INFO – Why Use a Carbon Cabin Filter? with Part Numbers.
09-20-2012, 10:14 PM
#1
Burning Brakes
Thread Starter
INFO – Why Use a Carbon Cabin Filter? with Part Numbers.
A Carbon (activated Charcoal) type combination Cabin Filter not only removes solid particles, it also removes (adsorbs) the gases common in smog and general air pollution, which are harmful to your health.
A combination filter is a compromise between removal of gases, and removal of particles. A combi-filter is less efficient at particle removal than a pure particle filter. Of course, a premium combi-filter may be more efficient at particle removal, than a cheap particle-only filter. The following information will help you to decide which type of filter you wish to purchase.
While there are currently standard tests for comparing Cabin Filter efficiency, from the SAE (USA), the DIN (Germany) and JIS/ JEM (Japan), the results of such tests are not publicly available. And of course, the standards are all different.
I think it would be useful to be able to compare Cabin Filters in the same manner in which we can compare engine oil filters. And I think that it would also be useful to have some minimum defined efficiency standards for Cabin Filters, just as we do for engine oil. But do not hold your breath waiting.
DISCLAIMER: the information provided here for the various Cabin Filters is for reference only. It is the only technical data that I found for any Cabin Filters. I have no connection to or association with any of the brands discussed, other than that I have used micronAir and FRAM filters in my own RDX.
PART NUMBERS for CABIN FILTER for Acura 2009 RDX:
I assume that the same filter fits all years of the RDX, but since I do not know that for certain, check with your parts supplier when purchasing a filter for your own vehicle. BTW, the same filter(s) below will fit most Honda/ Acura models for the past 10 years – but check for your particular model and year.
ACDelco: CF159 ($30)
ATP: CF-40 (standard $10), HA-5 (carbon $22) country-unknown [United Auto Parts]
Autopart International: 5005-29258
Airqualitee: AQ1058
Baldwin: PA4196
Beck/Arnley: 042-2023 ($30)
Bosch: P3875WS (workshop $23), P3875 (premium $30) NOTE 8
Carquest: 89815
Champion: CAF1781 (standard $18) USA, CAF7781 (carbon $15) CHINA
Denso: 453-2026 NOTE 7
FilterMaster: FHN-01001C (carbon $12/ sale $8) country-unknown
Firestone: CAF1781
Fram Fresh Breeze: CF10134 (carbon w/ baking soda $18) CHINA[O'Reilly]
General Motors: 1916-1769
GK Industries: CF1047
Hastings: AF1244
Honda: 80292-SEC-A01 (OEM $40) NOTE 1
.............80292-SDA-A01 (USA $22) NOTE 2
.............80292-SHJ-A41 (fits MDX models $40) NOTE 3
Mahle: LA216 ($17)
Mann: MC1008 ($8)
micronAir: HN03104P (particle $13) USA, HN03104C (carbon $23) USANOTE 4
Mobil: MCAF1781
NAPA: 4815 (WIX manufacturer?)
Omega: 98-01040
Pentius: PHB5519 ($7)
Pronto: PC5519 ($5)
Purolator: C35519 (particle $15) USA[PepBoys] NOTE 5
QuakerState: PV-58
Shell: C35519P
STP: CAF1781 (standard $18) USA, CAF7781 (carbon $15) CHINA[AutoZone]
TYC: 800016P ($6)
Valvoline: C35519P
Warner: WCAF1781
Wix: 24815 (with BioShield-75 $23) POLANDNOTE 6
NOTE 1 - this is the Acura OEM (OLD) part number for RDX cars, no longer available.
NOTE 2 - this is the supersession (NEW) part number for RDX cars.
NOTE 3 - the RDX and MDX OEM filters are the same physical size, but they are not the same. The MDX filter has fewer and thinner pleats. Neither is a carbon type filter.
NOTE 4 - the micronAir filter replaces both the RDX and MDX OEM filters.
http://www.filters-now.com/selector_multi.php?pid=Auto#skipmenu
NOTE 5 - Purolator does make some Carbon type cabin filters, but not for the RDX. Do not be confused by the filter box, which indicates that the filter has an Activated Carbon layer. If you read the box carefully, there is an asterisked note that states that activated carbon is contained only in a few specific filters, not necessarily the one you are holding in your hand.
