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Home » Water Filtration Systems » How Does a UV Water Filter Work?

How Does a UV Water Filter Work?

By: Craig Smith
Last Updated:
how does a uv filter work?

If you are like most people, you are probably more eager than ever to find ways to minimize your exposure to harmful contagions such as viruses and bacteria.

One way that you can go about doing that is by installing a UV filter.

A popular method for significantly reducing the number of waterborne pathogenic organisms in drinking water is to purify it by using advanced UV (ultraviolet) light technology.

But how exactly does UV Filtration work and what does it remove?

I will use my 26 years of experience in water purification to explain this to you in more detail.

We will discuss:

  • Some Basics About UV Light Disinfection
  • The Differences Between Water Purification and Filtration
  • The Types of Contaminants UV Light Significantly Reduces or Eliminates
  • A UV Light Water Disinfection System’s Key Components
  • The UV Light Water Purification Process

Some Basics About UV Light Disinfection

Before you can learn how a UV water filter works, it will help you to know a little more about what UV light is.

UV is a spectrum of light that comes to us naturally from the sun’s rays or it can be artificially created.

This spectrum of light operates in three wavelengths. These are the UV-A, UV-B, and UV-C light spectrums.

The most powerful of which is UV-C light and that’s why it’s also often referred to as germicidal UV.

UV-C is the type of ultraviolet light that all UV light-based water purification systems use.

The Difference Between UV Water Purification and Filtration

While water treatment systems that use ultraviolet light are commonly referred to as UV light water filters, that’s somewhat of a misconception.

A UV light water purifier has just one main purpose. That’s to act upon waterborne pathogenic organisms in such a way that they no longer pose a threat to a human body.

On the other hand, water filters are tasked with filtering solids and chemicals out of drinking water and they also eliminate foul odors, bad tastes, and turbidity.

A UV light water purifier is not capable of filtering solids and chemicals out of the water.

These are also the reasons why UV light-based water disinfection systems must be used in tandem with water filtration setups that come before them in the waterline.

The Types of Contaminants UV Light Reduces

bacteria in water

Why are UV light water purification systems becoming more popular?

It’s because they are very good at rendering ineffective the following pathogens that are commonly found in home drinking water:

  • Some viruses
  • Giardia
  • Dysentery
  • Cholera
  • Mold spores
  • Cryptosporidium
  • Yeast
  • Salmonella
  • Mycobacterium tuberculosis
  • Algae
  • Streptococcus
  • E. coli
  • Fungi
  • Hepatitis B

Many of the waterborne pathogenic organisms on this list can cause serious illness or even death if they are allowed to accumulate in significant numbers in you or your family members’ bodies.

UV Light Water Disinfection System Key Components

Another important aspect when learning how a UV water filter works is knowing the key components that make up the system. These components include:

1. Control Unit (also called the Ballast in UV systems that are on continuously)

For a UV light water purification system to work, you will need an electricity source. That’s where the unit’s corded control system comes into play. When it’s plugged into an outlet, it will supply the needed electricity for the system.

Depending on the sophistication of the UV water disinfection system that’s purchased, this component will also control such functions as powering the system on & off and programming the times the unit is to run (if desired – it can run continuously with no problems). Another cord will also run from the control unit and attach to the exposed end of the UV lamp.

2. UV Chamber

This is the heart of any UV light-based water purification system.

It’s where the disinfection process of the water that passes through it takes place.

It features a water inlet at one end of the chamber and a water outlet at the other. The end of the chamber where the water inlet is will also be open. This is to allow the all-important UV Lamp to be inserted inside of the chamber.

3. UV Lamp

This is the system component that produces the germicidal UV-C light.

These lamps will come in different shapes and sizes depending on the manufacturer and the power of an individual UV water purification system.

The lamp itself is placed inside a quartz sleeve. Then it’s inserted into the open end of the UV Chamber and makes a watertight seal through the use of O-rings or rubber washers. The cord from the control unit will attach to the end of the UV lamp that protrudes out of the UV chamber to power the bulb.

uv system diagram

The UV Light Water Purification Process

Although they are very effective when it comes to eliminating microbes and microorganisms from your drinking water, it must also be said that UV light-based water purification systems are not extremely complex devices.

Here is how the UV filtration process works:

1. First, the UV Chamber must be spliced into your water feed line. It can be done in such places as underneath your kitchen sink or next to where your water feed line comes into your home. Much of where the UV chamber is inserted into the water feed line depends on its size.

Once the UV chamber has been installed, water will continually pass through it by going into the UV chamber inlet and returning into the water feed line through the UV chamber outlet.

This flow of water will take place continuously regardless of whether or not the UV water purification system is turned on or off.

2. The system’s control unit will also need to be mounted to a surface near the UV chamber that has a power outlet nearby or it can be hard-wired into an electrical box.

3. Once the system has been turned on, the UV lamp will illuminate and automatically start producing disinfecting UV-C light. This will treat 100% of the water that passes through the UV chamber.

4. Next, the UV lamp’s germicidal rays will start to work their magic. It must be noted that UV light does not kill pathogenic organisms on contact. Instead, it penetrates into them and alters their DNA.

This process is called thymine dimerization. It prevents microbes and microorganisms from reproducing and thus renders them incapable of infecting a host.

A Simple but Effective Means of Water Purification

I hope that you enjoyed reading this article and that now you have a better understanding of how a UV light water filter works.

As was mentioned, UV light-based water purification systems offer a very simple but impactful method for neutralizing the waterborne pathogenic organisms that are found in your home’s drinking water.

They are also very affordable in most cases. This is true even when it comes to larger systems meant for bigger homes and businesses. I have one in my home and I encourage you to consider doing the same. You can never be too proactive when it comes to making your home’s drinking water as safe as possible.

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Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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