20 | COLUMN—November/December 2017
Insist that the company you hire to do this work also in-
spects your furnace and cleans it as needed, including the
blower, blower cabinet and air conditioning coil (if present).
The cooling equipment may have to be dismantled for the
job to be done properly. Containment (to isolate the work
space) should be set up to prevent the spread of potentially
allergenic dust. (Duct cleaning by professionals who only
use a vacuum is inadequate; brushes must be used.)
If you have duct board or flexible ducts and they are very
soiled, consider replacing them, as these kinds of ducts
cannot be adequately cleaned.
Panned bays (using a building cavity as a return ple-
num — https://www.nachi.org/building-cavities-supply-
return-ducts.htm) are very difficult to keep clean, and can
often lead to leakage of allergenic basement dust into the
duct system.
How can this panned bay be cleaned?
May Indoor Air Investigations LLC
If you have panned bays in your home, consider having
them opened up, cleaned and lined with smooth material,
and made airtight.
Mechanical equipment in the attic: Duct cleaning also offers
an opportunity to have ducts that may be located in your
Dry, cool fall air is refreshing after hot, humid summer
weather. It's a good time of year to open up windows on a
temperate afternoon to air out the house, but many of us
are starting to turn on the heat. Winter is around the corner,
so it's time to start thinking about the condition of your heat-
ing equipment.
Hot-Air Heat
Keep the system clean: If young children are living in the
house, you might be surprised at what you find in the
"boots" (the metal area beneath each grille). I've seen
Cheerios and toys in boots. If you have a pet (or if a pre-
vious owner did), the return duct may even be packed
full of pet hair and dander.
Vacuum the supply and return grilles. Remove any floor
grilles so you can vacuum out the boots.
Use a vacuum with HEPA filtra on (with a bag, please)
for all household cleaning.
Have your furnace and ducts professionally assessed to
see if cleaning is needed.
Return duct full of dust: note dust patterns caused by airflow
Envirotech Clean Air; www.breatheasier.com
Clean the Mechanicals ©2017 Jeffrey C. May