NOTE 6 - BioShield-75 kills FLU viruses? read about it here:
http://www.midwestbioshield.com
NOTE 7 - Denso does make some Carbon type cabin filters, but not for the RDX.
http://www.densoaftermarket.com/cabin-air-filter.php
NOTE 8 - Bosch does make some Carbon type cabin filters, but not for the RDX. The same part number with “WS” added means the work-shop version, which is the same exact Premium filter in a plain white box, sold in quantity to repair shops, at a much lower price than the same Premium filter in a fancy box, so that the shop can re-sell it to you (the customer) at a profit.
http://www.boschautoparts.com/VehiclePartFinder/Pages/VehiclePartFinder.aspx
ABOUT THE LIST ABOVE:
The list above is part numbers that I found when looking for a CARBON (activated charcoal) filter for my own RDX. This is by no means a complete list. But there are only a few actual manufacturers. Many different vendors are selling filters from the same one manufacturer, with the same part number. Estimated prices range from $5 to $40, and the quality varies to match. Prices vary depending upon which parts store, or online site (plus shipping of course) from which you make your purchase.
The list above is provided as a help in locating an automotive parts-place to purchase your RDX cabin filter. Most parts-stores only carry specific brands, with limited vehicle coverage.
The list above is what is called a cross-reference parts-list. That means that the micronAir p/n HN03104C replaces both the RDX and MDX Honda OEM cabin filters. And, any single part number on the list is supposed to replace any other part number on the list.
But that does not mean that every filter on the list will actually fit both the RDX and the MDX. You will need to check with the parts person, for the actual part number for your RDX, and verify that it really fits your RDX.
So how can the statements above, which seem contradictory, be true? It is because many of the filters, specifically the micronAir p/n HN03104P, is a close fit for the RDX, but it is definitely not an exact fit for the RDX. The FRAM filter fit my RDX as well as the OEM filter. Check the installation tips at the end of this post.
WHICH CABIN AIR FILTER(s) HAVE I USED?
I replace my cabin filter once per year, or at about 8-10K miles. When I replaced the OEM filter it was so black, that I argued with the Acura parts desk that it must be a carbon type – nope.
I have used two filters by micronAir p/n HN03104C carbon type (activated charcoal). The third filter was a FRAM p/n CF10134 carbon type, because I did not want to wait for the micronAir to be shipped. I had to order the micronAir filters online, and pay shipping the first time. My second order had free shipping because of a summer sale.
micronAir claims to supply 65% of all OEM vehicle cabin filters. This claim, plus the information from their web site, influenced my decision to purchase this brand. And the micronAir carbon filter is not made in China.
Until recently, the RDX cabin filters at my local Acura dealer were either from Japan ($40) or from micronAir ($25). In September 2012 when I checked, the Acura dealer filter was simply marked Made in the USA and Honda, and priced at $21 for a non-carbon type filter.
The micronAir filter for the RDX is about 1/8-inch too short. It must be carefully ‘stretched’ and inserted, to avoid tearing. See the installation instructions at the end of this post. Despite this shortcoming (pun intended), I found the micronAir filters worked very well (subjectively) in extremely dusty desert conditions – and driving down dirt roads.
ABOUT THE micronAir CABIN AIR FILTER DATA:
The information presented here can be used to compare Cabin Filters, if you can find the information for the filter you want to compare.
micronAir is a brand for the Freudenberg Nonwovens Group (in Germany) aka Freudenberg Filtration Technologies (USA branch office), which developed the technology used in micronAir Cabin Air Filters. Note that the information presented here is a summary from the articles published by Freudenberg. But the data in those articles does not necessarily apply directly to the specific micronAir Cabin Filter for the RDX.
The original micronAir articles are available online here, as of September 2012.
LINK TO ARTICLES:http://www.micronair.com/en/automotive/publications/index.php
GASEOUS POLLUTION REMOVAL (ADSORPTION) BY THE micronAir COMBI-FILTER:
Prior to 1992 filter blocks containing up to 900 grams of carbon were used to filter out harmful gases, but the blocks built up too high pressure losses in most HVAC (heating, ventilation, and air-conditioner) systems. The filter blocks were only used in a few very high-end (expensive) vehicles, where a high-output HVAC air-flow system could be provided.
