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  1. #1
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    IAQ Fundamentals, VOCs, MoleKule/Carbon Testing

    About a year ago I posted results of VOC testing using the MoleKule and the Austin Air HP+ on HVAC-Talk.
    Due to a server crash all posts were lost. At the same time I was working with MoleKule on a second round of testing.
    I posted a primer on Reddit with a promise to post the latest results to follow. Apologizes for the delay in posting part 2. A number of folks have requested this update both privately and on Redit and HVAC-Talk over the last few months.

    This post is intended to stand on its own but part 1 can be found at
    https://www.reddit.com/r/molekule/co...ekule_testi_1/

    I'm not an Indoor Air Quality (IAQ) professional but I do work in the basic science and engineering fields.
    In 2015 I purchased a condo that had serious, elevated VOC issues. After months of floundering and
    taking the advice of *professionals* and non-professionals that should have known better, I decided
    to take matters in my own hands. I'm going to provide a brief summary of IAQ issues specifically
    concerning VOCs to establish a basic understanding.
    Hopefully folks that know more can correct, add to, or expand. I'm fond of academic references
    and objective research so I'll provide links for folks a deeper look.

    I hope folks take the time to read the overview. A lot of misunderstanding abounds and the more
    we know the better we can challenge manufacturers and resellers.
    I suspect that some of the folks selling these devices donít know near what they think they know.
    A good story is easy to believe and retell. The same stories are repeated and myths are propagated.
    Here are some resources that offer extended evidence based discussions on all things IAQ:

    http://www.iaqa.org/ - Superb resource for everything IAQ including professional online courses
    http://indoorairnerd.com/ -

    Lawrence Berkeley National Laboratory probably has the largest collections of PHDs actively
    involved in IAQ science and research. They provide a lot of information for the public on all things IAQ
    https://iaqscience.lbl.gov/

    The EPA has tons of useful information:
    https://www.epa.gov/sites/production...ng_devices.pdf
    https://www.epa.gov/indoor-air-quali...anic-compounds
    https://www.epa.gov/indoor-air-quality-iaq

    Components of IAQ:
    Two major components of IAQ are (1) particulates and (2) VOCs. There are other components
    (biologicals-a particulate, radon, CO2, CO, SVOCs, Ozone, Nitrogen and Sulfur compounds and other stuff)
    but in my situation and I suspect many others (urban North American primarily)
    particulates and VOCs are the major offenders.

    Hereís a good overview of all the components of IAQ:
    https://buildingscience.com/sites/de...ett_singer.pdf

    Particulates
    Particulates are objects as small as .001 microns (1micron = 1/millionth of a meter).
    This can include both inert and biological (viruses, bacteria, tiny bugs, mold, ect, ) components.
    Smaller objects are generally more troublesome for a number of reasons.
    This pollution is often referred as PM 2.5 - meaning particles <= 2.5 microns.
    Fortunately particulate matter can be easily handled (in indoor urban environments) with HEPA filtration.
    For a good overview of residential HEPA devices and particulate issues see:

    1. https://thewirecutter.com/reviews/best-air-purifier/

    2. https://smartairfilters.com/cn/en/
    Great site. Great work. Highly recommend for anything about particulates (not VOCs).
    Itís worth taking the time exploring what these folks have done.
    My hats off Thomas Talhelm and his associates in Asia. This is capitalism at its best.

    3. https://www.engineeringtoolbox.com/p...zes-d_934.html
    Great reference for the sizes of various particulates. Fascinating!

    A true HEPA filter will trap particles down to .01micron. I use to think the .3microns was
    the smallest particle that could be caught by HEPAs, not so.
    A .3micron particle is the most difficult particle to trap, not the smallest.
    Most folks, even ones that sell HEPA filters are not aware of this.
    A good HEPA filter is an amazing device and eliminate of a lot of very small stuff floating in the air.
    BUT Ė VOCs are not trapped by HEPA filters

    To measure Particulate Levels I use the Dylos meter. Industrial particulate meters are also available,
    but the Dylos, imo, provides a very good value. Some of the new batch of MOS semiconductor meters are
    rumored to be useful for particulate measurements but I have no experience with these.

