If you haven’t already please take a moment to read our introduction to this series, as well as part 2, which covered the topic of Medium Pressure UV. To wrap up the series we’re discussing Low Pressure and Low Pressure Amalgam UV systems.
Low Pressure UV (Abbreviated to LPUV)
LPUV is best suited to “low” to “moderate” flow systems (up to 400-500 GPM typically). The lamps of the LPUV systems output UVC (the UV wavelength)at 254nm. This is the ideal wavelength for microorganism deactivation and for destruction of mono-chloramines. LPUV systems give off more of the desirable germicidal light than Medium Pressure and typically are about 40% efficient.
LPUV runs much cooler than MPUV (Medium Pressure UV). Due to this, LPUV housings can be constructed with non-metallic materials (HDPE & PVC are the most common). Some LPUV systems are constructed of stainless steel, and some of those have the same TDS limitations of MPUV, but not all do. You best bet is to check that out before you decide on a system.
LPUV is generally very “compatible” with all sanitation systems, allowing operators to run any sanitation system they’d like in conjunction with the UV (eg: Inline Chlorine Generators, Brine chlorine Generators, Liquid Chlorine, Dry chlorine, Gas chlorine, etc.) *Coming from a chlorine generator background, TMI typically installs Low Pressure units for our clients with salt pools, although this is not the only option.
LPUV systems are typically installed as a treatment/management option for chloramines with the added benefit of microorganism deactivation. LPUV does not create a chlorine demand on the system as the output is generally designed and sized for 45-60mj/cm2.
LPUV is the least expensive option of the three. Materials and lamps are generally a fraction of the cost of the Medium Pressure systems, and are slightly less than Low Pressure Amalgam(LPAUV). LPUV lamps also last the longest with 13,000-16,000 operating hours, when compared to MPUV’s 1000-2000 Hours, and LPAUV’s 10,000-13,000
Typical Applications for LPUV include: Any pools with salt chlorine generators, High Schools, Health Clubs, Swim Schools, hotels, Condo Associations, Small Water Park Pools, and more.
Low Pressure Amalgam UV (Abbreviated LPAUV)
LPAUV is similar to LPUV in that it produces UV light in a narrow band at 254nm, however, the intensity is greater, generating over 60mj/cm2 dose rates. LPAUV is slightly more expensive than standard LPUV and is not quite as efficient, coming in at around 35%. LPAUV does get much warmer than standard LPUV, which results in most LPAUV systems being constructed of stainless steel to withstand the heat.
Some LPAUV systems have the same limitations on salinity and TDS as their MPUV alternatives, which is something that must be taken into consideration before purchasing.
Lamp Life is similar to LPUV albeit slightly lower, with an average of 10,000-13,000 operating hours.
Typical Applications for LPUV Include: High Schools, Health Clubs, Swim Schools, Collegiate Pools, Small Water Park Pools.
So there you have it. These are the three main options today in the business of Ultraviolet systems for commercial aquatic facilities. We hope you’ve learned something new and that perhaps we’ve helped you down the path to the right UV system for your facility. Do you have a UV system already installed? Are you looking into getting one? Let us know what you think and what your experiences with UV systems have been.