An air purifier has an ABSOLUTE SEAL when there is no leakage through doors that are or become ill fitting over time. The pressure buildup in a unit can become quite intense forcing UNFILTERED AIR through cracks. Doors that are not sealed well or that are ill fitting provide an easy exit through openings that allow unpurified air to bypass some or all of the filters.How does the Foust SERIES 400 achieve the absolute seal necessary to prevent bypass? By STACKING our filter components vertically, the air must pass through them. No doors, no latches, no warping, NO AIR BYPASS. All air entering the system leaves the system filtered. DOES THE PURIFIER YOU ARE CONSIDERING HAVE TRAYS THAT SIT IN TRACKS?If the purifier you are considering has filter trays, be sure that the tracks they slide into are tight and well sealed. If the trays do not fit snugly into these tracks, the air flowing through the unit will bypass the loose filters and exit the unit unfiltered. Further, if the trays do not fit tightly, they will rattle in their tracks resulting in noisy operation.3.

DOES THE AIR PURIFIER CONTAIN PLASTIC PARTS OR OFFENSIVE SYNTHETICS?If you are a chemically sensitive person, plastic or objectionable synthetics are not acceptable to you. Check for those which are difficult to see. Some units look very appealing yet may contain plastic parts and irritating adhesives which are not easily visible.Our SERIES 400 has been designed with the chemically sensitive person in mind. Pre and post filters contain no adhesives. HEPA filters are made without glue. There is no outgassing on our HEPA at temperatures under 500 degrees! Our cabinets are finished with a specially processed, very durable powder coat finish.If you purchase an E.L. FOUST air purifier with a UV bulb, NO ozone is created by the air purifier.Don't be impressed by outlandish claims of how many thousands of cubic feet of air per hour or per day are moved by an air purifier. Such claims are quite meaningless in themselves because they represent only one variable among many that determine airflow.

True output can only be determined by figuring the relationship between motor CFM (cubic feet per minute) and resistance (the number and density of filters through which the air must flow). cyclone air cleaner partsThis number is, by necessity, always quite a bit lower than the high volumes advertised and indicates the ability of the entire system to operate efficiently.air cleaner rentals torontoSmall blade-type fans are just not able to push air through several filter components. mold air purifier consumer reportsThe Foust DOUBLE SQUIRREL CAGE blower fan provides the power needed to push air through our intelligently designed series of filters. Even our economical # 160 series purifiers for homes, offices, and cars use squirrel cage fans for greater efficiency.

Keep in mind that purifiers that are loaded with filter components suffer in air output if they do not have a powerful enough motor. If you inspect a purifier which has been advertised as having several filter components but does not produce good airflow, then the motor is not powerful enough to push through all those components and invites the bypass problem we discussed earlier as well as backwash (where air builds up on the motor compartment and exits back through the intake area. This creates what's called a roll effect where air never reached the filter beds).Our motor-blower system is designed to provide OPTIMUM AIRFLOW THROUGH THE FILTER BEDS FOR THE MOST EFFICIENT AIR FLOW AND PURIFICATION.Ask this question: Is the quoted efficiency of the HEPA based on loose material purchased by the company that they themselves install in a frame and glue in place? Or is the quoted efficiency based on a HEPA already completed and tested as a unit? If the company has done their own installation from loose HEPA material you must ask if that completed product has been tested once assembled.

Insist that the purifier you purchase contain a HEPA filter that has been tested after assembly.THE FOUST SERIES 400 HEPA FILTER IS TESTED AFTER ASSEMBLY AS A COMPLETE UNIT AT THE FACTORY UNDER THE HIGHEST STANDARDS.The E.L. FOUST COMPANY offers a 90% refund of purchase price within 30 days for whatever reason-no arguments, no hairsplitting, no hassle. Just let us know of your intention to return your purifier, and once we receive it in good condition, we will refund your money within 7-10 days.At Alen, we're all about helping people Live Better. We do that by creating high quality air purifiers to help you find relief from allergies, asthma, pet concerns, secondhand smoke, troublesome odor or other respiratory issues. Our commitment to you doesn't stop there. When you buy an Alen HEPA Air Purifier, we promise to keep you breathing pure air for a lifetime. This is a promise we stand by. Yes, there is some legal language below that our lawyers insist we include. The reality is, we put customers first.