A micronAir combi-filter is a particle filter which includes an additional layer of GAC (granulated activated charcoal), a form of carbon, in the filter medium. Air pollution gas is permanently removed by being adsorbed into the GAC layer. The primary goal of a combi-filter is “peak-shaving” of the pollution gases, by keeping their level below the passenger’s threshold value of perception. Removing all of the harmful gases is impractical. And the GAC layer does reach a saturation point, requiring filter replacement.
The graph below shows the ability of micronAir GAC to remove harmful gases. Note that the graph is logarithmic and not linear. Each 3(dB) reduction in odor level means a 50% reduction in the actual gas concentration. So for the DIESEL EXHAUST GAS a reduction in odor level from 35(dB) to 26(dB) is an actual reduction of 87%. That means a reduction from 100% to 13% of the original gas-concentration.
So although complete removal of dangerous gases does not occur, significant reduction does occur. And if the HVAC system is used in re-circulate mode the reduction is even greater. Furthermore, the particle-filter part of the micronAir combi-filter also removes the Diesel Exhaust Soot particles which contribute to the odor (smell), providing a further reduction in the total odor level.
PICTURE: odor reduction
The gas adsorption capacity of a filter is defined as the mass of the gas adsorbed before 95% breakthrough value of the challenge gas versus time. Breakthrough is when the gas concentration DOWNSTREAM (exit-side) of the filter reaches 95% of the gas concentration UPSTREAM (entry-side) of the filter medium. The gases in the chart below are the typical gases used in the standardized DIN test procedure.
PICTURE: gas-breakthrough
The following graph compares the odor reduction of cigarette smoke between a PHOTO-CATALYTIC AIR PURIFIER and a micronAircombi-filter. As you can see, themicronAircombi-filter compares almost equally well in performance.
PICTURE: cigarette odor removal
WHY A SUBMICRON-PARTICLE HIGHLY EFFICIENT FILTER IS DESIRABLE:
Particles smaller than 2.5 (um=micrometers) can become trapped deep inside the lungs, after inhalation, damaging personal health. Current USA emissions standards, especially those for Diesel powered vehicles, take this into account. Remember the next time you are behind a vehicle exhausting a black cloud, its not just the smell that is toxic.
PICTURE: relative particle sizes
Particles smaller than 1.0 micron can pass the thorax and get into the alveolar tract of the respiratory system. Part of the very fine particles can be exhaled, but 20-30% remain inside the lungs for a long period of time, and can even enter the blood circulation.
Additionally these small particles are known to be a carrier of odors and toxic substances such as heavy metals and polycyclic aromatic hydrocarbons (PAH). As a consequence carcinogenic and inflammatory reactions such as asthma may arise.
PICTURE: areas of particle deposition
AS A SIDE NOTE: today 18 Sep 2012 there was a broadcast article on NPR (national public radio) where I live, possibly linking PAH to childhood obesity (along with BPA in plastic food packaging), so far unconfirmed. It is certainly not the first time that air pollution has been (possibly) linked to various childhood health problems.
micronAir Cabin Filter PARTICLE REMOVAL EFFICIENCY
The following diagram shows what was stated above, that most particles <1.0 microns cannot be exhaled, once they have been inhaled. So an efficient particle filter, that removes these particles, is very important.
A micronAir particle filter-medium can remove a large part of about 70-80% of submicron particles, thus significantly improving comfort and health protection in the car interior.
PICTURE: particle deposition probability
PUROLATOR Cabin Filter PARTICLE REMOVAL EFFICIENCY
The packaging for the Purolator C35519 filter states that the filter is “up to 95% efficient”, but does not state at what particle size this rating is given.
WHAT KIND OF PARTICLES ARE WE TALKING ABOUT? Abraded particles are often the result of studded snow tires, comprised of both the road surface and the studs themselves. Neither are something that you want to be breathing.
PICTURE: particle types by size
PARTICLE FILTER vs. COMBI-FILTER COLLECTION EFFICIENCY:
I do not know which is more harmful health-wise, pollution gases or particles. But I do know that both pollution gases and particles are harmful to health.
