Creating An Air Purifier: Filtering Out Pollution

Air pollution is a pressing issue, and many are seeking ways to improve indoor air quality. Commercial air purifiers can be expensive, but DIY air filters are a cost-effective solution. A simple DIY air purifier can be made with a box fan, good air filters, and duct tape. The Corsi-Rosenthal Box, for example, is an inexpensive, easy-to-assemble air filter that can help reduce exposure to indoor air pollutants. It uses MERV-13 filters, duct tape, a box fan, and a cardboard box. For higher performance, a HEPA filter can be used, which can capture viruses, wildfire smoke, dust, pollen, and more.

Using a box fan, duct tape, and a cardboard box

The Corsi-Rosenthal box is a popular DIY air purifier that can be made using a box fan, duct tape, and a cardboard box. It is a cost-effective alternative to HEPA purifiers, and some research suggests it may even be more effective in certain ways. The Environmental Protection Agency (EPA) notes that homemade air cleaners are not performance-tested, so it does not recommend them as a long-term solution. However, they can be useful in a pinch.

To make a Corsi-Rosenthal box, you will need four MERV 13 air filters and a box fan. The filters and a cardboard base will make up the box, which will be sealed with duct tape. First, cut a piece of cardboard to serve as the base and tape it to the bottom of the box formed by the filters. Then, place the fan on top, ensuring it is positioned to blow air outward, and securely tape it to form the top of the box. Make sure to tape all corners and leave no gaps for optimal performance.

If your fan has rounded edges that do not line up with the sides of the box, you can cut small wedges of cardboard and tape them over the gaps. Additionally, you can create "shrouds" for the fan's corners by cutting more cardboard wedges and taping them in place. This will prevent backflow through the fan's edges. Only the circle created by the fan blades should be exposed. It is important to ensure that there are no leakages, so use plenty of tape to seal all edges.

The Corsi-Rosenthal box works by pulling air in through the sides of the box and through the filters, then blowing the filtered air out into the room. The DIY purifier can help remove large particles such as dust and pet dander, as well as microscopic particles like viruses. Remember to replace the filters regularly, as the more the purifier operates, the cleaner the air will be if the filters are replaced frequently.

HEPA filters are best for capturing viruses, wildfire smoke, dust, pollen, etc

HEPA stands for High Efficiency Particulate Air Filters. They are highly effective at capturing smaller particles, including allergens and common household pollutants. HEPA filters are best for capturing viruses, wildfire smoke, dust, pollen, and more.

HEPA filters are widely recognised as the best type of air filter for purifying the air in your home. They are capable of capturing particles as small as 0.3 microns, which is about 1/50th the size of a human hair. This means they are effective at removing various types of smoke particles, including cigarette smoke, wildfire smoke, and smoke from cooking. Additionally, they are excellent at reducing larger particles like dust and pollen and even smaller particles like bacteria and viruses.

HEPA filters are particularly beneficial for individuals with allergies, asthma, or other respiratory conditions. They can remove common allergens such as dust, pollen, pet dander, and mould spores, improving indoor air quality and making it easier to breathe. HEPA filters can also capture airborne pathogens, including bacteria and most, if not all, viruses, making them an essential tool in reducing the spread of airborne diseases.

While commercial air purifiers with HEPA filters can be expensive, you can create your own DIY air purifier at home. All you need is a flat fan and a HEPA filter. Simply attach the HEPA filter to the front of the fan, ensuring a tight seal to avoid any leaks. This setup has been tested for over 1000 hours and has proven to be effective in purifying the air, even outperforming many big brands.

It is important to note that while HEPA filters are highly effective at capturing particles, they cannot address all air quality concerns. Once particles have settled on surfaces, an air purifier will not remove them. Therefore, it is essential to combine the use of a HEPA filter with regular cleaning and dusting to maintain good indoor air quality.