If there is ever an issue with your Alen HEPA Air Purifier–either 1 year or 20 years from now, we will repair or replace it, as long as you are maintaining your air purifier by replacing its filter on a regular basis. And by the way, we are the first —and only—company in the air purification industry to do this. Just call us (800-630-2396) or complete our online form so we can arrange shipment to our service center at no cost to you. I loved my Alen HEPA Air Purifier and when it failed 5 years later, I was so disappointed. Now retired, my income forces me to make tough decisions. When I contacted Alen, they immediately reminded me that the product had a lifetime warranty, no questions asked and in 4 days, I had a new machine. So, I started thinking....what other product offers a 'lifetime' warranty without a list of exceptions? I can't think of any. Thanks Alen for your great product, your service and the promises you keep.Will in Maine from Lincolnville, Me 1/27/13 We had an Alen HEPA Air Purifier that began to malfunction, and I was so disappointed - this purifier was an investment (we bought 2 of them) and it was needed for an allergy sufferer.

But thanks to Alen Corp., I made the phone call to see if it was covered under warranty and hoped they'd repair it and much to my relief, they had all my info and after troubleshooting, they determined to replace the unit. I am so pleased. This action right here, that this company stands by their warranty, has made up my mind that if we need another product like this in the future, we will shop with Alen.happy camper from land of 10,000 lakes 02/03/13 We recently had a power surge come through the house and take out one of our 2 AlenAir 350 HEPA filters. I emailed AlenAir telling of my problem and they immediately began processing a replacement filter for standing by their lifetime warranty. We'll be customers for life. Craig from Richmond, VA 04/24/13 I now own 4 Alen products and am very happy with them. There is a noticeable improvement in air quality with this product. The air purifiers run 24/7 and really help reduce the dust in the house. They are kind of pricy but they are of good quality, do what they advertise, and the company really stands behind the product.

The customer service folks are very helpful and they help to resolve any issues that might arise. I had a defective product and they immediately sent out a new air purifier. So to sum it up, really good product that is costly but worth it. This is one of those times when you get what you pay for!!! I have had this air purifier for almost 5 year to help combat asthma. Since setting it up in my bedroom, my asthma issues (caused by having 4 cats) have pretty much disappeared. Regarding customer service, I recently had a problem with the purifier, and Alen acted promptly to fix the problem. I was amazed by how quickly they reacted (or that they reacted at all), given the age of the purifier. I highly recommend this product. hockey5 from Buffalo, NY 12/26/12 I bought an Alen unit back in 2009 and we run it constantly. It died last month and Alen sent us a new one - I was truly amazed at their customer service and warranty follow through. In today's world, you just don't come across many companies like this one!

Thank you Alen for standing by your product so admirably!Sonya from Kentucky 9/3/12 Alen will, at its option, either furnish a replacement part or replace your air purifier provided the product is determined by Alen to be defective as a result of faulty material or workmanship while in normal use. Replacement parts or units will, at Alen's option, be either new or refurbished. Alen's sole obligation under this warranty is to replace defective parts or replace your air purifier free of charge. All parts or units that are replaced become the property of Alen. This warranty will be valid only for units in possession of the original purchaser. Proof of purchase must be presented to Alen's warranty service representative. To help us validate your warranty, we encourage you to register your Alen HEPA Air Purifier. Your Lifetime Limited Warranty remains in effect if: Please keep in mind that the warranty is currently only valid in the country of purchase. Because Alen cannot ensure reliable voltage and power consistency in other countries, taking your unit out of the US will void the warranty.