Adding ultraviolet (UV) lights to your HVAC system can help to kill mold, viruses and bacteria and keep your home’s air clean and fresh. Continuously exposing your evaporator coil or the inner surfaces of your ductwork to UV rays can prevent pathogens from multiplying and boost energy efficiency. Below, we’ll discuss how to integrate UV lamps into your HVAC system, and why proper placement is key to safely improving your air quality.
What Is Ultraviolet Light, and How Does It Purify the Air?
UV light, and ultraviolet C (UVC) light, particularly, is a type of invisible electromagnetic radiation that is emitted from specially designed mercury vapor lamps. When this light shines on microorganisms, it destroys their DNA or RNA and prevents them from growing and reproducing.
Fitting your HVAC system with germicidal UV fixtures will help to prevent bacteria, viruses and mold from accumulating within your HVAC system, becoming airborne and circulating throughout your home. As a result, you’ll breathe in healthier air, free from biological contaminants, and lower your risk of experiencing respiratory ailments.
Installing a UV light in your HVAC system can benefit you by:
- Reducing airborne allergens
- Enhancing your HVAC system’s energy efficiency
- Eliminating unpleasant odors
- Keeping your system cleaner
How UV Light Fits Into Your HVAC System
To enjoy the advantages of UV-light sanitized air, proper selection and installation is key. Most UV lights for residential air purification are low-pressure mercury-vapor lamps that produce 253.7 nanometers (nm) of shortwave UVC light, which serves as an effective general-purpose disinfectant. Unfortunately, exposure to UVC light can also damage human cells, so the lamps must be shielded to prevent the rays from escaping into the open air.
UV lights are manufactured as coil-sanitizing lights and air-sanitizing lights that fit into different parts of your HVAC unit. Technicians can hardwire these energy-efficient fixtures to your HVAC system’s power supply to shine when the system is running, or they can be plugged into an outlet.
Coil-Sanitizing UV Lights
Coil-sanitizing lights are typically configured as an array of long, thin tubes that are suspended above, in front of or beside the evaporator coil of your HVAC unit. They are positioned so that their light shines directly onto the evaporator coils and targets microorganisms on the metal. Since the evaporator coils contain the HVAC system’s refrigerant, their surface and surrounding air tends to be cool and moist.
These conditions create a hospitable environment for mold, bacteria and biofilms to flourish, especially in humid climates. A UV light placed within your HVAC system is most effective when the humidity levels are below 60% and your home is well-ventilated. Using a high-quality air filter in conjunction with UV light is the best way to improve your indoor air quality.
The exact placement of your UV light depends on whether your evaporator coils are A-shaped or N-shaped.
If your evaporator coil is A-shaped, your technician should center the UV light directly above and downstream of the coil so that it shines on every surface of the coil, as well as your system’s drain pan.
If your HVAC unit’s evaporator coil is N-shaped, your technician can install the UV light above the coil so that its light shines on the coil’s fins and the system’s drip pan. Sometimes, technicians can install the light within the N shape or add a second UV lamp to ensure that the light will reach all the coil surfaces.
Air-Sanitizing UV Lights
Air-sanitizing UV lights fit inside your HVAC ductwork and function as whole-house air purifiers. Your technician will install these lights in the supply or return air duct, near the evaporator coil or air handler. This placement ensures that the UV light sanitizes the air, as it flows through the ductwork, by killing any pathogens that are already airborne.
Maximizing light exposure on moist surfaces within your HVAC system is the best way to stop microbial growth, but there is a caveat: In most cases, the technician must also prevent the light from shining on your system’s air filter. The UV light will break down the materials in standard air filters and damage them over time.
Alternatively, your technician may be able to install an electrostatic media, or UV-resistant, air filter in your HVAC system. Finally, the UV lamp must be covered so that its rays cannot escape into the open air where they could shine on people or pets. Hiring a trained HVAC professional will ensure that your UV light will safely and effectively sanitize your home’s interior air.
Finding the best placement for a UV light depends on whether you have a central, ductless or window-mounted HVAC system. A professional HVAC technician can find the ideal location for your UV lamp.
Are HVAC UV Lamps Safe?
HVAC UV lights are safe for your family and pets when they are installed properly and used correctly. When UV lamps are fully enclosed within your ductwork or HVAC unit, the light will reach only the system’s interior surfaces. If the UV lamp is properly shielded within the ductwork or the HVAC system’s enclosure, you will not have to worry about being exposed to UVC radiation, which can be harmful to skin and eyes, cause cellular damage and potentially increase the risk of cancer. UVC radiation can cause skin burns, cataracts, macular degeneration and other injuries and disorders, so it’s vital to ensure that it is sealed from your living environment.
Another concern with some HVAC UV lamps is that they may produce ozone when they interact with oxygen in the air. Ozone is a known health hazard that can irritate your lungs. High-quality HVAC UVC systems are designed to block the radiation that produces ozone, so be sure to account for this fact when you’re working with a technician to choose an HVAC UV lamp.
Remember that proper installation is the key to ensuring your HVAC UV light is working safely. An expert HVAC technician will be able to position the light correctly to ensure that no UVC radiation leaks into your living areas. They can also install a safety switch that will shut off the light automatically if an access panel comes loose or is opened accidentally. Finally, scheduling regular maintenance and replacing your UV lamp every 12 to 24 months can improve its performance and safety.
A Well-Positioned UV Light Can Safely Improve Your Air Quality
If you want to breathe the cleanest air possible, adding a UV light to your HVAC system is an effective way to reduce your exposure to unhealthy microbes. The pros at Landon Heating and Cooling in Zebulon, NC, are trained to recommend the best ultraviolet lights for your system and install them properly so you can safely disinfect your home’s interior air.
UV light can help guard against mold, bacteria and viruses and keep your household healthy. To schedule a consultation with our specialists, call our office today.
