cleaning wrx a/c coil?

[james]

How can I access and clean the air conditioner's cooling coils in a 2002
wrx?
It's not summer yet, but each summer I get an odor from using the a/c. Some
people say cleaning the coils with anti mold cleaners would help.

I understand mold needs water and food. What food could they possibly find
on the a/c coil? Copper?

 

[mulder]

How can I access and clean the air conditioner's cooling coils in a 2002
wrx?
It's not summer yet, but each summer I get an odor from using the a/c. Some
people say cleaning the coils with anti mold cleaners would help.

I understand mold needs water and food. What food could they possibly find
on the a/c coil? Copper?

What you are referring to is not the "coils" but the evaporator core
inside the HVAC housing behind the dash. The mold builds up because of
the standing water left in there after the AC is used and shut down,
even though there is a drain some water will always be left behind and
that promotes the growth of mold and mildew over time.
Things you can do to reduce this problem include checking the drain to
be sure it is clear and removing any clogs (when the AC is running,
you should see water dripping under the car by the front passenger
area, if you don't the drain may be clogged. Look under the passenger
side dash for a rubber hose attached to the housing and if necessary
disconnect that hose and snake or blow it out). Also the AC should be
run in the "fresh air" mode as much as possible, use of the
"recirculate" mode will promote more mold growth. When nearing your
destination, turn off the AC at least a few blocks before you stop and
park but leave the fan running, this will allow most of the residual
water to drain out.
Once mold has formed and is creating odors, it can be treated by
spraying a disinfectant into the HVAC intake with the vent fan running
(AC compressor should be off at this time). Depending on how bad the
mold is, repeated treatments may be necessary. You can use regular
Lysol, or get one of the specific products made for this purpose at a
dealer or parts store. The spray can go in through the outside vents
at the base of the windshield, or for more direct access to the
evaporator intake you can remove the glovebox and open the door where
the optional cabin filter goes, and spray directly into the blower
fan. In fact if you do have a cabin filter installed it is best to
remove it when doing this treatment.

 

[mulder]

What you are referring to is not the "coils" but the evaporator core
inside the HVAC housing behind the dash. The mold builds up because of
the standing water left in there after the AC is used and shut down,
even though there is a drain some water will always be left behind and
that promotes the growth of mold and mildew over time.
Things you can do to reduce this problem include checking the drain to
be sure it is clear and removing any clogs (when the AC is running,
you should see water dripping under the car by the front passenger
area, if you don't the drain may be clogged. Look under the passenger
side dash for a rubber hose attached to the housing and if necessary
disconnect that hose and snake or blow it out). Also the AC should be
run in the "fresh air" mode as much as possible, use of the
"recirculate" mode will promote more mold growth. When nearing your
destination, turn off the AC at least a few blocks before you stop and
park but leave the fan running, this will allow most of the residual
water to drain out.
Once mold has formed and is creating odors, it can be treated by
spraying a disinfectant into the HVAC intake with the vent fan running
(AC compressor should be off at this time). Depending on how bad the
mold is, repeated treatments may be necessary. You can use regular
Lysol, or get one of the specific products made for this purpose at a
dealer or parts store. The spray can go in through the outside vents
at the base of the windshield, or for more direct access to the
evaporator intake you can remove the glovebox and open the door where
the optional cabin filter goes, and spray directly into the blower
fan. In fact if you do have a cabin filter installed it is best to
remove it when doing this treatment.

I should also add that if you do have the cabin filter and it hasn't
been changed in a long time, the filter itself can be the source of
odors not to mention restricted airflow if it's really dirty. If you
aren't sure whether you have one or not, definitely go in there and
check. As I mentioned above it's behind the glovebox (9 screws to
remove plus one little plastic screw/clip thing), once that's out
you'll see the trap door behind which the filter resides. If there is
nothing in that compartment you don't have one but you can always put
one in (check parts stores and Ebay for cheaper alternatives to the
$40 dealer ones). If there is a filter pull it out and inspect it, if
it's nasty get rid of it and get a new one.