So, I’ve gone on and on and on about Electrocorp units and why they are the best for your industry’s IAQ issues; from welders to nail salons to schools and universities: everyone should have an Electrocorp air filtration unit.

But why?

Activated carbon is a unique product that, once processed, can be extremely porous. Because of this, it’s often used in air and water purification units. Unlike HEPA filters, activated carbon traps larger particles that just pass through the openings in the HEPA filter. Activated carbon is ideal for trapping odors because of this.

Here are different classifications of activated carbon, in case you were wondering:

Powdered activated carbon (PAC)

Traditionally, active carbons are made in particular form as powders or fine granules less than 1.0 mm in size with an average diameter between .15 and .25 mm.[2] Thus they present a large surface to volume ratio with a small diffusion distance. PAC is made up of crushed or ground carbon particles, 95–100% of which will pass through a designated mesh sieve or sieve. Granular activated carbon is defined as the activated carbon being retained on a 50-mesh sieve (0.297 mm) and PAC material as finer material, while ASTM classifies particle sizes corresponding to an 80-mesh sieve (0.177 mm) and smaller as PAC. PAC is not commonly used in a dedicated vessel, owing to the high head loss that would occur. PAC is generally added directly to other process units, such as raw water intakes, rapid mix basins, clarifiers, and gravity filters.

Granular activated carbon (GAC)
Granular activated carbon has a relatively larger particle size compared to powdered activated carbon and consequently, presents a smaller external surface. Diffusion of the adsorbate is thus an important factor. These carbons are therefore preferred for all adsorption of gases and vapours as their rate of diffusion are faster. Granulated carbons are used for water treatment, deodourisation and separation of components of flow system. GAC can be either in the granular form or extruded. GAC is designated by sizes such as 8×20, 20×40, or 8×30 for liquid phase applications and 4×6, 4×8 or 4×10 for vapour phase applications. A 20×40 carbon is made of particles that will pass through a U.S. Standard Mesh Size No. 20 sieve (0.84 mm) (generally specified as 85% passing) but be retained on a U.S. Standard Mesh Size No. 40 sieve (0.42 mm) (generally specified as 95% retained). AWWA (1992) B604 uses the 50-mesh sieve (0.297 mm) as the minimum GAC size. The most popular aqueous phase carbons are the 12×40 and 8×30 sizes because they have a good balance of size, surface area, and head loss characteristics.

Extruded activated carbon (EAC)
Extruded activated carbon combines powdered activated carbon with a binder, which are fused together and extruded into a cylindrical shaped activated carbon block with diameters from 0.8 to 130 mm. These are mainly used for gas phase applications because of their low pressure drop, high mechanical strength and low dust content.

Impregnated carbon
Porous carbons containing several types of inorganic impregnant such as iodine, silver, cations such as Al, Mn, Zn, Fe, Li, Ca have also been prepared for specific application in air pollution control especially in museums and galleries. Due to antimicrobial/antiseptic properties, silver loaded activated carbon is used as an adsorbent for purification of domestic water. Drinking water can be obtained from natural water by treating the natural water with a mixture of activated carbon and Al(OH)3, a flocculating agent. Impregnated carbons are also used for the adsorption of H2S and thiols. Adsorption rates for H2S as high as 50% by weight have been reported.

Polymer coated carbon
This is a process by which a porous carbon can be coated with a biocompatible polymer to give a smooth and permeable coat without blocking the pores. The resulting carbon is useful for hemoperfusion. Hemoperfusion is a treatment technique in which large volumes of the patient’s blood are passed over an adsorbent substance in order to remove toxic substances from the blood.

Other
Activated carbon is also available in special forms such as cloths and fibres. The “carbon cloth” for instance is used in personnel protection for the military.

Activated carbon is effective and environmentally friendly as it doesn’t off-gas or create it’s own pollutants as it works. It’s a clean air cleaner and that’s the reason Electrocorp and AllerAir use it in all their units.

How Electrocorp and AllerAir use activated carbon is also important. Dwell time is necessary in order to trap and hold ambient air pollutants. Some companies will claim that their units are equipped with activated carbon, but on closer inspection, they only have 1/2 an inch of depth. That’s nothing. Outfit an air filtration unit with 3″, 4″, 5″ of activated carbon and you’ve got yourself a mean air pollutant fighting machine. Add to that the fact that air doesn’t travel in a straight line and often heads through the carbon at an angle, and you’ve got the potential for 8″-10″ of activated carbon for your dirty, stinky air to travel through.

Combine activated carbon with HEPA and any other filtration device and you’re really tackling your IAQ issues. It takes more to clean the air than a good fan and some baking soda (which is a crock, by the way, but that’s for another blog).

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