Activated charcoal in combination with a particle filter medium, which is highly efficient in the submicron particle range, allows a filter medium to be designed which is especially suited to meet the requirements of a <2.5 micron particle pollution environment.
Particle efficiency values for combination filters are lower than the efficiency values for pure-particle filters. The limited power output of the HVAC blower leads to a maximum acceptable filter pressure drop. The pressure drop of a combi-filter consists of the pressure drop of the particle filter material, plus the pressure drop of the activated carbon layer.
To keep the overall pressure drop of a combi-filter to a reasonable level, the particle filter material has a lower particle filtering efficiency. Additionally, the filter area in a combi-filter is lower because of the additional carbon layer, which leads to a higher thickness of the whole filter material. That requires that the pleat pitch spacing is wider. The reduction in filtering area (20-40%) leads to a higher filtration velocity through the filter material, and thus to a reduced fractional particle-collection efficiency.
Therefore, combination filters show a higher initial pressure loss, and lower dust holding capacity compared to particle filters with identical geometry (size). That means a combi-filter should be replaced more often. Just check it often and change when it is dirty.
PICTURE: particle vs. combi-filter collection efficiency
Do note that a quality combi-filter may be much more efficient (at particle removal) than a cheap pure particle filter.
ALTERNATIVES TO ACTIVATED CARBON:
The WIX Cabin Filter uses BioShield-75 to kill viruses that pass through the filter. This ability might be useful in a vehicle used for car-pooling to help prevent spread of FLU and other viruses among the passengers. Obviously, the BioShield-75 would be most effective in HVAC re-circulate mode. This filter does not contain carbon, do it does not offer gas odor reduction. I could find no information concerning particle filtering efficiency for the WIX Cabin Filter.
Information concerning the BioShield-75 product is available here. Note that WIX does not provide any technical information on this product, as used in their filters:
LINK TO BIOSHIELD-75: http://www.midwestbioshield.com
The FRAM Cabin Filter for the RDX contains baking-soda in addition to GAC (granulated activated charcoal). The packaging says that the baking-soda is there to adsorb odors. I use an opened package of baking-soda inside my refrigerator to help control odors – it works.
However, I have to wonder if baking-soda works better than, or even as well as, GAC? Or if maybe baking-soda is being used in the FRAM filter because it is a lot cheaper than GAC? I have no problem that baking-soda is cheaper than activated carbon. But is it as effective? Without the results of standardized tests, we have no way of knowing.
HOW TO CHANGE THE CABIN-FILTER:
There is an excellent post describing how to change the Cabin Filter in your RDX, here:
LINK TO FILTER CHANGE: https://acurazine.com/forums/showthread.php?t=681583
PROPER INSTALLATION OF THE CABIN-FILTER:
I previously posted the following in another thread, but am reposting it here because it has become ‘buried’ in the other thread.
I was not paying attention when I removed the OLD filter from the cabin filter container. So I did not notice immediately, that to properly seal the ends of the filter, the pleat on each end of the filter must be inserted between the end of the container and the tab on each end of the contain, as in this picture below from the FSM (factory service manual).
Also, I find it much easier to install the container ‘over’ the filter. Flip the filter upside down, note the directional air-flow arrows on the filter and the container, and place the container down over the filter. Then I can easily see that the end tabs on the container are placed correctly.
PICTURE: cabin filter installation
PICTURE: cabin filter DETAIL
As the driver of this RDX is very sensitive to pollen and air pollution, I also wanted a good seal on the sides and corners of the filter, into the filter container.
Apply a thin bead of Silicone Seal along each side of the container, and a small ‘blob’ in the corners, before installing the filter. DO NOT use regular silicone sealer, as it will stick to the plastic container so well that it will be almost impossible to remove.
Instead, use Permatex brand Ultra-Grey Sensor Safe Gasket Maker. It dries to a much firmer consistency than regular silicone sealer, and does not stick as well to plastic. To remove the filter, just push firmly against the filter, and the Ultra-Grey will ‘pop’ loose from the container, leaving a clean surface on the container.
