1. WHAT DOES "ABSOLUTE SEAL" MEAN AND WHY IS IT SO IMPORTANT? OR…DOES THE PURIFIER YOU ARE CONSIDERING HAVE DOORS?
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.
THE FOUST SERIES 400 HAS NO DOORS, NO LATCHES.
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. BYPASS IS IMPOSSIBLE. No doors, no latches, no warping, NO AIR BYPASS. All air entering the system leaves the system filtered. Simple!
2. 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.
OUR SERIES 400 has no tracks. Our filter components are stacked vertically eliminating tracks, bypass and rattling.
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.
4. DOES THE AIR PURIFIER WITH AN ULTRAVIOLET LIGHT CREATE OZONE?
If you purchase an E.L. FOUST air purifier with a UV bulb, NO ozone is created by the air purifier.
5. WHAT IS THE TRUE CAPACITY OF THE PURIFIER'S MOTOR?
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). This 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.
6. IS FAN DESIGN IMPORTANT?
Yes! Small blade-type fans are just not able to push air through several filter components. The 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.
7. WILL MY PURIFIER HAVE GOOD AIRFLOW?
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.
8. HOW DO I EVALUATE CLAIMS MADE ABOUT THE EFFICIENCY OF THE PURIFIER'S HEPA FILTER?
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.
9. WHAT IS THE REFUND POLICY?
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.
