We've all seen those air purifier infomercials. But can can allergy relief be as easy as spending $449 for a home air purifier? Last year over 4 million air purifiers were sold in the US. And while allergies rank #1 as the reason people bought an air purifier the rise of childhood asthma (up 60% over the last 10 years) is a close second.

The strong competition between manufacturers is creating confusion for consumers. According to one industry analyst:

"Manufacturers are battling over whether ozone purifiers, ion purifiers, and the no-replacement-filter-type purifiers are best in the minds of consumers"

According to Rich Mayer, a Research Scientist who specializes in Air Purification Technology 3 things stand out:

After testing 314 air allergy purifiers we discovered that most experts still agree that a HEPA filters are the most efficient for removing pollen and dust. Next is UV light - which can kill bacteria and viruses that can contribute to allergy reactions.

5 things you should know before you buy an Air Purifier

#1: Replacement Filters are Over-Priced

In Japan air purifiers include 2-3 extra replacement filters. WHY? Because the Japanese think ahead.

U.S. manufacturers realize American's don't think ahead so they overcharge. Once you purchase an air purifier you'll be stuck paying what they ask. (Reminds me of my $89 inkjet printer -the replacement cartridges are $28!)

Remedy: Ask for filter prices first. Every 6-12 months you'll need to change filters. And anything over $25 is too much.

Buying Hint: Ask for a discount on extra replacement filters before buying.

#2: Avoid Purifiers That Say: "No Replacement Filters"

The idea sounds great but once you've seen a dirty HEPA filter (HEPA's are a cloth-like filter which holds dust and pollution) you realize the ones without filters aren't catching very much dust or pollen - YOUR LUNGS ARE!

"No Replacement Filter Models" include:

Ionic Breeze

Oreck Models (they contradict themselves on their website. You have to replace filters, but they aren't HEPA)

Remedy - Get an air purifier that has affordable replacements. HEPA is important if you have allergies.

#3: "Fanless" Air Purifiers Won't Move Enough Air

The ionic purifiers sell you on how quiet they are and how little electricity they use. The problem is they don't move any air.

(Note; Because of this problem Sharper Image went to fans in their new models)

Remedy: Avoid purifiers without fans.

#4 Avoid Loud Fan Motors

A few people have emailed me that after buying an air purifier they couldn't sleep.

Remedy: For a super quiet fan ask for one with brushless motors. Read the box for decibel levels. 20-35 decibels is quiet enough for sleep.

#5: It Won't Do The Square Footage On The Box

I called Oreck when their new $700 tower was listed as covering 1100 square feet. "How Many Times Does It Change The Air In The Room?" (which means how many times it will change all the air in that room). They didn't know. Finally a tech said: "One per hour". That's poor.

Remedy: Make sure to ask for 4-9 "Changes Per Hour" per Square footage.(You may have to call the manufacturer) Square Footage as listed on the box is also based on an empty room.

How to Choose The Right Technology

Here are some guidelines to match the basic technologies to your needs:

#1 HEPA, Pre-filter, Neg/Ion, Plasma Grid = Helpful for allergies and asthma, some odors

#2 Carbon, Charcoal, Ozone = Helpful for odors, smoke, animal smells, chemical sensitivity, VCO's, and immune system

#3 UV, TiO2, Plasma Grid, Ceramic = Helpful for immune system (colds, flu, viruses, pathogens), and eliminating musty odors

New Sensor Technology There is a cool new technology from Japan that detects pollen. It promises to bring greater allergy relief. It continuously adjusts the purifier to the room saving electricity and guesswork.

In the end the home Air Purifier I found became one of the 3 parts of the plan that eliminated my allergies.