In-Line UV Vs In-Tank UV Disinfection – Which is Better?
UV disinfection of water is considered the most effective technique to keep water safe from microorganic contaminants like bacteria, viruses, etc.
This post will provide you with complete details on why UV is so effective in water purification, in-line and in-tank UV disinfection, their differences, and which one’s better.
WHAT IS UV DISINFECTION?
In simple terms, UV Disinfection is water disinfection using UV light.
In UV water disinfection, Ultraviolet light is used to disinfect water from harmful microorganisms like bacteria, viruses, protozoa, algae, etc. UV disinfection is the most cost-effective and highly effective technology to fight microbial contamination in water.
UV disinfection is also the safest way to get rid of harmful microbes that grow and multiply quickly.
Any light with a wavelength in the range of 200 to 400 nanometers is referred to as Ultra-Violet light.
How Does it Work?
In the UV water disinfection technology, the UV light disinfects the water by destroying the DNA of microorganisms.
DNA controls the growth, functioning, and reproduction of all living organisms.
UV light produces electromagnetic energy that destroys the reproduction ability of microorganisms. The UV light also causes the inactivation of microbes due to mutations and/or cell death. (Source: Violet Defense)
This UV energy is also naturally found in sunlight in very small quantities. That’s why, in old times, water was kept in direct sunlight for disinfection.
The same UV light in much stronger intensity is now produced with the help of high mercury discharge lamps, commonly known as UV lamps.
Benefits of UV Disinfection of Water
- Environment friendly, no wastage of water
- No chemicals, very safe, no side effects
- Affordable and very effective
- Works instantly
- Proven to kill most microorganisms found in water like bacteria, mold, fungi, and even viruses
What is In-Line and In-Tank UV Disinfection?
The underlying technology, i.e., using a UV light for water disinfection, remains the same in both in-line and in-tank UV disinfection.
The only difference lies in the placement of UV light.
In in-line UV disinfection, water is passed through a UV chamber first and then stored in the purified water storage tank.
Whereas, in in-tank UV disinfection, the water is disinfected in the storage tank. As the name suggests, the purifiers with in-tank UV have a UV light in the storage tank.
Difference Between In-Tank UV and In-Line UV
| In-Tank UV | In-Line UV |
|---|---|
| Purified water is disinfected with a UV light in the storage tank. | Purified water is disinfected with UV light before storing in the tank. |
| The stored water is safe from microbial infection. | There are chances of microbial infection if the stored water is left unused for a long time. |
| No need to empty the storage tank after returning from a short family vacation. | The tank needs to be emptied when purified water is left unused in the storage tank for a few days. |
| The water is disinfected several times, as long as it remains in the storage tank. | The water is disinfected only once. |
In-Line or In-Tank UV Disinfection – Which One is Better?
The water stored in the tank for a long time is not safe to drink as it is prone to bacterial infection. If the purified water is left unused in the storage tank, you need to empty the storage tank completely before re-filling the storage tank.
This is where in-tank UV is beneficial. In in-tank UV systems, the UV LED light is automatically turned on and off at fixed intervals. This keeps the stored water safe from microbial infections. With in-tank UV disinfection, you don’t need to empty the storage tank even if you are on a short family vacation.
On the other hand, the in-line UV system disinfects the water only once, prior to storage in the tank, when it passes through the UV chamber. In-line UV works fine, as long as the purified water is not left in the storage tank for a long time.
Here is a list of some RO Purifiers that use in-tank UV disinfection.
The Bottom Line
In-Tank UV disinfection is comparatively better than in-line UV disinfection as it not only provides safe drinking water but also keeps the stored water safe from microbial infections.
Can I install a bare 11w UV lamp inside my water tank? Will cause any damage to the UV lamp due to moisture?
The UV LED that Kent uses in their water purifiers with an in-tank UV feature is just 0.7W. Installing an 11W UV lamp in the storage tank may not be safe keeping in mind the risk of exposure. Also installing a bare UV lamp in the tank is not recommended because of safety and durability.