Our heating and cooling forced air system initially emits an odor after sitting
idle for a couple of days. The house is 40 years old; furnace and AC replaced 10
years ago. If the AC is off for a day or two it has a “musty” smell when first
turned on requiring all the windows to be opened for about half an hour to
clear. We cleaned all the registers, removed and cleaned the blower, put bleach
down the drain line, removed the de-humidifier and vacuumed out the plenum. The
insides are dry, drip pan is dry and clean and the coil looks relatively clean.
We also replaced the electronic air filter with a dry paper type. The smell is
emitted from each register yet we could see no evidence of any mold growth and
could not smell any unusual odor when the furnace was first opened. The smell
cannot be detected if the AC is cycled ever day. We read the pros and cons about
the benefits of duct cleaning and don’t know if that would help or not? Any
recommendations would be greatly appreciated.
It is called DSS in the trade. Dirty Sock Syndrome.
First, its in your evap coil, not in your ducts, unless you have a kid that
pissed into them, or threw his dirty towls into a duct.
Second, unless you have true hard metal ducts, not insulated on the inside,
you can clean your ducts, and then you can replace them.....since anything
else will be destroyed...
Your evap coil will need to probably be pulled, and foamed with the proper
cleaner, flushed and re-installed....but we cant see it from here.
Look it up on Google..
Our kids are all adults and long gone so it's not urine or dirty laundry. The
ducts are hard metal without any coating in or out. However, it would require a
professional to pull the coil as the two copper lines pass through holes in the
plenum and will need to be unsoldered in order to remove the front furnace cover
and get the coil out. And we are not experienced in the techniques required for
that job. We can reach the coil through the humidifier opening in the plenum
above the coil. The coil is an "A" frame and we could apply a cleaner and flush
it in the furnace but that would certainly flood the basement. Guess our next
step is to contact the installer. We suppose it would cost as much to clean the
coil as it would to replace it?
We did a Google search and found that duct cleaning was not highly recommended.
I'll do a Dirty Sock Syndrome search now. Thanks much for your replies.
Thanks hvacrmedic for your input. That was one of the first things we did. We
disassembled the humidifier, tossed the evaporator unit and cleaned out the
housing as best as possible. The heating/AC system is currently running with an
empty humidifier housing and the water supply has been turned off. I apologize
for not mentioning this earlier in my original post but I just forgot about it.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.