My Opinion and the Dirty little truths about HEGA filter.
Unfortunately, the word “HEGA” has also become diluted amongst our industry and surprisingly to me from companies that know better.
What is a HEGA? “High Efficiency Gas Adsorber”, the adsorber must have a minimum mechanical efficiency of 99.9% when tested in accordance with the Institute of Environmental Sciences designation: IES-RP-CC-008-84, “Recommended Practice for Gas Phase Adsorber Cell.” In addition, the adsorber must be designed, built, filled and packaged in accordance with the intent of this standard. Since HEGA filters are manufactured in several different sizes and of several different materials, this standard is not always followed exactly. It is the intent of the standard and the resulting performance of these adsorbers that is important.
This type of adsorber is not intended to be used in odor control systems.
The HEGA was designed for extreme conditions to protect people in shelters and to protect them from biological warfare as well as Nuclear areas. HEGA’s are typically 12” to 18” in depth and hold from 58 pounds to 105 pounds of activated carbon and cost several thousand dollars for a single 24” x 24”x 12” filter.
The New HEGA filters being produced by some major companies are more for odor adsorption. They are not a bad filter however they should have never been called a HEGA and would never pass the IEST Standard.
I will refer to them as New Generation HEGA’s which may contain up to 600 grams of carbon per square meter of filter area for the maximum available content. Current literature shows that a 24 x 24 x 12 will have a maximum of 126 sq. ft of media or 11.71 square meters. 11.71 sq. meters X 600 grams = 15.48 pounds of activated carbon.
A true 24 x 24 x 11.5 HEGA would hold a minimum of 58 pounds of material where as the New Generation HEGA holds a maximum of 15.48 pounds of carbon for the same dimensional size.
The new generation filter is a great filter, well made and many uses. My main issue is that it should have been named something else. Don’t sell me a VW Jetta and tell me it’s a Ferrari …..
Activated carbon filters are worth several pages of discussion as it’s own topic. So buyer beware if you want a true HEGA filter. When Carbon works well it can hold up to 1/3 of it’s weight in fume contaminant. So 9 pounds of carbon could hold 3 pounds of fume. If some one wants to sell you a HEGA and it comes in a portable air cleaner it is not a true HEGA. If you can install it into your current AC system Or commercial AC system with no fan modification it is probably not a true HEGA. Some companies will tell you that they have such a fine granual of carbon that they have a massive surface area. I agree with them, however carbon applications require that you provide enough carbon by weight and that the air or liquid you are treating needs to have adequate residence time in the activated carbon for the adsorption process to take place.
To learn more about activated carbon contact me at Clean Liquid Systems. We will be happy to save you money on new generation carbon filters as we can offer them to you with substantial savings vs. the big guys.
Don Palermo CAFS