Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 27
  1. #14
    Join Date
    Jan 2005
    Location
    yadkinville nc
    Posts
    532
    Quote Originally Posted by pmeunier View Post
    But winter is when you need the filtration the least. Water evaporation on the A/C coil is just one more reason to use a dehumidifier. You can't rely on the A/C to control humidity unless it has a special mechanism for that hooked to a dehumidistat. Even then you can't rely on it in the spring and fall. Use an A/C for cooling, and a dehumidifier to dehumidify.

    What would you say to someone who relies on a dehumidifier for heating during fall and spring, without any temperature control (thermostat)? To me, relying on the A/C for humidity removal, without a dehumidistat, is as absurd. Both humidity and temperature need to be controlled.
    Why do you need less filtration in the winter? Dust is dust is dust anytime of year. Most household dust is actually all the crap off of us dead skin cells etc. Not even taking animal dander into effect if pets in home. I never said anythng against whole house dehumidification, but it can be done with the ac unit. Look at the new Humidtrol Lennox has uses condensing unit and evap but has a three way solenoid and a reheat coil. A 2 stage unit will provide great results as well
    duct tape and cable ties will fix anything, if that don't work add a 90-340.

  2. #15
    Join Date
    Aug 2003
    Posts
    907
    Quote Originally Posted by pulse21 View Post
    Why do you need less filtration in the winter? Dust is dust is dust anytime of year. Most household dust is actually all the crap off of us dead skin cells etc. Not even taking animal dander into effect if pets in home. I never said anythng against whole house dehumidification, but it can be done with the ac unit. Look at the new Humidtrol Lennox has uses condensing unit and evap but has a three way solenoid and a reheat coil. A 2 stage unit will provide great results as well
    I said that from the perspective of seasonal allergies, because there's no pollen or mold from the outside in freezing weather.

    The Lennox system was included and accounted for in my statement "unless there is a special mechanism". Even so, I believe that the Lennox won't work if there isn't a cooling load so you still need a dehumidifier if you want control.

    Cheers

  3. #16
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,637
    Quote Originally Posted by breathe easy View Post
    Whoa, Teddy!
    Keeping humidity below 50% will reduce dust mites and molds. It is not a panacea and it certainly will not keep mattresses, pillows and carpeting mite free. (Look at the Arlian studies that are the basis for the humidity claim).

    Keep in mind that dust mites are allergenic dead or alive. Even if lower humidity were capable of killing 100% of the dust mites (which it is not) you will still have millions of dust mite carcasses in beds, pillows and carpeting. Smooth floors as well as dust mite proof encasements for beds and pillows are a good idea for anyone with allergies.
    I am the guy that Larry Arlian going on testing humidity control on homes. After meeting him through a mutual friend, we discussed the possibility of controlling humidity in a home to control dust mites. He expressed doubt. My company funded the study and provided dehumidifiers for five dry homes and five normal homes. By the end of the summer, it was difficult to find a mite in dry homes. Larry presented the results of this limited study to EPA and recieved funding for a two study on 75 homes. The plan was 25 non-a/c, 25 dry homes (dehumidified) and 25 a/c homes. By the end of the two year study, mites in the dry homes were too few tobe significant. This included matteresses and pillows. If you keep the home <50%RH, dust mites will not reproduce. Transient mites will die in two weeks. It takes two years for the dust mite allergens to break down to the point of not affecting people. I provided the dehus for the all of studies. Unfortunately, most allergist like a/c contractors do not care about the finer points of indoor air quality and comfort. None of these homes had mechanical fresh air ventilation. On a more positive side, this has provided me an mission in life. Regards Dehu TB

  4. #17
    Wow, Teddy!
    I am impressed and I am not being the least bit facetious. These are some of the best studies on the effects of humidity on controlling dust mites.

    I have some doubts about pillows and mattresses since there is moisture created by human perspiration. However, at least one of the Arlian studies shows a decrease of 96% - even in matresses and pillows. So I think you have a pretty strong case for dust mite control through dehumidification.

