Ultraviolet (UV) sterilization is a popular method for eliminating microorganisms in water. It is used in both Point-of-Entry (POE) and Point-of-Use (POU) water filters. POE systems are installed at the main water supply line, while POU systems are installed at individual faucets or appliances. As a result, they incur lower energy costs than POE systems.
For instance, the Crystal Quest CQE-UV POU water filters use much less energy than UV POE filters. On average, they consume between 10 and 15 watts. The average household consumes around 1 kWh per day. When it comes to UV sterilization, not all types of UV rays are effective. To be more precise, ultraviolet (UV) means “beyond violet” and refers to a range of electromagnetic waves with a shorter wavelength (higher frequency and energy) than visible violet light.
UV rays are divided into three types: UVA, UVB and UVC. For UV sterilization, only UVC (100-280 nm) has a high enough energy to effectively kill microorganisms. When you purchase a UV sterilization product to test in your home or business, make sure that its UV wavelength is within the UVC range (100-280 nm). UVA bulbs emit wavelengths between 315 and 400 nm, while visible light bulbs emit wavelengths between 400 and 700 nm. This wavelength is between 290 and 315 nm, which is why UV bulbs are often referred to as “UVC” or “UVB”.
Since UV sterilization uses the energy of UVC rays to destroy biomolecules, its effectiveness depends on the total energy applied, which is affected by the exposure time and the distance from the light source.