    What are VOCs:
    VOC are organic hydro-carbons in various configurations. Some are established carcinogens
    (benzene /formaldehyde and others) and many have established negative biological effects

    https://iaqscience.lbl.gov/voc-cancer

    How are VOCs quantified:
    VOCs can be specified in Parts per Billion (ppb/ppm). Basically take a billion particle sample and count
    the VOCs. For instance, if you grab a billion particles from your living room air and determine that
    100 of them are formaldehyde you have 100ppb of formaldehyde. .

    Another commonly used method is to weight the VOCs in one liter of air. If the VOCs weigh over
    400 ng/liter (billionths of a gram) concentrations are higher than recommended.
    The higher the number the worse the issue. Iíve had readings over 2500ng/liter.
    My impression is that many residences are much higher than suspected.

    Note: Often time VOCs are denominated as ug/m^3. This is equivalent to ng/liter.

    What instruments are used to measure VOCs?
    1. PID (photoionization) meters. These devices can provide a rough estimate of Total VOC Levels (TVOC).
    This can be very useful in taking relative readings. This is what I used when testing the
    MoleKule. Take a measurement before and after turning on the MoleKule. The absolute readings are not
    always accurate or that useful but the relative readings will indicate if a device is having an effect.
    These devices will almost always underestimate the true TVOC level due to technical limitations.
    Also note only TVOC (total) levels can be determined. PID meters cannot indicate what
    the individual components of the VOCs are.
    Still this device is invaluable in determining if VOCs are raised and how well remediation techniques are working. For more information see: https://en.wikipedia.org/wiki/Photoionization_detector

    Please note that PID meters come in two flavors ppb and ppm. Only ppb devices should be used in residences.
    PPM versions do not have the resolution to provide useful data.

    I used the ppbRae3000 that I rented from Pine Environmental. Pine Environmental has about many rental outlets in the US.
    http://www.pine-environmental.com/locations/

    The folks at Pine aim to please and they have assisted in resolving a number of issues I encountered along the way.

    If you do rent one of these devices you should verify proper calibration. Send me a PM for details

    3. Gas Chromatography/ Mass Spectrometry. This is the gold standard for testing for VOCs. Not only
    can accurate TVOC levels be measured but the individual VOC components can be determined.
    This process is not difficult. The company providing the analysis sends a sample kit to the end user.
    Simple instructions are provided and a sample is returned to the testing lab.
    Results are available in about 1 week. Both TVOC levels and individual breakdown of VOCs are provided.
    For folks that have a concern I highly recommend using this process at least twice.

    Iíve used these two companies:
    1. https://homeaircheck.com/products/ Least Expensive.
    2.https://www.fikeanalytical.com/ High Quality, recommended

    4. Passive technology. This may be the best method for measuring formaldehyde and some other VOCs.
    The sample is collected on a passive badge and then analyzed by GC.
    https://www.assaytech.com/

    5. MOS technology. This semiconductor technology is being sold in a number of low cost units as
    VOC detectors. From what Iíve seen, the first generation of these devices are not useful.
    Some newer chips are available that show promise. If this approach can be verified
    it will be a big boon to the home user. PID meters and Gas Chromatography can be expensive.
    If home users have a inexpensive way to test their environments, manufactures will be forced to answer why their devices are ineffective.

    An important underappreciated fact about VOCs.
    VOCs boil from 120^F to 500^F. Just like taking a hot shower where water molecules *off gas*
    when the water is nowhere is near 212^F, VOCs off gas from liquids/solids on the surfaces in your home
    Ė that includes walls, floors, plates forks, spoons , ect. If youíve got a VOC problem
    youíre not only inhaling them but rubbing them on your skin and swallowing them.
    VOCs in the air indicate VOCs on your surfaces. Kind of scary.

    Cooler temperatures might reduce odors, but that does not eliminate VOCs. They just condense on your surfaces. An 18^F increase in temperature will double off gassing. If want to shuffle VOC from you living space heat things up and ventilate. This is technique, called a *bake out*, has been studied and verified. See:
    https://www.google.com/search?q=bake...hrome&ie=UTF-8

    VOC abatement:
    Remove the source(s)

    Ventilate:

    Iíve brought down excess readings on a PID meter to close to zero in minutes by
    opening windows/doors and moving air with fans through my condo in a 10 minutes.
    The power of ventilation is amazing. Of course they come up (slower) when everything is buttoned up again.

