Living in the California desert has presented major problems with
air quality much of the year.  The amount of dust is amazing and
the humidity required frequent adjustments of the Duo-Art springs.
The softer woods used in the Ampico valves and regulators do not
fare well, while the hardwood in the Duo-Art does much better.
While the evaporative cooler is excellent at raising the humidity,
it brings in dust.

Running three electrostatic air filters in different rooms helps
somewhat, but the ozone level sometimes raises to the level that it
can be smelled.  The fresh smell of ozone is pleasant.  Reducing the
voltage to one unit has largely eliminated the odor.  The manufacturer
told me that the carbon filter should be changed frequently and will
eliminate the ozone.  I have doubts.

Curiously, there is little attention paid to humidity control here
in the desert.  Heating and air conditioning firms do not install
humidifiers.  One firm installed a few mist systems in furnace ducts
but stopped.  They did not disclose the reason for stopping.

An air monitoring facility was moved to a new building near a freeway
ramp.  They noticed that rubber bands were short lived, which led to
an investigation.  The freeway was putting enough bad air into their
building that it caused the problem.  The bottom line in the article
was "notice how fast your stretched rubber bands last."  (I've long
since forgotten the source but I read Scientific American magazine).
My next quest is to seek out the Air-o-Swiss mentioned by Paddy
Handscome.

Bill Chapman - in sunny Palm Springs area, 80 degrees & breezes