Another brand or type of sealer may also work, but I am only certain of the Permatex brand stuff, as described above.
PICTURE: cabin filter SEALER
-------eof
A combination filter is a compromise between removal of gases, and removal of particles. A combi-filter is less efficient at particle removal than a pure particle filter. Of course, a premium combi-filter may be more efficient at particle removal, than a cheap particle-only filter. The following information will help you to decide which type of filter you wish to purchase.
While there are currently standard tests for comparing Cabin Filter efficiency, from the SAE (USA), the DIN (Germany) and JIS/ JEM (Japan), the results of such tests are not publicly available. And of course, the standards are all different.
I think it would be useful to be able to compare Cabin Filters in the same manner in which we can compare engine oil filters. And I think that it would also be useful to have some minimum defined efficiency standards for Cabin Filters, just as we do for engine oil. But do not hold your breath waiting.
DISCLAIMER: the information provided here for the various Cabin Filters is for reference only. It is the only technical data that I found for any Cabin Filters. I have no connection to or association with any of the brands discussed, other than that I have used micronAir and FRAM filters in my own RDX.
PART NUMBERS for CABIN FILTER for Acura 2009 RDX:
I assume that the same filter fits all years of the RDX, but since I do not know that for certain, check with your parts supplier when purchasing a filter for your own vehicle. BTW, the same filter(s) below will fit most Honda/ Acura models for the past 10 years – but check for your particular model and year.
ACDelco: CF159 ($30)
ATP: CF-40 (standard $10), HA-5 (carbon $22) country-unknown [United Auto Parts]
Autopart International: 5005-29258
Airqualitee: AQ1058
Baldwin: PA4196
Beck/Arnley: 042-2023 ($30)
Bosch: P3875WS (workshop $23), P3875 (premium $30) NOTE 8
Carquest: 89815
Champion: CAF1781 (standard $18) USA, CAF7781 (carbon $15) CHINA
Denso: 453-2026 NOTE 7
FilterMaster: FHN-01001C (carbon $12/ sale $8) country-unknown
Firestone: CAF1781
Fram Fresh Breeze: CF10134 (carbon w/ baking soda $18) CHINA[O'Reilly]
General Motors: 1916-1769
GK Industries: CF1047
Hastings: AF1244
Honda: 80292-SEC-A01 (OEM $40) NOTE 1
.............80292-SDA-A01 (USA $22) NOTE 2
.............80292-SHJ-A41 (fits MDX models $40) NOTE 3
Mahle: LA216 ($17)
Mann: MC1008 ($8)
micronAir: HN03104P (particle $13) USA, HN03104C (carbon $23) USANOTE 4
Mobil: MCAF1781
NAPA: 4815 (WIX manufacturer?)
Omega: 98-01040
Pentius: PHB5519 ($7)
Pronto: PC5519 ($5)
Purolator: C35519 (particle $15) USA[PepBoys] NOTE 5
QuakerState: PV-58
Shell: C35519P
STP: CAF1781 (standard $18) USA, CAF7781 (carbon $15) CHINA[AutoZone]
TYC: 800016P ($6)
Valvoline: C35519P
Warner: WCAF1781
Wix: 24815 (with BioShield-75 $23) POLANDNOTE 6
NOTE 1 - this is the Acura OEM (OLD) part number for RDX cars, no longer available.
NOTE 2 - this is the supersession (NEW) part number for RDX cars.
NOTE 3 - the RDX and MDX OEM filters are the same physical size, but they are not the same. The MDX filter has fewer and thinner pleats. Neither is a carbon type filter.
NOTE 4 - the micronAir filter replaces both the RDX and MDX OEM filters.
http://www.filters-now.com/selector_multi.php?pid=Auto#skipmenu
NOTE 5 - Purolator does make some Carbon type cabin filters, but not for the RDX. Do not be confused by the filter box, which indicates that the filter has an Activated Carbon layer. If you read the box carefully, there is an asterisked note that states that activated carbon is contained only in a few specific filters, not necessarily the one you are holding in your hand.
