High powered 254 nm UV-C ultraviolet light germicidal solutions are regularly used every day in commercial and hospital implementations. With the coronavirus on everyone’s mind, now may be an optimal time to bring this technology into your home.
Scientists have known about the deactivation ability of UV lights, specifically germicidal UV lights (UVC) for decades. The good news is that by applying existing commercial technology to residential HVAC systems, single pass air deactivation of virus, mold and bacteria is not only possible, but available today.
To be effective, each system must be specifically configured to the duct system to be disinfected. Duct sizing, air flow speeds, deactivation zones, and the specific output of the multiple UV-C lamps to be used must be taken into account for each home. Some lamps, with an extra layer of insulating glass can operate at higher output levels in duct systems, and are sometimes the most cost-effective solution.
Ultraviolet purification systems utilize germicidal lamps that are designed and calculated to produce a certain dosage of ultraviolet (usually at least 16,000 microwatt seconds per square centimeter but many units actually have a much higher dosage.) The principle of design is based on a product of time and intensity – you must have a certain amount of both for a successful design.
Some systems, in addition to direct air stream, single pass UVC deactivation utilize UVC activated PCO (Photo Catylitic Oxydation) and activated carbon receptor banks to enhance the germicidal effect and also to remove odors and various volatile organic compounds that can potentially present health risks.
Also, in addition to direct air stream sanitization, coil sanitizing lights are often installed near each air conditioning coil to prevent the growth of mold and bacteria in the moist environment of the coil during the air conditioning season.
The typical installed cost for a complete system depends on the ductwork size and configuration but are usually in the range of $900 – $1600 per ton. Lower cost, but significantly less powerful systems are also available.
NOTE: Deactivating virus particles in a single pass requires considerably more UVC output than is available in typical residential UV light products. Effective but safe and reliable configuration design depends on the size and layout of your duct system.