MERV-13 filters are recommended for improved air quality

MERV-13 filters are a significant upgrade over typical MERV 8 filters, capturing more particles. They are effective against a range of pollutants, including pollen, fine dust, pet dander, bacteria, viruses, mold spores, and smoke.

However, it's important to note that MERV-13 filters are not as effective as HEPA filters in capturing small virus-sized particles. HEPA filters are the highest-rated filters in terms of MERV levels and offer the best protection against air pollutants. Nevertheless, HEPA filters are typically more expensive and may not be compatible with existing HVAC systems due to the increased load on the fan from the finer filter media.

If you decide to use a MERV-13 filter, you can create a DIY air purifier by combining it with a box fan. First, purchase a 20" x 20" box fan and a MERV-13 filter. Place the filter behind the fan, ensuring that the arrow on the filter's frame points towards the fan blades. Secure the filter to the fan using duct tape or another strong adhesive.

This DIY air purifier is a cost-effective solution to improve the air quality in your home, especially if you are concerned about smoke and airborne viruses.

Corsi-Rosenthal boxes are effective, accessible, and easy to make

Corsi-Rosenthal boxes are an effective, accessible, and easy to make way to improve indoor air quality. The box fan filtration system was designed to be a simple, cost-effective tool to promote accessible and effective air cleaning, especially during the COVID-19 pandemic.

The Corsi-Rosenthal box is a DIY air purifier that can be built with a box fan, some tape, and a few high-quality air filters for a total cost of about $65. The design uses multiple furnace filters (MERV 13 and above) with a large box fan, and it can be assembled in just 15 minutes. MERV stands for Minimum Efficiency Reporting Value, a scale that measures how effectively an air filter captures particles of various sizes. MERV 13 filters can capture particles as small as 0.3 to 1 micron, which is about 1/50th the size of a human hair.

The effectiveness of the Corsi-Rosenthal box has been recognised by experts. Richard Corsi, one of the inventors of the box and an environmental engineer, stated that the boxes are "effective at filtering out air pollutants". Jim Rosenthal, Corsi's collaborator and CEO of Air Relief Technologies, added that the boxes reduce particles carrying the SARS-CoV-2 virus but also reduce other indoor air pollutants.

The Corsi-Rosenthal box is also accessible and easy to make. The box and its filters can be purchased from hardware stores for about $100, and it can be constructed quickly. The simplicity of the design has led to its adoption in universities and homes across the United States.

Activated carbon filters can capture a broader range of pollutants

Activated carbon filters are highly effective at capturing a wide range of gaseous and liquid pollutants. They are used in air purifiers to remove volatile organic compounds (VOCs), which are harmful gases released by domestic and industrial activities. VOCs include nitrogen oxides, carbon monoxide, formaldehyde, and benzene, which are known to be detrimental to human health.

Activated carbon, also known as activated charcoal, is a carbonaceous material that has been treated with high temperatures and chemicals to increase its surface area. This treatment process, called activation, creates a porous structure with a vast network of small pores, enhancing its ability to attract and trap pollutants. The increased surface area provides more space for pollutants to adhere to, allowing activated carbon to capture a broader range of contaminants.

The process by which activated carbon filters capture pollutants is called adsorption. This is distinct from absorption, which involves molecules incorporating into the volume of a solid. In adsorption, pollution particles stick to the outside of the carbon molecule due to its enhanced surface area, or "bed." This process allows activated carbon to trap more pollutants than traditional filters.

Activated carbon filters are also effective at removing impurities from water. They can eliminate common water contaminants, such as herbicides, pesticides, and inorganic compounds. Additionally, they are useful in removing chlorine and other chemicals through a chemical reaction called chemisorption, where chlorine molecules are converted into chloride.

The versatility of activated carbon filters makes them a valuable tool in various industries, including chemical, food, oil, and gas. They are particularly useful in addressing indoor and outdoor emissions, reducing the impact of airborne pollutants, odors, and VOCs on human health and the environment.

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