NOTE 6 - BioShield-75 kills FLU viruses? read about it here:
http://www.midwestbioshield.com
NOTE 7 - Denso does make some Carbon type cabin filters, but not for the RDX.
http://www.densoaftermarket.com/cabin-air-filter.php
NOTE 8 - Bosch does make some Carbon type cabin filters, but not for the RDX. The same part number with “WS” added means the work-shop version, which is the same exact Premium filter in a plain white box, sold in quantity to repair shops, at a much lower price than the same Premium filter in a fancy box, so that the shop can re-sell it to you (the customer) at a profit.
http://www.boschautoparts.com/VehiclePartFinder/Pages/VehiclePartFinder.aspx
ABOUT THE LIST ABOVE:
The list above is part numbers that I found when looking for a CARBON (activated charcoal) filter for my own RDX. This is by no means a complete list. But there are only a few actual manufacturers. Many different vendors are selling filters from the same one manufacturer, with the same part number. Estimated prices range from $5 to $40, and the quality varies to match. Prices vary depending upon which parts store, or online site (plus shipping of course) from which you make your purchase.
The list above is provided as a help in locating an automotive parts-place to purchase your RDX cabin filter. Most parts-stores only carry specific brands, with limited vehicle coverage.
The list above is what is called a cross-reference parts-list. That means that the micronAir p/n HN03104C replaces both the RDX and MDX Honda OEM cabin filters. And, any single part number on the list is supposed to replace any other part number on the list.
But that does not mean that every filter on the list will actually fit both the RDX and the MDX. You will need to check with the parts person, for the actual part number for your RDX, and verify that it really fits your RDX.
So how can the statements above, which seem contradictory, be true? It is because many of the filters, specifically the micronAir p/n HN03104P, is a close fit for the RDX, but it is definitely not an exact fit for the RDX. The FRAM filter fit my RDX as well as the OEM filter. Check the installation tips at the end of this post.
WHICH CABIN AIR FILTER(s) HAVE I USED?
I replace my cabin filter once per year, or at about 8-10K miles. When I replaced the OEM filter it was so black, that I argued with the Acura parts desk that it must be a carbon type – nope.
I have used two filters by micronAir p/n HN03104C carbon type (activated charcoal). The third filter was a FRAM p/n CF10134 carbon type, because I did not want to wait for the micronAir to be shipped. I had to order the micronAir filters online, and pay shipping the first time. My second order had free shipping because of a summer sale.
micronAir claims to supply 65% of all OEM vehicle cabin filters. This claim, plus the information from their web site, influenced my decision to purchase this brand. And the micronAir carbon filter is not made in China.
Until recently, the RDX cabin filters at my local Acura dealer were either from Japan ($40) or from micronAir ($25). In September 2012 when I checked, the Acura dealer filter was simply marked Made in the USA and Honda, and priced at $21 for a non-carbon type filter.
The micronAir filter for the RDX is about 1/8-inch too short. It must be carefully ‘stretched’ and inserted, to avoid tearing. See the installation instructions at the end of this post. Despite this shortcoming (pun intended), I found the micronAir filters worked very well (subjectively) in extremely dusty desert conditions – and driving down dirt roads.
ABOUT THE micronAir CABIN AIR FILTER DATA:
The information presented here can be used to compare Cabin Filters, if you can find the information for the filter you want to compare.
micronAir is a brand for the Freudenberg Nonwovens Group (in Germany) aka Freudenberg Filtration Technologies (USA branch office), which developed the technology used in micronAir Cabin Air Filters. Note that the information presented here is a summary from the articles published by Freudenberg. But the data in those articles does not necessarily apply directly to the specific micronAir Cabin Filter for the RDX.
The original micronAir articles are available online here, as of September 2012.
LINK TO ARTICLES:http://www.micronair.com/en/automotive/publications/index.php
GASEOUS POLLUTION REMOVAL (ADSORPTION) BY THE micronAir COMBI-FILTER:
Prior to 1992 filter blocks containing up to 900 grams of carbon were used to filter out harmful gases, but the blocks built up too high pressure losses in most HVAC (heating, ventilation, and air-conditioner) systems. The filter blocks were only used in a few very high-end (expensive) vehicles, where a high-output HVAC air-flow system could be provided.
