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Patented new filtration technology proved it can upgrade AC units and Air Curtains to become highly effective Air Purifiers.

Background and problem

AC Split Units and Air Curtains employ coarse dust filters that are normally installed within the housing at the air return vent to allow for frequent filter cleaning. While this vital activity is generally performed on a regular basis in professional settings, it may be overlooked in home settings, leading to the clogging of these filters. This decreases device efficiency and, in general, leads to increased energy consumption. As a result, frequent preventative filter maintenance is advised as an industry standard.

As a result, frequent preventative filter maintenance is advised as an industry standard

While the existing filters are adequate for keeping the machine coil clear of coarse particles, they are all based on the ‘sieve’ filtering concept. As a result, they are unable to gather fine PM10, PM2.5, and ultra-fine PM1 particles, which are crucial for maintaining healthy in-room air quality. These invisible dust forms are simply circulated around the room.

Airflow resistance problem

In cooling mode, the given humidity condenses, and when combined with passing fine dust, this can lead to the production of biological hazards such as mold and bacteria within the coils, making dirty AC units a source of deteriorating air quality over time.

Professional servicing is usually necessary to clean the coils, which adds another cost factor to consider. Using a standard HEPA filter would be impossible since its resistance would diminish the airflow rate, rendering the AC or Air Curtain inoperable.

Generating air turbulence

The double-layer filter is built with parallel and staggered filter rods to generate air Turbulence

How to solve the airflow resistance problem - Dexwet Filters, a global technology company based in the United States, created a novel and radically different filtration approach that allows for minimal airflow reduction while successfully capturing PM10 particles down to PM1.

The double-layer filter is built with parallel and staggered filter rods to generate air Turbulence while allowing for easy air passage with minimum resistance, akin to the human nose. The filter rods are covered with a sticky medical-grade silicone fluid that, like fly paper, permanently traps particles of any size and absorbs them into the oil. When the filters need to be serviced, there is no need to discard them because they can be easily cleaned with simple washing.

The double-layer filter is built with parallel and staggered filter rods to generate air Turbulence
The double-layer filter is built with parallel and staggered filter rods to generate air Turbulence

Internal coarse dust filter

How low airflow resistance filters work to protect both machine and human health - Recent case studies with retrofitting Dexwet Filters to existing AC units show that the physical concepts of ‘Turbulence and Absorption’ were implemented with a minimal airflow decrease of less than 7%. 

Studies also proved that the resistance required no additional energy and that the AC unit operated normally. Because the filters were installed onto the intake vent as a prefilter to the existing internal coarse dust filter, they offered extra filtering, allowing the internal filter to operate for extended periods of time before needing to be cleaned.

Improved energy efficiency

More importantly, it not only kept the existing filter cleaner for a longer period of time

More importantly, it not only kept the existing filter cleaner for a longer period of time, but it also protected the coils from high ratios of PM10, PM2.5, and PM1 particles, reducing the formation of bio-hazards such as mold and bacteria, combining Dexwet labels as machine health with improved energy efficiency.

In terms of human health protection, it was demonstrated in the aforementioned case study and in relation to the effect on indoor air quality that up to 60% of PM2.5 concentration within the room could be lowered during one ACR (Air Change Rate), which took only 15 minutes. The combined results of filter effectiveness and energy consumption outperformed the best conventional Air Purifiers based on HEPA filter technology, which became a thriving new market segment as people became more aware of the fine dust problem, air quality in general, and the recent pandemic in particular.

It's all about ACR (Air Change Rates)

Adding these filters to an existing Split Unit AC with an ACR of 4x essentially transforms the AC into an air purifier. According to the principle stated above, the higher the ACR, the greater the number of filter passes, resulting in greater air clean air efficacy. Because ACR is directly related to the effectiveness of cleaning the air, as ACR rises, so does air quality.

Air Curtains have a significantly greater ACR than the AC units mentioned above

Air Curtains have a significantly greater ACR than the AC units mentioned above. AC units normally work at roughly 3mph, resulting in an ACR of 4x per hour, whereas Air Curtains function at around 21mph, which is 7x faster than AC units. It is tentatively predicted that an Air Curtain can enhance continuous interior air quality by a factor of 5 when compared to a single AC unit.

Air Curtain Effectiveness

Because Dexwet is always pushing the boundaries of its technological capabilities, outstanding results were achieved in a recent refit application in a money counting room. Money may not stink, as the ancient Romans understood, but money counting is a dirty operation.

The continual rotation of banknotes in money-counting devices creates extraordinarily high dust emissions into the air. As a result of the employees' respiratory issues, the supplied Air Curtain was modified with a retrofitted Dexwet Filter on the front outside as a retrofit remedy. After only three weeks, the filter already appears quite dirty from the front but has not yet collected enough debris on the second layer to necessitate filter repair.

Maintenance cost savings

Prior to installation, the Air Curtain unit needed to be cleaned once a month

Prior to installation, the Air Curtain unit needed to be cleaned once a month; currently, it only has to be cleaned once a year, with the filter changed every 60 days, resulting in significant maintenance cost savings.

Dexwet filters for Split AC and Air Curtain Units are now only available through service partners globally. The ideal long-term answer would be for their filters to be included in an AC or Air Curtain manufacturer's OEM machine design. This would provide them a competitive edge by allowing them to be the first to offer Air Purification as an add-on feature to their existing products.

Prior to installation, the Air Curtain unit needed to be cleaned once a month
Prior to installation, the Air Curtain unit needed to be cleaned once a month

Expanding usage opportunities

Clemens Sparowitz is Chief Operating Officer (COO) at Dexwet Holdings Corporation. He has more than two decades of experience as a successful entrepreneur, executive, developer, and published author.

He oversees the operational tasks related to managing Dexwet’s manufacturing and assembly partners. Since joining the company, Clemens has led multiple groundbreaking projects, including the successful application of Dexwet’s innovative technology to NASCAR-Europe and the development of the two most recent generations of air filter technology expanding usage opportunities beyond machine health to human health including via HVAC systems.

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Author profile

Clemens Sparowitz President and Chief Operting Officer, Dexwet Holdings Corp.

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