    But your point about taking two years for the decomposition of dust mite carcasses and feces supports the need for encasements for pillows and mattresses and possibly smooth floors as well. It doesn't make much sense for the dust mite allergic person to wait two years before they start taking sound and proven environmental allergen controls. My point is not that dehumidification is not an important part of controlling a home environment. It is just that it is not the only step people should take.

  5. #18
    Quote Originally Posted by teddy bear View Post
    I am the guy that Larry Arlian going on testing humidity control on homes. After meeting him through a mutual friend, we discussed the possibility of controlling humidity in a home to control dust mites. He expressed doubt. My company funded the study and provided dehumidifiers for five dry homes and five normal homes. By the end of the summer, it was difficult to find a mite in dry homes. Larry presented the results of this limited study to EPA and recieved funding for a two study on 75 homes. The plan was 25 non-a/c, 25 dry homes (dehumidified) and 25 a/c homes. By the end of the two year study, mites in the dry homes were too few tobe significant. This included matteresses and pillows. If you keep the home <50%RH, dust mites will not reproduce. Transient mites will die in two weeks. It takes two years for the dust mite allergens to break down to the point of not affecting people. I provided the dehus for the all of studies. Unfortunately, most allergist like a/c contractors do not care about the finer points of indoor air quality and comfort. None of these homes had mechanical fresh air ventilation. On a more positive side, this has provided me an mission in life. Regards Dehu TB

    Teddy
    I have been thinking about your response - especially the part where you talk about allergists not caring about the finer points of indoor air quality and comfort. I take it you provided the dehumidifiers for these studies with the anticipation that once the allergists understood that reducting humidity below 50% controlled dust mites that the medical community would be recommending dehumidifiers to their patients. I take it the return has not met your expectations. Unfortunately, your experience is typical. I know of manufacturers of HEPA air cleaners and other products that have had similar results.

    The problem is what I call "connecting the dots." Just because most allergic people are allergic to dust mite proteins and dehumidifiers control dust mite populations, it does not mean that there is a direct health benefit. The missing lines between the dots is a double blind medical study showing improved symptoms related to the use of dehumidifiers.

    I have a running argument with my air filter friends on this very point. Their position is proper high efficiency filtration reduces allergen exposure. Therefore it must have a health benefit. But there is no medical study that supports this conclusion - which is why all consumers should be leary of such claims.

    The best study showing the effectiveness of environmental controls is the Inner City Asthma study. This showed that a combination of different environmental controls including encasing mattresses and pillows. a HEPA air purifier, a HEPA vacuum and roach and rodent extermination dramatically improved allergy driven asthma symptoms.

    You will be happy to learn that IAQ has become a larger concern for allergists. In fact the American College of Allergy, Asthma and Immunology is having a special one day session on IAQ before their Annual Meeting in November. It should be interesting.

  6. #19
    Join Date
    Dec 2002
    Posts
    143
    BreathEasy,

    Have a simple question for you I just assume take offline. Is the sales@allergyclxxx.com a good email for you?

    Thanks,
    Matt

  7. #20
    Yes. You can contact me through our website.

  8. #21
    Join Date
    Dec 2002
    Posts
    143
    Thanks, just sent an email from he8833

  9. #22
    Join Date
    Aug 2003
    Posts
    907
    Quote Originally Posted by breathe easy View Post
    Teddy
    (...)
    I have a running argument with my air filter friends on this very point. Their position is proper high efficiency filtration reduces allergen exposure. Therefore it must have a health benefit. But there is no medical study that supports this conclusion - which is why all consumers should be leary of such claims.
    (...)
    All consumers should be leery?
    How about when you are outside and start having incapacitating sneezing fits, and go inside, close the windows and start a HEPA filter on high, and 30-45 minutes later the itching, runny nose and sneezing have completely stopped. You go outside and it starts again. That experience has been highly reproducible for me and some friends on some days. Anecdotes don't make a scientific study, but the benefits are so obvious in some cases that there is no need for a medical study... I could understand if you meant that non-allergic consumers should be leery of health benefit claims due to filtration, but all?

  10. #23
    Join Date
    Jan 2005
    Location
    yadkinville nc
    Posts
    532
    [QUOTE=pmeunier;1599295]I said that from the perspective of seasonal allergies, because there's no pollen or mold from the outside in freezing weather.

