UV Lamps are one of the most significant of the modern air purification technologies. Medics and other professionals have used this process for many years to disinfect surfaces and water. The technology doesn’t replace the HEPA filtration system. Rather, it complements HEPA filters, and the combination offers a system that cleans the air better.
UV light doesn’t have any effect on dust and other particulates, and this is where the HEPA filter comes in to trap those substances. That much is obvious, but how do UV lights work?
The Use of UV Light in Air Purifiers
UV light air purifiers use short wave light to destroy the DNA of microorganisms. The light can inactivate bacteria, mold, and viruses, among other organisms. Also known as germicidal irradiation or UVGI, the technology is meant to reduce indoor pollutants so that you can breathe better and stay healthy in your home.
You can install one of these in your central AC unit or use it as a stand-alone system. When used as a stand-alone unit, the system has its own HEPA filter to further enhance the quality of the air you breathe. It works by sucking air into the UV-C chamber. While inside the chamber, the light tries to inactivate the microorganisms in the air.
Other devices, however, install into your central HVAC system. These are not effective as stand-alone units. As noted earlier, UV doesn’t purify particulates such as dust in the air or remove them. You need a HEPA filter to make the air purification complete.
At Reliable Air Conditioning, we can help integrate either of these devices with your present HVAC system to ensure you enjoy cleaner air in your Gilbert home at all times.
How Does the UV Lamp Work?
Germicidal UV is responsible for inactivating various microorganisms. This light has been in use since 1908, when French municipalities used it to treat water. Since then, the technology has been taken up by hospitals, laboratories, and food processing plants and used to disinfect surfaces.
Most ultraviolet lamps produce UV light from quartz and mercury. The lamp sports a quartz tube body. Within the tube, mercury is used to facilitate the production of UV light.
When you switch on the light, the voltage at the electrodes ionizes the gas inside the lamp. In most cases, this gas is xenon. The voltage also raises the temperature inside the tube to between 1550 degrees and 1750 degrees Fahrenheit and excites the mercury within its confines. This mercury creates a plasma arc that produces UV light. According to the EPA, most lamps emit UV-C light with a wavelength of about 230 nanometers.
However, depending on the brand, some lamps emit less potent UV-A and UV-B light. These lamps are still effective, but they need more contact time with the bacteria to destroy its DNA.
Mercury lamps are the most effective, but they require more energy to run. When you switch on the light, you need to allow the chamber to heat up to 1550 degrees Fahrenheit to emit UV-C. After being switched on, they need time to cool down. The warming and cooling periods make the lamps power-intensive.
You can choose a pulsed xenon gas lamp that offers a more energy-efficient operation. One of these lamps gives off longer wavelength light and produces safe xenon gas during operation. However, it will also need more contact time with the microbes to inactivate them. There is a challenge with this type of device because it is dedicated hardware and requires advanced skills to install.
To make UV lamps more efficient, engineers designed LED UV lamps. These do not consume as much energy as the other lamps, but they are less potent. One of these eco-friendly and durable lamps works best when you need to disinfect delicate surfaces. However, because they are less potent, they take longer to inactivate the microbes in your indoor air.
Which Form of UV Light Is Normally Used?
UV light is divided into three categories. Most UV lamps use UV-C, which is the most potent form of UV light.
The first category is UV-A, which has a wavelength of between 315 and 400 nanometers. Its photons vibrate faster than those of visible light.
UV-B is the second category of UV light, and it has a wavelength of between 280 and 315 nanometers. Its photons vibrate even faster than those of UV-A. Although UV-A can also damage the skin and cause premature aging of the tissue, UV-B is the biggest culprit. When you think of sunburn and skin cancer, you’re envisioning the damage caused by UV-B.
UV-C, which is used in UV lamps, is the third category. Its photons vibrate the fastest, and it has a short wavelength of between 100 and 280 nanometers. Thanks to the fast vibration, this light has the most energy. Although this variety could potentially damage the skin, and you don’t want to look directly into it, the mechanism that produces it for home use is shielded. Let a professional install it, and don’t tamper with it afterward.
When the system draws air from your home, molecules inside organisms absorb the energy from UV-C. Because the energy is too much, it damages the molecules. In this case, these molecules are DNA molecules in the microorganisms contaminating your system. Once their DNA is damaged, these one-celled organisms will not survive.
The process of producing the light also doesn’t involve any noise. Most of the systems, stand-alone or incorporated, are installed after the HEPA filtration system. So, the forced air system passes air through the HEPA filtration system first and then into the UV-C chamber. The filter traps particulates such as dust while the bulbs emit UV-C, which inactivates microbes. When these two systems work in coordination, they purify the air in your home.
It takes the UV lamp about 60 minutes to purify the air in a room. However, to continuously clean the air, you might want to leave it on as long as the air conditioning system operates.
Are UV Lamps Safe?
Yes. These lamps have a coating that ensures you are never exposed to UV light at all. What most people fear from these lamps is the danger of being exposed to ozone.
When exposed to the free air in your indoor space, the UV-C light splits the free oxygen (O2) into two atoms. These atoms can then react with the free nitrogen in the air to form ozone (O3). Exposure to ozone for a short time is not dangerous to your health. However, if you are exposed to ozone for a long time, you might end up having breathing difficulties. Manufacturers of UV lamps ensure that doesn’t happen by coating the lamps appropriately.
Instead, these lamps make the air in your home safer for you to breathe. They are effective in removing bacteria and viruses. They can also inactivate mold spores, but studies show that mold can still cause allergic reactions even when inactivated. To make the system effective against particulates such as dust and allergens, manufacturers fit them with HEPA filters.
The effectiveness of UV lamp air purifiers is determined by:
- The duration of exposure of the microorganisms to the light
- Whether the cooling effects of the AC affect the working of the lamp
- The emitters the manufacturer uses in the light
- The population of microorganisms in the air in your home versus the dosage of light emitted
- The humidity and temperature of the room
Certified Technicians at Your Disposal
At Reliable Air Conditioning, we offer heating and cooling services, including installation, repair, and maintenance of your HVAC system and indoor air quality equipment. You can call us for home energy audits, ductless mini-splits, radiant heating, whole-house fans, boilers, air balancing, and refrigeration, among other things. We serve Gilbert and the surrounding areas. Call Reliable Air Conditioning today to discuss any of these options with an expert. We’d be happy to give you a free estimate.
