Frequently Asked Questions

1

What about other products being advertised as providing improved Indoor Air Quality?

Here are some examples we have seen or heard advertised over the years and a little background about each of them: Activated Oxygen is ozone. The Federal Drug Administration (FDA) has determined that ozone, to be effective as a bactericide or deodorizer, must be present in greater amounts than can be safely tolerated by people or animals.

Photo-Catalytic Oxidation (PCO) is a proven technology, but a large amount of catalyst is necessary to be effective at 50% oxidation.

Cold Plasma System produces "singlet oxygen." This is a single, unstable molecule that seeks to attach itself to another element.

Ion Generators use a proven technology but are typically used in a room air purifier, which only treats the air in one area. More importantly, they do not impact microbial growth in the dark, damp environment of the air conditioning system. When applied in HVAC systems, this technology attracts small particles to each other, creating larger particles that fall out of the air stream.

Note: None of these technologies are acknowledged by ASHRAE, unlike
Germicidal Ultraviolet Light (ASHRAE Standard 180), which is SPECIFIED by
ASHRAE.

2

Why aren't air filters enough to maintain good indoor air quality?

Air filters, including High Efficiency Particulate Air (HEPA) filters, have been used for many years in heating, ventilating, and air conditioning (HVAC) systems. Some are very effective in trapping particles like pollen and dust. Unfortunately, most do not trap very small particles like viruses, bacteria, and mold that grow in the dark, moist environments of HVAC systems downstream of filters.

Regardless of the type of filter used, it is critical that all filters be sealed around the edges to prevent the bypass of particles.

There is also a problem with fungal spores growing and multiplying in damp HEPA filter material. When this happens, the filter can actually grow mold and spread throughout the energy of the building.

Ultraviolet germicidal devices radiate powerful UVC energy onto the coils and drain pans inside the air-conditioning system, where mold and other odor and disease-causing organisms grow. The UVC light inactivates and gradually vaporizes this microbial growth, thus accomplishing what the air filter cannot do.

3

What other methods (beside UVC) are used for cleaning inside air handling units?

Coils are cleaned with various combinations of detergents, solvents, biocides, foaming cleaners, and high-pressure hot-water sprayers. When cleaning is neglected, the build-up of mold inside the coils becomes very difficult to remove.

Chemical cleaning of HVAC equipment is time-consuming. It must be done properly to be effective, and it must be done regularly since contamination returns as the chemicals wear off. The toxic chemicals present health issues for the workers doing the cleaning, as well as for building occupants. And some chemicals cause corrosion to the metallic surfaces, shortening the life of the equipment. As we all now know, chemicals going down the drain is not advisable or sustainable.

Pressure washing of the coils may force mold and particulate deeper inside, further restricting the air flow. When this happens, it becomes virtually impossible to physically clean the coil.

UVC lights, by contrast, effectively inactivate mold and other microbes. As the organism remains are washed down the drain pan by the condensate, UVC rays penetrate deeper into the coil until all particles and volatile organic compounds (VOCs) have been washed out.

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4

How can I tell that indoor air is contaminated?

Sniff the air. The nose is the best odor and gas detector, and a good particle detector as well, especially when first entering a contaminated environment. Unfortunately, in as little as 15 minutes, it adapts to the environment and stops detecting contaminants.

Chronic respiratory distress, headaches, and fatigue may also be signs of contaminated air.

5

What causes the musty smell in air handling systems?

The cause is the growth of mold and bacteria in the drain pan and on the coils. The smell comes from the rich brew of microorganisms that breed on the cooling coil and in the drain pan water. The slow warming of this contaminated water releases a plethora of spores and toxins -- and the nasty smell -- into the air.

6

What is ultraviolet light?

Ultraviolet light represents a portion of the sun's electromagnetic spectrum. It is the wavelength band immediately below, which is the shortest wavelength of light visible to the eye. The UV range of the spectrum is characterized by wavelengths between 100 and 400 nanometers (nm). It includes the long-wave UV-A (315 to 400 nm), also known as black light, medium-wave UV-B (280 to 315 nm) used in tanning booths, short-wave UV-C (200 to 280 nm), and vacuum UV (VUV) (100 to 200nm). This (VUV) wavelength also produces ozone.

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7

What is UVC?

Short-wave ultraviolet radiation, in the "C" band of 200 to 280 nanometers, has been used in a wide range of germicidal applications since the late 1800s to destroy bacteria, mold, yeast, and viruses. UV-C, or UVC, is often referred to as germicidal UV.

8

What is UVGI?

Another commonly used acronym, UVGI, also refers to ultraviolet germicidal irradiation, which is the same as UVC.

9

Where should the lights be installed?

IAQ Energy Solutions offers a wide variety of UVC devices that can be adapted for virtually any system or application. In general, though, lamps are installed on the discharge side of the cooling coil and mounted to expose both the coil surface and the drain pan to as much light as possible.

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10

How much UVC light is enough?

The most important consideration is that UVC be installed so that there is a "line of sight" between the UVC lamp and the entire coil surface. The amount of germicidal UV necessary depends on the application. A working UM (Unit of Measurement) has been established to aid in the proper sizing of UVC needed to inactivate various microbes “on the fly” as they pass through the cooling coil and into the air handling system.

11

How often do the UVC lamps need to be changed?

The germicidal output of a UVC light is reduced by around 15% over 8-9,000 hours. UV output is measured with a radiometer. Typically the light is changed annually -- ideally in spring or early summer to provide optimal output during the peak air-conditioning season.

12

How much energy does a UVC device use?

UV lights consume very little energy. Normally, the cost per air handler is well under a dollar per day.

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13

Is ozone an air purifier or a contaminant?

Ozone is being marketed by some as an air purifier, often in conjunction with UVC.

It is true that UVC will produce ozone at low frequencies. The UVC devices that IAQ - Energy Solutions handles attenuate all frequencies below 200 nanometers so that no ozone is produced.

According to the U.S. Food and Drug Administration: "Ozone, to be effective as a bactericide or deodorizer, must be present in concentrations far greater than that which can be safely tolerated by man or other animals."

According to the U.S. Environmental Protection Agency, ozone is a toxic gas with vastly different chemical and toxicological properties than oxygen. When inhaled it can damage the lungs, and relatively low amounts can cause chest pain, coughing, shortness of breath, and throat irritation.

Ozone has been used effectively for years to clean waste water. In water containing organic material, ozone is used up rapidly -- before it reaches the air.

14

Is there any research on the effect of UVC on eliminating or preventing infectious diseases?

Yes, there is quite a bit of data on this. Upper Air disinfection has been proven to
be effective in controlling Tuberculosis since the 1950s and has emerged again
as a control for bio-aerosols like COVID-19 and the flu. Computer modeling developed by Dr. Vladislaw Kowalski in the early 2000s enables designers to specify enough UVC energy to inactivate up to 99% of most microbes, even in the cold, moving air environment of an air handler. Further research with computer modelling during the COVID-19 pandemic determined that UVC, along with a MERV 8 air filter, achieved the same COVID removal rate as the specified MERV
13 filter at a lower cost and lower pressure drop.

15

What if there are no unpleasant odors?

Even if there are no detectable odors, there is still microbial growth present. This is why ALL HVAC professionals know to clean coils and drain pans with chemicals once or twice every year to maintain HVAC system efficiency.

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