Pentek Big Blue Carbon Filters

See individual products for product datasheets and additional information. There are other products offered that also factor in total purchase price.

How to choose the right carbon filter

In choosing the correct carbon filter, you should consider the following factors: size of the filter, cost of the filter, total capacity of the filter (life), application (taste and odor reduction, chlorine reduction etc) and flow rate (pressure drop).

If you are replacing the filter in an existing housing, you should measure the diameter (width) and length of your existing filter. Standard filter cartrdiges are 2-1/2" to 2-5/8" long and 10, 20, 30 or 40" in length. "Big Blue®" sized filter cartridges are 4-1/2" in diameter and 10 or 20 inches in length. Big Blue® sized filter cartrides are generally chosen for their higher capacity and longer time intervals between changes (rather than higher flow rates). If this is a new installation, you should choose the size of cartridge based on your desired budget and length of filter change interval. Although length and diameter of the filter can have some impact on flow rates and pressure drops, the type of filter is a more imporatant factor. You should always check product datasheets for recommended flow rates and pressure drop values at those flow rates.

There are many different types of carbon filters available depending on cost, function, acceptable pressure drop and capacity.

Carbon filters without particulate removal

Siemens recommends the RFC series of cartridge for odor and taste improvement or chlorine reduction applications. The RFC series of filter has the lowest pressure drop of any carbon filter and the highest capacity. The RFC series does not filter any particulates and has a high cost but is generally worth it. PENTEK® GAC, CC and CGAC series filters offer high capacity like the RFC series filters but because of their design they create more pressure drop than the RFC series. Always consult the filter datasheet on each product page for a chart of pressure drop at different flow rates. Choosing a filter with a high pressure drop can substantially reduce or stop the flow of your water depending on your total water pressure.

Also available are GAC style filter cartridges like the GAC, CGAC and CC-10 series. These filters have a higher pressure drop than the RFC series but can be a better filter for chlorine reduction in some applications because of the amount of contact time between the water and the carbon.

Carbon filters with particulate removal

Carbon filters that also remove particulates can be useful in reducing the number of filters a customer requires to solve both sediment and taste/odor problems into one filter. It is extra important to choose the correct filter when using the same filter for both taste/odor improvement and particulate removal so that the carbon capacity is not wasted by the filter clogging prematurely and vice versa. There are two types of carbon filters - pleated filters impregnated with powdered activated carbon and carbon block filters made out of compressed powdered activated carbon. The life of a carbon block filter can be improved by utilizing a sediment filter with a slightly higher micron rating in front of the carbon block filter - to prevent the carbon filter from becoming clogged prematurely while utilizing both the carbon block filter and sediment filter for particulate capture. Pleated filters impregnated with carbon, such as the PENTEK® C series, offer good particulate filtration efficiency and capacity but very little carbon capacity - often only a few hundred gallons of treated water before the carbon in these filters is exhausted. Siemens recommends carbon block or modified carbon filter block filters over pleated carbon impregnated filters - both because of carbon capacity and resistance to bacterial attack.

PENTEK® EP Series carbon block filters are a basic carbon block with a 5 micron nominal rating. Particles are captured inside a block made of compressed activated carbon so again it is important to consider pretreatment sediment filters in front of a 5 micron carbon block to prevent plugging prematurely. The EPM series of carbon block filters is similar to the EP series instead it is modified to have a larger 10 micron rating to improve resistance to plugging. The PENTEK® CBC and CBR2 series of filters have a 0.5 micron rating and are normally used to reduce (not eliminate) cysts present in water. A filter wtih a 0.5 micron rating naturally has a higher pressure drop and is more succeptible to plugging so pretreatment is recommended if not required. CBC and CBR2 filters are not recommended for point of entry applications, only point of use.

PENTEK® has three newer series of carbon block filters that utilize carbon fiber technology for increased resistance to plugging and lower pressure drops. The CFB and CFB Plus series of modified fiber carbon block filters have micron ratings of 5 or 10 microns are are constructed of powdered activated carbon attached to a cellulose free fiber support. The result is that CFB and CFB Plus filters have about twice the carbon capacity of a normal carbon block filter with even better particulate removal and superior resistance to plugging. Pentek CFBC series modified carbon fiber block filters feature the same Fibredyne™ technology as the CFB series except with a 0.5 micron rating for cyst reduction. The CFB series filter with 0.5 micron filter is a higher capacity/higher resistance to plugging solution to point of use cyst reduction than the traditional CBC series of filter. A better solution for higher flow cyst reduction such as residential point of entry would be the PENTEK® FloPlus series of modified carbon block filter. This 0.5 micron carbon block filter has lower pressure drop ratings and higher flow rates than a traditional 0.5 micron filter - removing cysts and small particles with a pressure drop more like a 10 micron carbon block filter. This performance results in more flow and a longer effective life.

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