    Depending on where you live and time of year this may not be practical due to humidity and temperature concerns

    I suspect that installing a mechanical ventilation system like an Ultra-Aire or a ERV/HRV system
    would have a huge effect. This is probably the fastest way to treat high VOC levels.
    Not the cheapest way or the most efficient. Fresh air is probably the only cure for non-VOCs such as CO2

    Adsorption:
    These systems sequester the VOCs. Carbon is most commonly used but there are other materials.
    These can be incredibly effective. The latest system I worked with is advertised for marijuana growers.
    Iíve seen reductions of over 60% in minutes measured with the PID meter. Keep in mind Iím
    feeding the PID meter directly out of the exhaust the fan on the carbon canister so it will take a bit longer to filter the air in the room. Hereís the setup I used:

    Itís not pretty and itís loud but the results have been impressive
    https://tinyurl.com/yalkdpek
    https://tinyurl.com/ycfo3x23

    The Austin Air device I used previously was impressive at a 25 -30% reduction
    but the Terrabloom device was over 2x better at 1/3 the cost.
    Keep in mind I donít know how long the Terrabloom device will take to saturate and only activated carbon is used.
    Also some folks have noticed a slight odor.

    The Austin device has a chemosorptive additive that can permanently trap/degrade some VOCs. There is no additive in the Terrabloom device.

    Carbon devices have issues:
    1. They will eventually saturate and then can release previously sequestered VOCs Ė not good
    2. Carbon is picky Ė Some VOCs are preferred over others. Chemical additives are needed if you wish to trap a wider range of VOCs
    3. When temperatures are just moderately increased carbon can desaturate and release previously trapped VOCs
    4. Carbon doesnít work well at higher humidity levels.
    5. Beware of any device that has less than 5lbs of carbon. Some manufactures add thin carbon filter
    to their HEPA devices and claim odor reduction. Be skeptical.
    `
    Photo Catalytic Oxidation (PCO):
    This is the technology that MoleKule and a number of other companies (RGF, AirOsais) use.
    High energy photons irradiate a special catalyst material to produce *Oxidizing agents*.
    These oxidizing agents (hydroxyls,and other stuff) break the hydrogen/carbons bonds of
    VOCs leaving only water and CO2. Of course thatís a best case scenario.
    Itís much messier in the real world with partial and incomplete break down products.
    Sometimes these breakdown products are worse than the original VOCs.
    Some studies have shown increases in formaldehyde, one of the nastier VOCs, as a byproduct of these machines.

    Nevertheless, this technology does work and results have been published in hundreds if not thousands of
    scientific papers since the 70s. NASA used PCO to deal with increased ethylene produced by the
    vegetable gardens in the space shuttle.

    Hereís a good, if simplified, discussion of this technology:
    http://www.explainthatstuff.com/how-...iers-work.html

    Itís interesting to note that the PCO technology discussed in the scientific literature often
    differs from the devices sold in the residential markets. Many of these devices produce hydrogen peroxide
    that is spewed into the living area. Advantages claimed are that this approach can treat surfaces.
    Maybe but Iíve not seen much proof other than the claims of the manufacturers.

    To theirr credit, the MoleKule stays true to the classic PCO where all the action happens at the catalyst.

    Most of the literature shows PCO technology is effective at VERY high VOC concentrations at the ppm level.
    This is much higher than what is typically found in a home. There is not much evidence that PCO is effective at the lower VOCs levels that we are likely to run into.

    Hereís a very good recent overview of PCO technology Ė Highly recommended:
    https://www.mdpi.com/1420-3049/21/1/56/htm

    Non Thermal Plasma (NTP)
    This approach uses strong electric fields to produce the same kind of oxidants as
    PCO but without the UV light. There are hundreds of scientific papers showing this approach works.
    I intend to do some testing with these devices. Most of the discussion in the literature refer to
    Dielectric Barrier Discharge tubes to produce strong electrical fields.
    At least two companies use this technology for residences

    Plasma Air https://plasma-air.com/
    AtMosAir http://atmosair.com/
    Both these devices look promising and I hope to test soon.

