Electromagnetic frequencies (EMF) surround us daily, whether from wifi, mobile phones or the fields produced by everyday devices. Electromagnetic waves cycling at the same frequencies as other devices move through space and can cause electronics to fail. Protection from EMF is vital to ensure that your electronics work properly.
What is EMI Shielding?
Shielding an electromagnetic field is a measure of how much power a wave loses as it meets another material. Waves travel at exact frequencies and the power loss is not the same for each wave. Once the wave meets the surface of a shielding material, it will bounce off or the shield will absorb it. Since radiation is a cache of different waves, effective shielding requires you know the frequencies you’re shielding against.
The other important thing is the noise reduction or attenuation you’re looking for. Attenuation is a measure of how much a wave’s amplitude loses when encountering the shielding material. Attenuation measures in decibels and typically ranges from 0 to about 120. Conductive paint falls within the range of a few dB to over 100.
What is an EMF Shield?
The most useful solution to protect devices is to surround them with conductive material. Known as a Faraday cage, these materials evenly spread electric charge around the outer surface of devices. A Faraday cage blocks any incoming waves from interfering with interior electric fields.
Not all shielding materials are the same, so it is important to consider the level of shielding needed. Further, there are different shielding materials available so we need to also consider the devices and areas we’re protecting. The following paragraphs outline the considerations needed when trying to achieve EMF protection for home.
EMI Shielding Materials
Conductive materials such as foils, tapes and meshes are popular choices for protection from emf radiation. Applying these materials; however, is line-of-sight making it easy to miss spots. Small gaps in the Faraday cage can leak electromagnetic interference (EMI) that can disrupt devices. Further, these materials are unfit for shielding large areas making them impractical options to protect your home from EMF.
Conductive Paint
Conductive paint is a great option for shielding electronics and homes. Because they apply as liquid, paints are a great options since they conform to complex designs. What’s more, they are durable, stick to many different surfaces and easily apply over large areas. With options for home interior shielding, conductive paint is now a popular solution for protection from rf exposure.
Conductive paint has three main ingredients: the conductive flake, the polymer binder and the liquid carrier. The conductive flake is what determines how effective the coating will block EMF. The polymer used is what gives the coating its main properties such as chemical resistance, scratch resistance and adhesion. Finally, the liquid carrier such as solvents or water liquifies the coating so it can apply over surfaces.
Paint coverage determines how much material you’ll need to cover a total area. This information is within the product data sheet and assumes a dry film thickness and transfer efficiency. The falsehood about conductive paint is that applying more coats provides more shielding. This in fact is not true as area coverage is more important than film thickness for shielding performance.
How to Choose the Right Conductive Paint
Choosing the right paint for shielding your home comes down to a few things to consider. First, it’s important to know what flake system you need to achieve your desired shielding. You should have an expert take measurements inside the home. These measurements determine the strength of EMF coming into the home.
Understanding the radiation coming into the home helps determine what flake system to use. For example, low frequency magnetic fields require materials like nickel which can shield this type of radiation. Highly conductive flakes like silver work best against high frequency electric fields.
To paint drywall, we suggest a water-based system. These products adhere to drywall without having to use a primer. Further, they have low odor and will not linger in your home for long. They are also non-flammable so long-term storage is not a fire hazard.
Cost is a significant factor to consider when shielding your home. The raw materials cost of the conductive filler differ by quite a lot which affects the cost of the paint. Rather than looking at the cost of a container of paint, it is instead best to calculate the cost of painting a given area. To do this, we need to consider the coverage of the paint.
In this example, consider a simple 10′ by 10′ room with 9′ ceilings. The total area that needs paint is calculated below. floor and ceiling = 2 x (10’x10′) = 200ft2 walls = 4 x (10’x9′) = 360ft2 total area = 560ft2 If the coverage of the paint is 130ft2/gallon, we can calculate that we need just over 4 gallons of paint for this room. Use this approach to estimate how much it will cost to paint the rest of the house.
How to Shield your Home from EMF
People concerned about EMI can shield their homes by applying conductive paint on the interior walls, ceiling and floor. These coatings apply directly onto the drywall without having to use a primer. Further, you can paint over with water-based paint for desired esthetic. You can apply the paint throughout the entire house or confined to individual rooms.
Since the objective is to make the room a Faraday cage, you also have to apply the paint on the ceiling and floor. If the room is on the ground floor, it may not be necessary to paint the floor. Windows are another thing to consider as painting them would block sunlight from entering the room. Here, you can use conductive curtains to block EMI coming through the window.
You will also need to ground the walls after applying the shielding paint but before applying any topcoat. This is a task for qualified experts to make sure it’s correct.
Important to note that wireless devices connected by wifi will not work in painted areas. Wireless signals cannot reach and communicate with electronics within a shielded area. Devices like mobile phones, laptops and smart TVs will not work in shielded rooms and will have to move elsewhere. Electronics use here is strictly for devices that are hardwired.
MG Chemicals has a full range of conductive coatings, including water-based coatings meant for home protection. Please use our resources to help learn more about these products. Should you need more help, please contact Technical Support.
