Types of HVAC UV Lights
There are two types of UV lights for HAVC systems.
- Coil Sterilization – A “stick type” light installed inside the return air duct near that sterilizes the air handler coil. A coil sterilization UV light runs 24/7 and is the most common type of HVAC UV light. It is also most reasonably priced
- Air Sterilization – A complete UV light unit that sterilizes moving air. The UV light unit is installed in the return air duct and cycles on with the air handler blower.
Studies Prove Effectiveness
Two studies point to the effectiveness of UV light in killing mold and bacteria, one in hospitals and the other in a commercial HVAC system.
- Ultraviolet Light Effective in Hospital Infection Control – In 2012, Researchers at Duke University Medical Center used ultraviolet radiation (UV-C) to nearly eliminate drug-resistant bacteria in 50 hospital rooms, reducing the number of bacteria by more than 97%.
- Effectiveness of Germicidal UV Radiation for Reducing Fungal Contamination within Air-Handling Units – In this commercial office building, and after 4 months of operation, “the fungal levels following UV operation were significantly lower than the levels in control AHUs (air handler units).”
Maintenance
The Second Wind UV stick light bulb is estimated to last 9000 hours, just over 1 year… Replace the bulb during each annual HVAC service and maintenance is nearly effortless.
Energy Cost
The Second Wind UV light we installed is rated at 1.1 amps. To calculate annual energy costs, I used these handy calculators
- Convert Amps to Watts – 24v AC at 1.1 Amps = 26.4 Watts
- Convert Watts to Electricity Cost – 26.4 Watts * 24 hours/day * 10.5 cents kWh = $24.28 per year ($2.00 per month)
For just under $500 per year, my family has peace-of-mind knowing that we are breathing the highest-quality indoor air. It seems like a small price to pay. But it doesn’t make sense to install an HVAC UV light unless you’ve followed the indoor air quality priorities.
Indoor Air Quality Priorities
While HVAC UV lights are effective for killing mold, bacteria, germs and odors, make sure you have completed the indoor air quality basics:
- Seal air ducts during renovation or construction
- Install ducts in conditioned space
- Ensure air-tight ducts, sealing all joints with mastic.
- Install high-MERV filters, but be sure your HVAC system is designed for the higher static pressure of better filtration
- Install UV light in HVAC system
- IMPORTANTLY: Conduct regular scheduled maintenance with your HVAC company, changing filters monthly and cleaning the coil annually
Benefits
HVAC UV lights:
- Control mold and bacteria
- Reduce colds and flus – as so, germs are not re-circulated by HVAC system
- Reduce smells / odors
- Remove VOCs
- Are more effective in humid climates than dry climates
- Reduces clogging in condensate drain lines by preventing algae growth.
- Maintain a cleaner coil, improving cooling efficiency and reducing electricity costs.
Disadvantages
HVAC UV Lights:
- Don’t clean flowing air unless air sterilization UV lights are installed
- Destroy non-UV stabilized plastics in the air handler. Only items in the line of sight are affected
Manufacturers
- Second Wind (coil sterilization)
- Guardian Air / REME (coil sterilization)
- Fresh-Aire (Triatomic Environmental) (coil sterilization)
- Honeywell – (coil sterilization) Be sure to pick the new model lamps
- Lennox Healthy Climate UVC Germicidal Lights (coil sterilization)
- Carrier Performance Series Germicidal UV Lamps (coil sterilization)
- Trane –Trane’s Position on UV-C Lights
Bottom Line
HVAC UV lights are an effective means for improving indoor air quality, but only after following the indoor air quality priorities. Install an HVAC UV light and experience healthier indoor air quality.