    Itís also claimed that this technology will cause smaller particles (VOC?) to attract and
    clump together. These larger particles, itís claimed, are heavier and will fall to the floor
    or be more likely to be collected in a HEPA filter. Even so you will need to vacuum
    often and keep your HEPA running to trap these larger particles. And even if VOC can be
    trapped in this manner they are not destroyed and can possibly vaporize again.
    Still this is fascinating, but I havenít been able to find much confirming evidence.
    If this is true then NTP devices might have a significant advantage. They can reduces VOCs
    with oxidizing agents and additional by clumping them together with particulates via ion attraction.

    Global Plasma Solutions manufactures a device that claims to produce NTP using needle point
    technology. A lot of folks rave about these products but there is not much in the science literature
    using this approach. The supporting data that GPS provides on their web site is not clear.
    They have info on clearing smoke (particulates not VOCs) from a tiny containers or stopping bread from rotting.
    Both impressive demos but these have nothing to do with VOCs.
    I look forward to testing GPS products or at least reading about VOC testing using this device Ėeven if its GPS own testing.

    Biologicals vs VOCs
    Itís much easier to kill a biological than to degrade a VOC. Breaking a few carbon/hydrogen
    bonds in a biological can be enough to kill it, but All carbon/hydrogen bonds in a VOC
    must be broken to degrade it. Otherwise youíre just left with more VOCs than you started with.
    Ergo Ė NTP and PCO devices *might* be very effective for killing biologicals but not so much for for degradingVOCs.

    Some notes about the MoleKule device:
    1.MoleKule is a variant of PCO called PECO. This is a valid, patented technology developed by real academic scientists.
    Hereís a Wikipedia discussion:
    https://en.wikipedia.org/wiki/Photoe...ical_oxidation

    The claim is that PECO produces more oxidizing agents than standard PCO.

    2.The device produces No ozone. Most PCO device produce ozone. Whatís wrong with ozone:
    https://cfpub.epa.gov/airnow/index.c...oduphigh.index

    3.The device uses UVA photons as opposed to UVC. UVA LEDs can be used instead of UVC bulbs.
    This means a much longer life span. No need to replace bulbs every year or so.
    Not to mention decreasing performance as the bulbs wear out.

    4.MoleKule contracted a professional 3rd party testing and provided all the details.
    Unfortunately their testing for VOCs does not relate to real world residences.
    See this post on Reddit for details:
    https://www.reddit.com/r/molekule/co...voc_reduction/
    In short reducing an extremely high concentration of single VOC in a small container to much lower
    but still elevated levels does not mimic the environment in our homes

    5.My interactions with the folks at MoleKule have been stellar Ėway beyond the best that I
    ever expected. I wonít go into details but the engineers and scientists at MoleKule have
    devoted significant time and material in attempting to resolve my issues.
    These guys are real scientiest that publish in scientific journals.

    Testing
    I tested 3 devices, two carbon units and the MoleKule using the ppbRAE3000 that I rented
    from Pine Environmental. I was confident that the ppbRAE3000 was reliable for relative readings.
    I positioned the ppbRAe directly in the exhaust of the carbon and MoleKule units. I tested both side by side
    in a number of different locations. I let the MoleKule run for days in different rooms before testing. I also let the MoleKule run for up to 24 hours between test.

    Results:
    Austin Air HP+ - Measured a 20 Ė 30 percent decrease within minutes
    TerraBloom Ė Measured a 60 Ė 70 percent decrease within minutes
    MoleKule Ė Never measured any significant reduction under a host of testing conditions

    Could I be doing something wrong? Absolutely but for the life of me I can figure out what.
    Perhaps the MoleKule needs to run for days or weeks for significant reduction. If thatís true MoleKule should say so.

    Recently MoleKule announced that they have new 3rd party VOC testing soon to be released. Maybe that will throw some light on the discrepancies.

    Future Plans
    Depending on feedback from MoleKule and the results of their forthcoming new data I will do more testing.

    Test NTP plasma devices

    There are a couple of manufactures that produce devices that look promising. Iíd like to investigate

    Investigate the latest generation of MOS sensors. Renting PID meters and repeated GC/MS testing can get expensive. Low cost testing instruments would be a game changer.