A micronAir combi-filter is a particle filter which includes an additional layer of GAC (granulated activated charcoal), a form of carbon, in the filter medium. Air pollution gas is permanently removed by being adsorbed into the GAC layer. The primary goal of a combi-filter is “peak-shaving” of the pollution gases, by keeping their level below the passenger’s threshold value of perception. Removing all of the harmful gases is impractical. And the GAC layer does reach a saturation point, requiring filter replacement.
The graph below shows the ability of micronAir GAC to remove harmful gases. Note that the graph is logarithmic and not linear. Each 3(dB) reduction in odor level means a 50% reduction in the actual gas concentration. So for the DIESEL EXHAUST GAS a reduction in odor level from 35(dB) to 26(dB) is an actual reduction of 87%. That means a reduction from 100% to 13% of the original gas-concentration.
So although complete removal of dangerous gases does not occur, significant reduction does occur. And if the HVAC system is used in re-circulate mode the reduction is even greater. Furthermore, the particle-filter part of the micronAir combi-filter also removes the Diesel Exhaust Soot particles which contribute to the odor (smell), providing a further reduction in the total odor level.
PICTURE: odor reduction
The gas adsorption capacity of a filter is defined as the mass of the gas adsorbed before 95% breakthrough value of the challenge gas versus time. Breakthrough is when the gas concentration DOWNSTREAM (exit-side) of the filter reaches 95% of the gas concentration UPSTREAM (entry-side) of the filter medium. The gases in the chart below are the typical gases used in the standardized DIN test procedure.
PICTURE: gas-breakthrough
The following graph compares the odor reduction of cigarette smoke between a PHOTO-CATALYTIC AIR PURIFIER and a micronAircombi-filter. As you can see, themicronAircombi-filter compares almost equally well in performance.
PICTURE: cigarette odor removal
WHY A SUBMICRON-PARTICLE HIGHLY EFFICIENT FILTER IS DESIRABLE:
Particles smaller than 2.5 (um=micrometers) can become trapped deep inside the lungs, after inhalation, damaging personal health. Current USA emissions standards, especially those for Diesel powered vehicles, take this into account. Remember the next time you are behind a vehicle exhausting a black cloud, its not just the smell that is toxic.
PICTURE: relative particle sizes
Particles smaller than 1.0 micron can pass the thorax and get into the alveolar tract of the respiratory system. Part of the very fine particles can be exhaled, but 20-30% remain inside the lungs for a long period of time, and can even enter the blood circulation.
Additionally these small particles are known to be a carrier of odors and toxic substances such as heavy metals and polycyclic aromatic hydrocarbons (PAH). As a consequence carcinogenic and inflammatory reactions such as asthma may arise.
PICTURE: areas of particle deposition
AS A SIDE NOTE: today 18 Sep 2012 there was a broadcast article on NPR (national public radio) where I live, possibly linking PAH to childhood obesity (along with BPA in plastic food packaging), so far unconfirmed. It is certainly not the first time that air pollution has been (possibly) linked to various childhood health problems.
micronAir Cabin Filter PARTICLE REMOVAL EFFICIENCY
The following diagram shows what was stated above, that most particles <1.0 microns cannot be exhaled, once they have been inhaled. So an efficient particle filter, that removes these particles, is very important.
A micronAir particle filter-medium can remove a large part of about 70-80% of submicron particles, thus significantly improving comfort and health protection in the car interior.
PICTURE: particle deposition probability
PUROLATOR Cabin Filter PARTICLE REMOVAL EFFICIENCY
The packaging for the Purolator C35519 filter states that the filter is “up to 95% efficient”, but does not state at what particle size this rating is given.
WHAT KIND OF PARTICLES ARE WE TALKING ABOUT? Abraded particles are often the result of studded snow tires, comprised of both the road surface and the studs themselves. Neither are something that you want to be breathing.
PICTURE: particle types by size
PARTICLE FILTER vs. COMBI-FILTER COLLECTION EFFICIENCY:
I do not know which is more harmful health-wise, pollution gases or particles. But I do know that both pollution gases and particles are harmful to health.
Activated charcoal in combination with a particle filter medium, which is highly efficient in the submicron particle range, allows a filter medium to be designed which is especially suited to meet the requirements of a <2.5 micron particle pollution environment.
