What is UV (Ultra Violet Light?)
UV is Ultraviolet radiation, an energy band within the electromagnetic energy spectrum. Its wavelength is between that of visible light and x-rays and it has been found to be an effective method for destroying germs in a water supply.
UV destroys germs by causing a molecular change in their DNA makeup that prevents them from multiplying and destroys the ability to spread disease. When germs cannot multiply, they are considered dead.
What is UV dosage?
Different germs can tolerate different amounts of UV light and therefore require varying amounts of UV energy to be destroyed. By definition, dosage is the intensity of UV light multiplied by time. The intensity is the amount of UV energy that the UV lamp produces at a certain distance from its surface per square centimeter of the lamp’s area. The time is the period it actually takes the water to travel inside the UV chamber.
What Factors affect UV performance and effectiveness?
UV light can only be effective if it hits its target. If for example, UV light is prevented from reaching its mark due to suspended solids or other impurities in water, then UV will not be as effective as it can be.
The following are the main obstacles that will reduce the effectiveness of UV disinfection:
• Suspended solids. These will act as an umbrella, ‘protecting’ germs from UV light. Suspended solids should be physically removed from water by pre-filtration before it goes to an UV unit
• Iron/manganese will cause discoloration on the quartz sleeve that surrounds the UV lamp and reduces the transmission of UV light, they will also absorb UV energy. They should be removed from water by pre-treatment or at least reduced to no more than .3 ppm for iron and no more than .05 ppm for manganese.
• When water is hard, scale will eventually build up on the quartz sleeve around the UV lamp and will stop the UV light from passing through. A water softener should be used before an UV unit if the water is hard.
• Other organic and inorganic dissolved substances can also reduce the germicidal effectiveness of UV light and should be pre-treated before an UV unit.
What types of UV Applications are there?
The use of UV systems is found in residential, commercial and industrial applications, as well as in sewage treatment plants. UV can be used in: homes, cottages, hotels, motels, buildings, factories, rinse processes, bottling plants, food processing, cooling towers, breweries, hospitals, fisheries, farms, wineries, and the list goes on.
What are the advantages of UV Water Treatment Systems?
UV has many advantages over other disinfection processes:
• UV is effective and quick. No need for holding tanks and reaction times. No need for storing chemicals.
• UV does not alter the taste of water, which makes it ideal for use in bottling plants and food processing applications.
• UV is safe. NO need to add or handle hazardous chemicals or risk polluting the environment.
• UV is compatible with all other water treatment processes. No need for de-chlorination if using RO systems. In fact, UV enhances the use of other water treatment by keeping them free from germs.
• UV is economical. Almost always, the cost of UV disinfection units is much less than the cost of chemical treatment systems. The cost of service and maintenance of UV units is very low. The electrical running cost of an UV unit in a house is about that of a regular light bulb.
• UV is more effective against viruses than chlorine.
• Easy installation. UV units are very easy to install and require very little space.
What are the limitations of UV Water Treatment?
Excessive bacteria counts in water may require additional UV dosages or chemical treatment. Other factors, such as water temperature, should also be considered. UV units are normally designed to operate best between two and forty degree Celsius. Freezing will cause damage to the UV unit and water temperature higher than forty degree C will cause a reduction in UV energy and therefore, a reduced germ kill ratio.
Are any chemicals required by a UV system? Or is there anything else that I will need to add?
It is recommended by most manufacturers that you use a 20 micron sediment filter because large particles act as a haven for microorganisms, which is what you are trying to destroy. Sometimes multiple sediment filters are required because of the water’s turbidity. This is because color and suspended particles will diminish the transmission quality of any UV light. In these cases, a quality carbon filter is used to filter the sediment first.
Is there anything required before I install an ultraviolet water filter system?
You should make sure that your water tank has been cleaned and disinfected and tested to determine any unwanted biological activity is present. The plumbing lines that run throughout your home (water lines, water heater, etc.) is clean first. In order to do this, you should disinfect the entire downstream system with chlorine. ClearWater Systems includes this Whole House disinfection with each POE installation.
What about Installation guidelines?
UV units should be installed after any water pre-treatment process, just before the cold and hot branch lines. If in doubt about the size of an UV unit that is needed, always use a larger unit rather than a smaller unit. Normally, an 8gpm UV unit will be installed as close as possible to the dispensing point. All the pipes should be treated with chemical shock treatment and flushed thoroughly before an UV unit is commissioned and prior to its use.
UV dis-infection is very quickly gaining ground on other conventional disinfection processes because it is effective, environmentally friendly and economical. UV does not change the taste of water and does not add anything to it. For many applications, it is the ideal choice for disinfecting water.
How long does the UV bulb last?
You will need to replace the ultraviolet light bulb once every 10 to 12 months. While the bulb will last a lot longer then that, its capacity for neutralizing microbes will be diminished after this length of time and so you will want to make sure that it is changed at this point so that it can work as effectively as possible.
Why is the water cloudy/white after a new filter cartridge is installed?
This is because the water needs flow for several minutes once a new filter cartridge is installed. The water’s cloudiness indicates that there is air in your line, housing and cartridge. This is normal whenever you replace a cartridge. After you run the water for a few minutes the cloudy conditions will go away unless your water is VERY cold. In this case the oxygen in the water is what is making your water look cloudy. Either way, it is always a good idea to run the water for a few minutes after you install a new filter cartridge.