(And their maintenance is complicated. See below.)
2. Now you have to 'quickly' wipe the dust from each of the three collection bars of the grid.
3. Now you have to turn the entire unit upside down for three seconds before replacing the collection grid.
4. They stress that you must allow the collection grid to dry completely before putting it back in the main housing. But wait - there's more! This is not the only cleaning you have to do. The manual says that if the purifer makes noise when it's working, you have to perform a much more thorough cleaning of the grid and ionizing wires. You have to
6. Wash the grid with warm soapy water, rinse, and then allow
to dry for 24 hours before returning to unit.
7. While the unit is still apart, you have to turn the main housing upside down several times before replacing the collection grid. The purpose for this, they say, is to remove any accumulated particles from the ionizing wires. However, don't forget, you'll have to let the grid dry for 24 hours before putting it back in the unit. There's even more! Sharper Image ships a list of Frequently Asked Questions with their purifer. From that list you learn that if basic cleaning fails to stop the noise, you should try these extra cleaning instructions:
9. Invert, rotate and shake the unit aggressively for several minutes. They explain that this will cause internal cleaning beads to scrape the ionizing wires inside the unit. They warn us that this procedure may require several attempts.
10. With the grid removed, up-end the unit and shake out collected dust from the base. Now, if the noise still persists:
12. Open the back cover to expose the UV lamp area. (GP model only.)
13. Use a can of compressed air to blow debris and dust from the wire and from the other visible parts inside the unit. (They suggest that one could also use portable hair dryer.) If the noise STILL still persists, they suggest you try the following. (They also suggest you do it 'cautiously'):
15. Use a cotton swab attached to a stick, or cardboard from a dry-cleaner hanger or a long tube of rolled newspaper to wipe down the ionizing wires inside. They warn you to use only gentle pressure to avoid breaking the wires.
16. Blow away dust with compressed air.
17. Reassemble the unit. They warn that this last delicate chore should be a "last-ditch" effort, since too much pressure could snap the wires and cause the unit to become defective.
By the way, elsewhere in the Sharper Image documentation you are advised that you will have to at least do the first stage of cleaning every time you light a candle near the unit, or when you enjoy a fire in a nearby fireplace.
Remember, you have to clean the Sharper Image purifier at least 26 times a year.
Our New-Aire XJ-3000C typically needs maintenance about once a year. (In fairness, if you don't mind vacuuming the front of the filter unit every couple months of you can extend the life of the filter to as long as two years. Just a moment or two every couple of months.)
On Sharper Image's $500 GP model, the one with the UV lamp, the bulb will need to be changed about once a year, the same as ours.