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Ultraviolet light is the short-wavelength of the violet end of the spectrum. This is not visible to your naked eye. UV light has been used in the industry of disinfection of bacteria, fungus, and mold among other microorganisms. So, does UV light kill mold?
UV light kills mold by producing radiation that destroys fungal cells. As such, UV light is used to get rid of mold in AC units, ducts, and crawl spaces. To kill mold spores using UV lamps, simply flood the area you want to disinfect with ultraviolet light only.
UV light and even UV from sunlight kill mold that is not so deep-rooted into the materials that it is growing on when exposed to UV light, it will effectively be killed. Also, enough exposure of mold to UV light kills mold and mold spores in the air.
Does a UV Light Kill Mold Spores?
The effectiveness of UV light is also dependent on the size of the mold colony, its location and the amount of exposure to the UV light. The distance between the mold infested area and the source UV light also determines the effectiveness of the UV light. For instance we have mold growing on surfaces, such surfaces when aired under the sun or exposed to a UV lamp, the mold shall be effectively killed.
The UV light produces electromagnetic energy that destroys the DNA and RNA components of the microorganisms. This effect of UV light on mold makes them unable to grow or reproduce and they eventually die. Using UV light is effective in killing airborne and visible mold spores.
UV light has been proved to effectively kill mold. This occurs when the UV lamp has been placed in area and engulfs the whole area, making it impossible for mold spores to grow.
READ MORE: Do Ozone Generators Kill Mold?
Also UV lamps can be installed in HVAC system. It shall be able to keep all the HVAC system free of mold, a very effective way of getting rid of the mold menace.
It is advisable that you make the use of UV light a regular routine for killing mold spores in your home. This is so because it is effective and not harmful to the environment or people.
After mold remediation, it is efficient for one to use UV light to kill any mold spores that might have escaped into the air.
The intensity of the UV light will determine its effectiveness. The higher the intensity and the more the length of exposure to mold surfaces, the more effective it becomes.
What kind of UV light kills mold?
The type of UV light that’s able to kill mold is UV-C, which has a short wavelength. UV-C lamps are effective at disinfecting air ducts, air conditioners, and other indoor spaces that attract mold spaces.
UV-C lamps are also called germicidal lamps because they are able to disinfect even air and non-porous surfaces. When used properly, a UV-C light sanitizer can help keep your house clean and free of germs and other pollutants such as mold.
Here are some of the best UV-C lamps to buy:
- Germ Guardian Pluggable Air Purifier & Sanitizer
- Freshr Portable UV-C Sanitizer
- Dsane UV Light Sanitizer with Quartz Ozone Lamp
UV-C is a very short length of UV light that works by disrupting the nuclei of microorganisms, prevent mold from reproducing and kills them eventually. UV-C light also disorganizes the DNA of the mold and leads to a defect in the cell reproduction of the mold and eventually the mold cell will die.
There are HVAC UV lights that can be installed in your HVAC system to kill mold and mold spores in the whole system.
Does Sunlight Kill Mold?
Sunlight has a lot of benefits. And yes, it does kill mold and mold spores. You notice that mold grows in dark humid areas of your home. When mold and mold spores are exposed to sunlight, they die gradually.
Also, we have noticed that the main source of UV light is the sun, meaning the UV component of the sun will kill mold and mold spores. Another important factor is that mold grows in damp areas, and the sun dries such areas out, this will imply that mold will not grow in areas that are well lit.
The sun emits heat, leading to warm temperatures, we are alive to the fact that mold thrives in damp wet areas. With the heat that is emitted from the sun, it makes it hard for mold to grow. So in a way sunlight kills mold and the mold spores by exposing them to high temperatures.
READ MORE: How to Get Rid of Black Mold in Air Vents
For sunlight to be effectively used to kill mold and the mold spores, you need to air the affected items directly under sunlight. You need to clean the affected areas first by using the recommended cleaning agents. When it comes to drying these items, place them directly under the sun. The sun shall effectively kill all the mold and mold spores that might have been left behind after the cleaning, also, sunlight shall eliminate any form of moisture.
How Does UV Light Destroy Mold and Bacteria?
Mold is a type of fungus that grows in certain conditions and can cause damage to your home. One way to get rid of it is by using UV light, which kills the mold by breaking down its DNA, or genetic material.
UV light is a type of radiation that’s invisible to the human eye. It breaks down DNA and kills cells so they cannot replicate in living organisms – including mold spores.
UV lamps are used as an economical treatment for destroying molds on textiles and other materials with no toxic chemicals necessary. They can also be found in hospitals because they do not create any harmful byproducts like bleach or chlorinated water would when treating diseases like Hepatitis C virus (HCV).
The lamp emits electromagnetic waves which kill bacteria without altering their genetic material or creating mutations. A UV-C treatment will destroy 99% of viruses within seconds.
- An electric field is created between two electrodes inside the lamp.
- When the electric field is turned on, electrons are released from an electrode called a cathode and stream towards another electrode called an anode.
- Free ions in gas form near the electrodes which creates UV light waves or photons of various wavelengths. The wavelength determines how deeply into cells it can penetrate to destroy viruses and bacteria inside.
The UV-C lamp is most effective against viruses and bacteria which grow close to the surface of cells.
Pro tip: Germicidal UVC lamps should be used for cleaning surfaces that are visibly dirty or soiled, but not when you suspect mold on porous materials such as carpeting because it can damage these types of material.
How to Kill Mold with UV Light
The first step do is to obtain a UV-C lamp. Purchase the lamp which should be convenient with area that you intent to use it for. Identify the surfaces that are infected with the mold.
Then you need to wear UV opaque goggles. Since UV light is harmful to your eyes and can cause blindness, the goggles shall protect your eyes.
It is recommended that you need to place the UV lamp at least 2 inches away from the surfaces with mold. Also, you need to put out all other sources of light in the room and close all windows and doors. This will ensure that only the UV light is emitted into the area to effectively kill mold.
You need to leave the UV lamp on for about 2 hours, then switch it off. After the 2 hours, change the position of the UV lamp, that is, move it to another area where there is mold or mold spores. Also, make sure that the UV lamp is placed slightly away from any wall.
You need to do this in all the rooms that you suspect to have mold. Also, do it occasionally so that you completely eradicate the mold and mold spores.
If you notice that your UV lamp has dust or dirt particles collected on it, you need to have it cleaned otherwise it would be ineffective.
It is important to bear in mind that the UV light does not remove the stains caused by mold. The stains have to be removed by way of cleaning.
We have defined what UV light is, its source and how it kills mold together with the mold spores. We have also looked at how sunlight kills mold and mold spores.
- FDA: UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus
- Sarah Thompson, Cornell University: UV light may be ripe to replace chemicals in fungus fight
- United States Environmental Protection Agency: Does ultraviolet (UV) radiation from UV lamps kill mold?
HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.