  2. #2
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    Thank you Randy - for taking the INCREDIBLE amount of time you have investing in doing this testing and in writing up this and other posts. It is greatly appreciated.

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    How is the Terrabloom used/installed? I'm just seeing the filter. Is this installed into the duct-work?

  4. #4
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    Quote Originally Posted by argenan2 View Post
    Thank you Randy - for taking the INCREDIBLE amount of time you have investing in doing this testing and in writing up this and other posts. It is greatly appreciated.
    Thanks - I've actually enjoyed the research. A couple of decades ago this kind of stuff was a pain. Required a trip to an academic library. Now with the internet and availability of journal articles it's much easier.

    All I want is consumers to be educated to challenge misinformation - especially from manufactures. I'm really stunned that these folks don't test (in real world environments) the stuff they sell.

    My links on the TerraBloom filter/fan were mangled.
    Here's the Carbon filter:
    https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

    Here's the attaching fan:
    https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

    It's about 1/3 the price of Austin's strongest gas filter.

    The fan fits on top of the filter for a reasonable tight fit.

    Keep in mind:
    1. My results were astounding. Up to a 65% reduction.
    2. These test was done when the filter was only a few weeks old. Haven't tested since. I don't know how long the filter will take to saturate. Remember when carbon saturates it can release the stored VOCs.
    3. The filter, as far as I can tell, does not have any additives. The Austin Filter does. Additives can trap some VOC that carbon alone is not that good at. Also additives can permanently trap VOCs
    4. A friend of mind claims the fan/filter has a smell. Doesn't bother me.

    Also Remember - VOCs in the air come from VOCs in liquid/solid states on your surfaces. Just because you're removing them from the air doesn't mean you are eliminating the source.

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    Hello Randy, thank you for your reply. I know it's not fair to ask but for someone untrained scientifically or HVAC-ly, I'm really at a loss as to which solution to choose for my family. I guessing VOCs are an issue just due to materials and furniture in the house. I have a AprilAire HVAC filter so I need something more than that. I like the effectiveness you showed with the Terrabloom but without an ability to know when it is saturated, it makes me nervous; I like the AustinAir because it has the most charcoal of any on the market and (I think) it is treated to not release the VOCs when saturated; I like the look and idea of the Molekule but it doesn't seem to be showing that effective in real-world conditions. Would some combination be more effective than choosing just one? Would I be "safe" with the Terrabloom as long as I commit to changing the filters at a set interval? Again, I know it's not fair to ask. I couldn't figure out how to message you directly, so as not to put you on the spot publicly! I'm sorry for that! p.s. I sent you a friend request thinking that might help. p.p.s. I can't remember if you already commented on the VOC testing done by University of Minnesota on the Molekule?

  6. #6
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    Quote Originally Posted by argenan2 View Post
    Hello Randy, thank you for your reply. I know it's not fair to ask but for someone untrained scientifically or HVAC-ly, I'm really at a loss as to which solution to choose for my family. I guessing VOCs are an issue just due to materials and furniture in the house. I have a AprilAire HVAC filter so I need something more than that. I like the effectiveness you showed with the Terrabloom but without an ability to know when it is saturated, it makes me nervous; I like the AustinAir because it has the most charcoal of any on the market and (I think) it is treated to not release the VOCs when saturated; I like the look and idea of the Molekule but it doesn't seem to be showing that effective in real-world conditions. Would some combination be more effective than choosing just one? Would I be "safe" with the Terrabloom as long as I commit to changing the filters at a set interval? Again, I know it's not fair to ask. I couldn't figure out how to message you directly, so as not to put you on the spot publicly! I'm sorry for that! p.s. I sent you a friend request thinking that might help. p.p.s. I can't remember if you already commented on the VOC testing done by University of Minnesota on the Molekule?
    No worries -feel free to query anytime.

    Here's what I suggest if you can afford it (130 - $450):
    Test at least one room in your home by GC/MS(gas chromography/ mass spectrometry)
    Here are two labs I've used:
    1. https://homeaircheck.com/products/ Least Expensive.
    2. https://www.fikeanalytical.com/ High Quality, recommended

    You can also use a passive badge(s)
    https://www.assaytech.com/ Call these guys and tell them your concerns.

