A simple way to purify the air at home! Let's make a Corsi-Rosenthal Box? (What Is a Corsi-Rosenthal Box?)

We all spend most of our days indoors, right? So keeping the air inside our homes clean is very important for our health . This is especially important for those who have allergies to dust, small children, or those who often get colds. The best air purifiers on the market, namely those with HEPA filters, are a bit expensive. But would you believe me if I told you there was a good, low-cost solution?

What is this Corsi-Rosenthal Box?

Simply put, this is a very simple, yet very effective air purifier that we can all make at home. It was introduced by American engineer Richard Corsi and filter company CEO Jim Rosenthal. The name Corsi-Rosenthal box is derived from their names.

Imagine, you can make this for less than a third of the cost of a more expensive machine, with a few items you can buy from a regular hardware store. All you need is a box fan and four good air filters. Some research has even found that this simple device can be more efficient than some expensive HEPA machines in some ways.

Now let's look at what this `(MERV)` means. It is a measure of how well a filter captures small particles in the air. The higher the MERV value, the more efficient the filter.

How does this device work?

The operation of this is very simple. We install four filters on all four sides of the box we are making. The fan on top pulls the air from the room through these four filters, cleans it, and blows it back into the room from above.

At first, researchers were surprised how this simple box could clean the air faster than an expensive `` HEPA '' filter. Because, in a single pass, a HEPA filter can capture much smaller particles.

Experts think the reason for this is as follows:

"The air flow from these box fans is very high. Much higher than a typical commercial HEPA machine," explains Rosenthal. "So the air goes through the filter several times in the same amount of time. Maybe the first time it will only capture 50% of the particles. But the second time, the third time, it will clean a lot more." That means at higher speeds, more times.The secret here is that the air is clean.

How successful is this really?

Several studies on this have yielded good results .

• In one study, Corsi-Rosenthal boxes were used in a university building. Within two months, the levels of chemicals called ``PFAS``, which are found in cleaning products and fabrics, in the air were reduced by 40% to 60%. Similarly, the levels of chemicals called ``Phthalates``, which are found in perfumes and building materials, were reduced by 30% to 60%.
• Another small study found that the air purification rate of this device, known as the Clean Air Delivery Rate (CADR), is significantly higher than that of a typical HEPA machine. This means that it can clean the air in a room faster .

But we need to remember one thing. The best ways to keep the air inside your home clean are to remove sources of pollutants (like smoke, harsh chemicals) and to open windows and ventilate well. A device like this is an additional help in that. Wearing masks and maintaining social distancing are still essential to protect against viruses like COVID-19.

How do we make one like this?

The materials needed for this can be found at any general hardware store. It's also very easy to make. It's as simple as taping a parcel.

How to make:

1. Make the four sides: First, place the four filters together and tape them together to form the four sides of a square box. The most important thing: Each filter has an arrow indicating the direction in which the air comes in. You need to place all four filters with that arrow facing inward .

2. Attach the bottom: Now cut a piece of cardboard to fit the bottom of the box, and tape it tightly to seal it.

3. Place the fan on top: Now place the fan on top of the box. You want to place it in a way that the air is blowing out of the fan. Then place the fan firmly in the box and seal it with tape.

4. Seal the gaps: Sometimes, the corners of the fan are rounded, so there can be small gaps. If that happens, cut small pieces of cardboard and seal the gaps well with tape. Do not leave any gaps , that is how you get the maximum efficiency .

The whole thing takes about 15 minutes.

How long can this be used?

You can leave this on whenever you want, but if you continue to use it, the number of times you need to change the filter will increase.

It depends on your environment. Is there a lot of dust in your home? Do you have pets? How many hours a day is it on? These things will affect the filter replacement time. In a generally clean environment, if you only use it during the day, it can last for about 15 months.

You don't need to change the filter as soon as you notice that it's a little dirty. But if it's very dirty and black, it's a good idea to change it. Changing the filter is also very easy. Without removing the cardboard underneath and the fan, you just have to cut and remove the old filters on the four sides, and install the new filters with some tape.

How does this sound?

It's generally quieter than a home fridge, but it's a bit louder than some of the more expensive air purifiers on the market, especially when the fan is turned up. But since it's a continuous 'white noise', it may not be a problem in some environments.

So, if you are concerned about the air in your home, especially if you have allergies, you can try this simple, low-cost method. But remember, if you have a serious allergy or asthma condition, it is important to talk to your doctor before doing anything like this.