How To Make An Efficient Air Purifier Using Box Fans

People today that suffer from allergies and breathing problems already know that decreasing air quality is only making them sicker. On the other side of the equation, actually improving air quality in the home may seem like a hopeless task because it impossible to get rid of all the air leaks and drafts.

In most cases, these drafts aren’t the actual problem. Rather, it is the lack of good air flow throughout the building that allows dust, toxic gasses, and other pollutants to build up. This is just one of many reasons why you may benefit from building a DIY air purifier based on a box fan.

Why You Need to Purify the Air in Your Home

Even if you aren’t suffering any effects from air pollution, it is still important to make sure that you can remove any number of toxins in the air during a major crisis. For example, a major wild fire outbreak, gas attack, nuclear attack, and other problems will either force you to wear a gas mask all the time, or be able to control the air quality enough so that you do not need to wear a mask.

While the basic DIY air purifier described in this article will not filter out 100% of toxins all the time (this version filters out about 50 – 70% depending on the pollutant and the filter lifespan position), it will give you enough difference in air quality to manage a number of situations.

In addition, with a a few changes in the filter media and changes to the air flow in your home, it forms a vital basis for any air purification system that will have close to a 100% efficiency level.

DIY Box Fan Air Purifiers vs. Pre-Built

As a means of summary, DIY box fan air purifiers are more efficient and have greater potential for expansion across every comparable measure when compared to pre-built air purifiers that you commonly see in department stores. Have a look at how a 20 x 20 box fan can easily beat just about every model on the market for a fraction of the cost:

CFM (cubic feet per minute) – this is the amount of air that the unit is capable of circulating through the filter apparatus. The higher the CFM, the better. Most small air purifiers only produce about 100 CFM, while larger units designed for medium sized rooms will produce about 400 CFM.

By contrast, a 20 x 20 box fan on its highest setting will produce about 2500 CFM. You may lose around 400 – 500 CFM when using higher capacity filters, however even at that reduction, the CFM is easily 3 – 4 times more than the maximum output of more expensive options.

Filter surface area – in general the greater the surface area, the better the filter will be at capturing particles without clogging up or impeding air flow. Most conventional air purifiers on the market have decidedly puny air filters that measure well under 10” x 10”.

In fact, most purifiers have filters that are around 6” x 8” or 9”. On the other hand, when you fit a filter for a box fan, the most active area will extend across the entire diameter of the blades. In most cases, this is about 15 – 16” across (including the subtraction for the fan motor vent area).

This Device Easily Turns Air Into Water!

Here, you have double the surface area with good air movement across the area. Depending on how you arrange your filter layers, it is also very easy to double or even triple this extended surface area and even recapture some of the lost CFM.

Easy to customize – no matter whether you need to get rid of gasses and fumes with activated carbon, get rid of bacteria, or manage mold, pollen and mildew, there is likely to be a filter or combination of filters that will meet your needs.

While pleated filters tend to allow a larger surface area, do not overlook padded versions that offer excellent air flow, and sometimes a lower cost. By contrast, when you buy a conventional air purifier, you must also purchase the pre-made filters. If the manufacturer does not offer a permanent filter, an activated carbon pre-filter, or decides to stop making replacement filters altogether, you will be stuck with a useless unit.

Box fans and filters are much cheaper and last longer. Conventional air filters will cost a minimum of $60.00 off the shelf for a relatively small unit. On the other hand, a brand new box fan costs about $20.00.

A good quality 3M Merv 12 filter with an electrostatic grid costs about 15.00, and an activated carbon pre-filter costs between $10.00 and $20.00 depending on the brand and design. If you decide that you want a HEPA grade (Merv 13 and above), the cost per filter ranges between 12.00 per filter and up, depending on where you buy them and the quantity.

Your total cost for a DIY box fan filter can be as low as $40 – 50.00 (including incidentals like duct tape), or higher depending on the filter options. Insofar as filter changing costs, you will find that it is still much cheaper to buy furnace filters and variants of them without sacrificing on quality or air cleaning capacity.

Speaking of filter ratings, most air purifier manufacturers only state that the filter is a HEPA filter. While you may assume this means the filter is at a hospital grade or above, they may be using a filter that is barely above the top level filter you would use for your heating system.

On the other hand, when you buy filters for your box fan, you will always know the exact efficiency rating. Depending on the manufacturer, you may also be able to see the test results for each filter.

Filter Options and What They Mean

Before you decide on a specific filter or combination of filters, it is very important to know how they are rated and what you can expect.

Efficiency Ratings – this refers to the particle size that can be removed by the filter. Typically, the higher the efficiency rating, the more particles the filter can remove without becoming clogged up. Higher efficiency ratings also give you some information about the size of the particles that can be captured.

Filters with a higher efficiency rating can capture a higher percentage of smaller size particles. For example, a MERV 10 filter may capture as much as 70% of pollen and mold spores, but only 20% of bacteria, while a MERV 12 will capture as much as 90% of pollen and mold, but as much as 40% bacteria.

This article has been written by Carmela Tyrell for Survivopedia.

“Visit Survivopedia.com – a growing encyclopedia for survival, your ultimate source of uncommon wisdom for dangerous times.”