UVGI Coil Irradiation using UV lights has been around since 1996, and has been gaining popularity due to the staggering energy savings and reduced installation costs. With new technology, fixtures, and more installations the inital, installation, and operation costs of coil irradiaiton systems has gone down so much that even HVAC units in Minnesota and Wisconsin have paybacks of typically 6-12 months. That is just in the energy savings alone, when you factor in additioanal "soft costs" such as diverted labor savings and the costs of other coil cleaning methods the payback is even faster. Here are a few examples:
First, let's answer the question of how much build-up on a coil it takes to significantly impact the energy efficiency of the coil. This is represented in heat transfer (or BTUH production) and static pressure loss across the coil. This chart shows what only 6/1,000ths of an inch does to the efficiency of a coil:
Clearly it doesn't take much to seriously impact how efficient a coil is at transfering heat. This expample shows that 6/1000" not only increases the coil temperature by over 7%, but the air also moves 18% faster through the coil. These combined inefficiencies lead to the HVAC system needing to work much harder and use significantly more energy to do the same amount of work.
For a 5 year old Roof Top Unit
The BTUH output is increased by nearly 10% after coil irradiation with UVC light. This equates into a $1,000 annual energy savings for unit that runs only 3,000 hours with a delivered electrical cost of 11cents per kWh, which for commercial buildings that typically use RTUs is a little below the national average. With an installed cost averaging $500 that gives a first-year payback of $500 per RTU!
40,000 CFM Air Handler
For a larger AHU that handles 40,000 cfm the numbers are just as impressive, with a BTUH capacity increase of over 12.5% and $8,403 annual energy savings if it runs only 4,300 hours a year and a lower deliviered electrical cost of 8cents per kWh. This coil irradiation installation, parts, and operating costs the first year are only $4,956 which results in a first year payback of over $3,400 - just in energy savings!
UV light has been established as an easy way to meet sustainability goals, reduce energy bills, and extend equipemnt life by allowing them to more easily meet temperarature and airflow demands. We offer free ROI calculations where you can get facility specific information to see just how quickly UVGI coil irradiation can start lowering your operating costs: