution-resistant one, and also introduce a system for periodic filter cleaning.

This case shows that it is not always worth relying only on the nominal characteristics of the filter. It is important to consider the actual operating conditions and select a filter that meets these conditions.

Taking into account the experience gained in developing filters, the companyTongchang Cleaningactively participates in the development of the national standard GB/T-13554 “High-efficiency air filters”.

How to choose the right filter?

So how do you choose the right filter? Where to start? First, the requirements for efficiency, resistance, cost and operation must be clearly defined. Secondly, it is necessary to take into account operating conditions - temperature, humidity, presence of chemicals, type and size of contaminants. Thirdly, you need to contact specialists who will help you choose the optimal solution.

Don't be afraid to ask questions, demand detailed information about the filter's characteristics, or ask for recommendations on operation and maintenance. And remember that choosing a filter is an investment in the health of your workers and the safety of your equipment.

If you have questions or need advice, please contact us. We are always happy to help!

Additional Considerations

Recently, there has been growing interest in filters with variable resistance. These filters allow you to maintain a constant air flow at varying levels of pollution. They can be useful in situations where it is necessary to reduce fan power consumption.

It is also worth paying attention to filters with an indication of the degree of contamination. This allows for timely cleaning or replacement of the filter, which prevents a decrease in efficiency and an increase in resistance.

Remember that regular filter maintenance is the key to their longevity and efficiency.