    I think the most important first step is to determine if you have an issue with specifics on amount and types of VOCs.

    I've got many of the same questions as you!

    I'm currently working on an inexpensive meter based on the latest MOS technology. If affordable measuring devices become available to measure VOCs we (end users) could force the manufacturers to put up or shut up. Until then PID meters and GC/MS is all we got.

    So far I've only seen carbon/adsorptive device work, but I haven't given up. Still need to test Non-Thermal-Plasma. MoleKule is suppose to have some new data available that might explain my negative findings. Could be the MoleKule takes much, much longer to be effective.

    Regards and good luck.

  7. #7
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    Quote Originally Posted by argenan2 View Post
    Hello Randy, thank you for your reply. I know it's not fair to ask but for someone untrained scientifically or HVAC-ly, I'm really at a loss as to which solution to choose for my family. I guessing VOCs are an issue just due to materials and furniture in the house. I have a AprilAire HVAC filter so I need something more than that. I like the effectiveness you showed with the Terrabloom but without an ability to know when it is saturated, it makes me nervous; I like the AustinAir because it has the most charcoal of any on the market and (I think) it is treated to not release the VOCs when saturated; I like the look and idea of the Molekule but it doesn't seem to be showing that effective in real-world conditions. Would some combination be more effective than choosing just one? Would I be "safe" with the Terrabloom as long as I commit to changing the filters at a set interval? Again, I know it's not fair to ask. I couldn't figure out how to message you directly, so as not to put you on the spot publicly! I'm sorry for that! p.s. I sent you a friend request thinking that might help. p.p.s. I can't remember if you already commented on the VOC testing done by University of Minnesota on the Molekule?
    On a closer read I realize I didn't answer all your issues:

    1. The Austin Air WILL release VOCs when saturated or even before. I've measured this myself with a PID meter. I increased the temperature to close to 80^F in a room and more VOCs were coming out than going in. This is not a problem specific to the Austin unit but to All carbon devices. It's true the Austin does have an additive, potassium idodide, but this will not stop the release of VOC stored in the carbon when saturated or when temps slightly raised. Also not that most Austin Filters do not have the additive. It's only available on the HP+.

    2. I don't know if multiple devices, used at the same time, will increase effectiveness or not. It might.

    3. I really like the concept of device that work off the principle of oxidation. I just haven't seen any effectiveness yet. I'm looking forward to MoleKule releasing their new data on VOC. If this never appears or MoleKule doesn't respond directly then I think we can conclude that the device does not significantly reduce VOCs.

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    Randy
    Good summary. Well researched and clearly written.

    Nicely done!!

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    Randy

    Last night I did some more thinking on why the Molekule device did not register any improvement in the indoor air quality. I believe the answer is air flow, or in this case, lack thereof.


    When you determine the efficiency of an air cleaner in an indoor space, there are several factors to consider.
    1. The efficiency of the device
    2. Outdoor to indoor particle transfer
    3. System run time
    4. Activity in the space
    5. The power of the device to deliver ACH or Air Exchanges per hour.

    The last element is critical. If you do not have sufficient air flow through the device, the other factors will overwhelm the ability of the device to remove particles and VOC's. For example, a hospital isolation room requires 10 to 12 ACH for acceptable air quality. A clean room requires from 10 ACH to over 200 ACH to achieve the levels of clean air required.

    From what I have read the Molekule device delivers 80 cfm. This is not sufficient to make a significant difference in air quality in an occupied space. It might be OK in an unoccupied space or in a space where people are sleeping and there is little, if any, activity.


    So, it is not just the air cleaning technology used but also the rate at which the indoor air is exposed to the air cleaner. You can't have clean air without both.

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    Quote Originally Posted by breathe easy View Post
    Randy
    Good summary. Well researched and clearly written.

    Nicely done!!
    Thanks breath easy. I know your an evidence base sort with a deep professional interest in this stuff so I appreciate your comments.

  11. #11
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    Quote Originally Posted by breathe easy View Post
    Randy
    Good summary. Well researched and clearly written.

    Nicely done!!
    Thanks breath easy. I know your an evidence base sort with a deep professional interest in this stuff. Your comments are appreciated. your comments.

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