Do those HEPA filters actually do anything, or is it just a scam to have another machine in the house? Are all of those types of .3 micron “particulate matter” truly a health risk?
http://www.vornado.com/airclean.html
(link provided just for informational purposes; not trying to endorse in any way)
I don’t know, but I work in a Class 1 cleanroom, where all the air is completely replaced nine to ten times a minute with ULPA* filtered air, and people still get colds, suffer from allergies, etc. in there.
If “Mother Nature intended us to breathe clean air”, as the link said, then why do we have so much mucus and so many hairs in our sinuses?
*HEPA stands for High Efficiency Particulate Air (or accumulator); ULPA stands for Ultra Low Penetration Air. ULPA filters can remove particles that are about twice as small as the smallest ones that HEPA filters can get.
Mother Nature also intended us to eat meat raw with rancid fat. Mother Nature very much intended women to die around 40. Mother Nature intended us to get sick often to provide vectors for all her parasites, obviously her favorite invention. (Most animals, even multicelled ones, are parasitic. Everything has at least one parasite.) In short, whenever I hear someone say something’s ‘all natural’ I want to punch his all-natural piehole with my all-natural fist. If y’all are lucky, I might write a Pit thread on this.
My father has sleep apnea, a condition that causes him to stop breathing momentarily and wake from his sleep up to 50 times a night. He now has a piece of equipment, a C-PAP, that forces air into his respiratory system so that the momentary lack of oxygen doesn’t wake him. He noticed that the constant flow of air gave him a runny nose and aggravated his allergies, so he bought a HEPA air filter and tried it. Worked like a charm - no more waking, no more allergies.
This question was asked two weeks ago but the moderator cut the thread. I’ll repeat below what I wrote then:
I have a several pets and live in a large city that is warm and humid half the year so we have dander, mold, pollens, and urban air polution. Perhaps as a result, several of my family members have chronic allergic rhinitis. Consequently, I have been interested for some time in techniques to purify indoor air. I read reports on allergies and the means to prevent them in Consumer Reports, selected magazines and newspapers, and in scientific journals. (I generally don’t look for such information in Omni, the National Enquirer, or publications from the EPA.)
In general, all the reliable sources seem to say that HEPA filters may (repeat, may) help. Certainly they do take particles out of the air (making lots of noise and a big dent in your pocketbook in the process). However, there seems to be very little evidence that filters reduce allergy symptoms. The reliable reports should probably be taken as “damning with faint praise” and a sensible person would not waste her money but I, nevertheless, ended up with two expensive HEPA filter units. I should have saved some money and bought copper bracelets; they probably would have worked just as well.
Here is what Reisman RE, Mauriello PM, Davis GB, Georgitis JW, DeMasi JM concluded from “A double-blind study of the effectiveness of a high-efficiency particulate air (HEPA) filter in the treatment of patients with perennial allergic rhinitis and asthma” (published in J Allergy Clin Immunol 1990 Jun;85(6):1050-7): "For the total study, there was
no difference in the total symptom/medication scores or individual symptom scores during the placebo and active-filter periods. Analysis of the last 2 weeks of each filter period in which respiratory infection was absent demonstrated definite differences in total and individual symptoms, suggesting active-filter benefit. Patients’ subjective responses also suggested benefit from the filter. The overall impression is that the HEPA filter can reduce allergic respiratory symptoms.
On the other hand, here is what Wood RA, Johnson EF, Van Natta ML, Chen PH, Eggleston PA concluded from “A placebo-controlled trial of a HEPA air cleaner in the treatment of cat allergy” (published in Am J Respir Crit Care Med 1998 Jul;158(1):115-20): “Although the combination of a HEPA room air cleaner, mattress and pillow covers, and cat exclusion from the bedroom did reduce airborne cat-allergen levels, no effect on disease activity was detected for any parameter studied.” It is worth reading at least the whole abstract which can be found at http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9655716&dopt= Abstract.
As for taking things out of the air other than allergens, the activated carbon prefilters should work. However, the only non-allergen indoor air “contaminant” I know of that actually causes any health problems is radon and the filters won’t remove radon.
I have one of those small air filters for my bedroom. My family says that I snore much less if it’s on while I’m sleeping. There you go, one data point.
How about cigarette stench? Do they help at all, even cosmetically?
Do they work?
Yes.
We have a HEPA filter on our vacuum, and it really makes a difference with the amount of dust around the house… there is hardly any. As well, we (or, my wife) has a Cat. I am terribly allergic to cats (it came with the wife). My allegies haven’t bothered me since we got that vacuum. So, a vote here for they really work.