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How Photocatalytic Oxidation Helps to Improve Indoor Air Quality

For a long time, HEPA filters reigned as the gold standard in air purification technology. Their reputation is well-earned. However, they have drawbacks that prevent them from being a complete air quality solution. That is where air purifiers come into play. Today, the latest air purification systems use photocatalytic oxidation to clean your air. Here is everything you need to know about the technology and how it can help keep your home’s air healthy.

The Limitations of HEPA Filtration

HEPA filters do not kill microorganisms like viruses and bacteria; they merely trap them. As a result, if you fail to replace a HEPA filter on time, you risk allowing microorganisms to continue circulating. Many whole-house HEPA filtration systems need filter replacements annually. Some need new filters more often than that. And if you are not careful when handling a used filter, you can reintroduce contaminants into your air. HEPA filtration systems and their filters can be costly. As a result, you will find them most often in sensitive environments, such as hospitals. But they are more of an option of last resort in residential settings.

What Is Photocatalytic Oxidation?

Although it sounds complex, photocatalytic oxidation is a straightforward process. It relies on ultraviolet radiation and a catalyst to convert organic, carbon-based pollutants into harmless substances. Common byproducts include water and carbon dioxide. NASA has used the process to purify air and water since the 1970s. Today, the technology is increasingly appearing in residential air purifiers.

How Does Photocatalytic Oxidation Purify Air?

Photocatalytic oxidation-based air purifiers generally consist of a UV light source and a filter coated with titanium dioxide. The UV light emits radiation in the UV-C spectrum while activated. It is in the same spectral range as the most powerful radiation emitted by the sun. Fortunately, Earth’s atmosphere prevents any UV-C radiation from reaching the ground. If it did not, our planet would be uninhabitable. It is important to note that UV-C, while powerful, cannot penetrate solid materials, such as metal. So, it is perfectly safe for use inside a sealed air purifier.

When the UV radiation emitted by the light strikes the filter, the titanium dioxide absorbs its energy. The energy converts some of the titanium dioxide into hydroxide ions and superoxide ions. Both are short-lived and extremely volatile radicals. As a result, they attack carbon-based molecules in the surrounding air, breaking them down.

What Substances Can Photocatalytic Oxidation Destroy?

The process of photocatalytic oxidation can eliminate any organic material circulating in your home’s air. That includes things like viruses and bacteria. It also includes allergens and volatile organic compounds (VOCs), which are common contaminants in the air of an average home. They can come from such substances as household cleaners, adhesives, pesticides and air fresheners. They can cause various ill health effects ranging from headaches to sleep disturbances and organ damage.

The Benefits of Photocatalytic Oxidation

An air purification system that relies on photocatalytic oxidation can deliver significant benefits. Here are seven of them.

Healthier Indoor Air

Air purifiers that employ photocatalytic oxidation destroy harmful substances in the air instead of capturing them. That means you need not worry about recontamination from mishandled filters.

No Harmful Byproducts

Some air purification technologies can introduce harmful substances into your home’s air. Ionic air cleaners, for instance, can increase ozone levels in your home, which is very unhealthy. Photocatalytic oxidation produces harmless byproducts, such as water and carbon dioxide. As long as your home has adequate ventilation, neither can harm you or your home.

Inexpensive Operation

Most whole-home air purifiers that use photocatalytic oxidation have no moving parts. They rely on your HVAC system, which already circulates air while running. The only electricity the purifier uses is to power its UV bulb. In most systems, that equates to between 15 and 30 watts.

Silent Operation

Their lack of moving parts also means air purifiers using photocatalytic oxidation run silently. That contrasts with standalone air filtration and purification systems. Those often have their own built-in fans, which contribute noise to your indoor environment.

Excellent Odor Control

You may not know it, but many persistent odors in homes result from VOCs. Others are due to mold or mildew. In some cases, your HVAC system may harbor odor-causing substances and spread them around your home. An air purifier that uses photocatalytic oxidation can reduce those odors. It leaves your air smelling fresher and reduces the need for air freshener use.

Helpful for Allergy Sufferers

HEPA filtration has long been a go-to solution for people suffering from allergies. However, air purifiers that use photocatalytic oxidation are also very effective at controlling allergens. Their ability to destroy dander, mold and mildew can offer significant relief to allergy sufferers.

Minimal Maintenance Needs

Unlike air filters, air purifiers with UV lights do not accumulate dust and dirt. There is also no filter media to replace. The titanium dioxide-coated filter does not degrade quickly and can last for years in an air purifier. The UV bulb in the average air purifier needs replacement annually for best results. That is a task for an HVAC technician.

Integrating a Photocatalytic Oxidation System Into Your HVAC

Most photocatalytic oxidation air purifiers offer multiple installation options. In general, installation into your home’s return air ductwork is preferable. One reason is that it allows the system to treat the air before it reaches your HVAC indoor unit. That extends the system’s benefits to your HVAC, reducing contaminants can extend your HVAC system’s lifespan. To that end, many homeowners pair theirs with an extended media filter. That offers maximum reduction of both biological contaminants and airborne dust and dirt.

If installation on your HVAC system’s return side is impractical, supply-side installation is acceptable. In that case, you need to locate the device as far from any vulnerable parts of your HVAC system as possible. UV radiation can damage plastics, potentially harming your HVAC system over time.

In either installation scenario, the air purifier remains completely inside your HVAC ductwork. That helps contain the UV radiation and prevent any chance of accidental exposure. For that reason, it is important to know that photocatalytic oxidation systems are not user serviceable. Once you have one installed, leave all maintenance and repair to a qualified HVAC technician.

Your Local Indoor Air Quality Specialists

If you’re interested in adding a photocatalytic oxidation air purifier to your HVAC system, Hoff Heating & AC can help. We offer comprehensive indoor air quality solutions throughout O’Fallon, MO. We sell and install germicidal lights, air filters, ventilators, humidifiers and dehumidifiers. Our air quality experts can help you choose the perfect combination of solutions for your home’s air quality challenges. Since we offer support for the full lifespan of the products we sell, you can count on us to keep your air quality systems in top shape as long as you have them.

When you’re ready to improve your O’Fallon home’s indoor air quality, contact Hoff Heating & AC!