Particle efficiency values for combination filters are lower than the efficiency values for pure-particle filters. The limited power output of the HVAC blower leads to a maximum acceptable filter pressure drop. The pressure drop of a combi-filter consists of the pressure drop of the particle filter material, plus the pressure drop of the activated carbon layer.
To keep the overall pressure drop of a combi-filter to a reasonable level, the particle filter material has a lower particle filtering efficiency. Additionally, the filter area in a combi-filter is lower because of the additional carbon layer, which leads to a higher thickness of the whole filter material. That requires that the pleat pitch spacing is wider. The reduction in filtering area (20-40%) leads to a higher filtration velocity through the filter material, and thus to a reduced fractional particle-collection efficiency.
Therefore, combination filters show a higher initial pressure loss, and lower dust holding capacity compared to particle filters with identical geometry (size). That means a combi-filter should be replaced more often. Just check it often and change when it is dirty.
PICTURE: particle vs. combi-filter collection efficiency
Do note that a quality combi-filter may be much more efficient (at particle removal) than a cheap pure particle filter.
ALTERNATIVES TO ACTIVATED CARBON:
The WIX Cabin Filter uses BioShield-75 to kill viruses that pass through the filter. This ability might be useful in a vehicle used for car-pooling to help prevent spread of FLU and other viruses among the passengers. Obviously, the BioShield-75 would be most effective in HVAC re-circulate mode. This filter does not contain carbon, do it does not offer gas odor reduction. I could find no information concerning particle filtering efficiency for the WIX Cabin Filter.
Information concerning the BioShield-75 product is available here. Note that WIX does not provide any technical information on this product, as used in their filters:
LINK TO BIOSHIELD-75: http://www.midwestbioshield.com
The FRAM Cabin Filter for the RDX contains baking-soda in addition to GAC (granulated activated charcoal). The packaging says that the baking-soda is there to adsorb odors. I use an opened package of baking-soda inside my refrigerator to help control odors – it works.
However, I have to wonder if baking-soda works better than, or even as well as, GAC? Or if maybe baking-soda is being used in the FRAM filter because it is a lot cheaper than GAC? I have no problem that baking-soda is cheaper than activated carbon. But is it as effective? Without the results of standardized tests, we have no way of knowing.
HOW TO CHANGE THE CABIN-FILTER:
There is an excellent post describing how to change the Cabin Filter in your RDX, here:
LINK TO FILTER CHANGE: https://acurazine.com/forums/showthread.php?t=681583
PROPER INSTALLATION OF THE CABIN-FILTER:
I previously posted the following in another thread, but am reposting it here because it has become ‘buried’ in the other thread.
I was not paying attention when I removed the OLD filter from the cabin filter container. So I did not notice immediately, that to properly seal the ends of the filter, the pleat on each end of the filter must be inserted between the end of the container and the tab on each end of the contain, as in this picture below from the FSM (factory service manual).
Also, I find it much easier to install the container ‘over’ the filter. Flip the filter upside down, note the directional air-flow arrows on the filter and the container, and place the container down over the filter. Then I can easily see that the end tabs on the container are placed correctly.
PICTURE: cabin filter installation
PICTURE: cabin filter DETAIL
As the driver of this RDX is very sensitive to pollen and air pollution, I also wanted a good seal on the sides and corners of the filter, into the filter container.
Apply a thin bead of Silicone Seal along each side of the container, and a small ‘blob’ in the corners, before installing the filter. DO NOT use regular silicone sealer, as it will stick to the plastic container so well that it will be almost impossible to remove.
Instead, use Permatex brand Ultra-Grey Sensor Safe Gasket Maker. It dries to a much firmer consistency than regular silicone sealer, and does not stick as well to plastic. To remove the filter, just push firmly against the filter, and the Ultra-Grey will ‘pop’ loose from the container, leaving a clean surface on the container.
Another brand or type of sealer may also work, but I am only certain of the Permatex brand stuff, as described above.
PICTURE: cabin filter SEALER
-------eof
Last edited by dcmodels; 09-20-2012 at 10:18 PM.
The following 2 users liked this post by dcmodels:
gertab (09-17-2014),
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