    The Lennox system was included and accounted for in my statement "unless there is a special mechanism". Even so, I believe that the Lennox won't work if there isn't a cooling load so you still need a dehumidifier if you want control.

    Cheers[/QUOTE

    I understand there are more allergies in the summmer so from that standpoint you are correct. I was reffering to also control dust as well, which can trigger allergies. The Lennox Humiditrol is a "special mechanism" When set up properly with the correct stat it will operate the humiditrol without a cooling load. It's a pretty sweet set up. It will run the AC iwth the special reheat coil in the circuit for dehumidfication without uncomfortable drops in temp. See I agreed with you just did'nt explain it good
    duct tape and cable ties will fix anything, if that don't work add a 90-340.

  11. #24
    pm
    I am glad your allergy symptoms improve when you go into your "oasis" of a room with a HEPA air purifier on high. Exactly the same thing happens for me. That is why I always sleep with a HEPA air purifier running constantly. And if it is working, keep doing it.

    That is why it is hard to believe that the medical studies that have been done (unless they focus on one allergen like cat dander) do not support our experience. I believe this is due to two factors:

    1. Allergy prone individuals are usually allergic to more than one allergen. While the air purifier or high efficiency air filter may reduce exposure to allergens that stay in the air for an extended length of time such as dander, mold, certain types of pollen, etc. it does little or nothing to reduce exposure to things like dust mite droppings. Since most people with allergies are allergic to dust mite proteins, their symptoms do not improve. That is why keeping humidity below 50&#37; and encasements for mattresses and pillows are so important.

    2. People's allergen thresholds vary widely. What is sufficient allergen reduction for some people is not enough for others. Very small exposures for some people are sufficient to set off their allergic reactions. For these people air filters and other air cleaning devices simply don't lower allergen levels enough to achieve a reduction in symptoms.

    That is why consumers need to be leery of claims that one device is a cure-all panacea for all. It is also why a comprehensive allergen avoidance program is the most effective.

  12. #25
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,637
    [QUOTE=pulse21;1601591]
    Quote Originally Posted by pmeunier View Post
    I said that from the

    Cheers[/QUOTE

    I understand there are more allergies in the summmer so from that standpoint you are correct. I was reffering to also control dust as well, which can trigger allergies. The Lennox Humiditrol is a "special mechanism" When set up properly with the correct stat it will operate the humiditrol without a cooling load. It's a pretty sweet set up. It will run the AC iwth the special reheat coil in the circuit for dehumidfication without uncomfortable drops in temp. See I agreed with you just did'nt explain it good
    The Humiditrol does a small amount of over-cooling when dehumidifing. A portion of the heat is rejected to the outside. The more negative point is the poor dehumidification efficiency. Less than 2 pints of moisture are removed per KWH. The high efficiency dehus are upto 5-7 pints per KWH. Another problem is that you have 3-4 pints per ton of a/c moisture retained on the a/c coil at the end of dehu cycle. This meams 6-10 lbs. of moisture is retained on the coil at the end of the dehumidification cycle. Until this moisture re-evaporates back into the house, the coil and ducts are wet enough to grow mold. One pint of revaporation moisture raises the %RH of 1,000 sqft of house 9%RH. This means you will not be able to recirculate any air between cooling/dehumdifing cycles with a large wet coil. You are removing moisture a grossly over-sized, inefficent dehumidifier. This is as bad as an over-sized a/c.
    I am impressed with the blind loyalty of many a/c contractors who insist on tring to control humidity with complicated, inefficient a/c equipment compared to simpler more efficient dehumidifiers. It's interesting challenging tring to introduce the ventilating dehu as a more practical device to provide IAQ and comfort to modern home. Regards Dehu TB

  13. #26
    Join Date
    Aug 2003
    Posts
    907
    Quote Originally Posted by breathe easy View Post
    pm
    (...)
    That is why consumers need to be leery of claims that one device is a cure-all panacea for all. It is also why a comprehensive allergen avoidance program is the most effective.
    Oh right. I understand the "no cure-all panacea for all" and that there are other things to do besides getting a HEPA filter. Yet it should be possible to write a document that says which health benefits are likely or possible from using a HEPA filter in manner X, Y or Z...

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event