Dirty Sock Syndrome

I can’t think of many things that smell worse than a wet, dirty sock, Ok, maybe I can. Let’s see-a day-old diaper, the rat that died under the refrigerator, my aunt Mamie on a humid summer day… Anyway, a wet, dirty sock is pretty bad. And it’s worse if it’s being wafted through the duct system of your home, every time you run your air conditioning or heat. Ladies and gentlemen, may I introduce you to “Dirty Socks Syndrome”, hereafter referred to as DSS, to save me the time of typing it again.. All of a sudden, I've been getting a rash of emails from readers reporting that they have a stinky HVAC (heating, ventilation, and air conditioning) system. DSS might just be the culprit!

I was surprised when I recently discovered the phenomenon of DSS. After eliminating several of my own theories, I called Eric Nichols at Daisy Mountain AC, and he pointed me in the right direction. Just when I thought I knew everything, up pops yet another problem that requires me to do yet more reading and research! This research led me to the Residential Duct Systems Manual “D”, brought to you by your good friends at the Air Conditioning Contractors Association of America. (Actually, Eric faxed me the info but you don't have to know that) According to what I read, there isn't really a clear consensus on what causes this phenomenon. Some researchers contend that it is the result of biological contaminants that get sucked through your HVAC system. These microorganisms stick to the evaporator coil. Now here’s where things get a little sketchy. Many researchers say that DSS only occurs with electric heat! The problem with that is that the people writing me all have gas heat, AND were experiencing the stinkies in the summer, when the air conditioning was being used. So now I have to add my own wild and unconfirmed speculation. So here goes:

If your evaporator coil (you have at least one in your attic, trust me) gets dirty, then these microorganisms can gain a foothold. These guys already exist in the air and unless you have a better than average filtration system, it's just a matter of time before they coat the coil. Leaky duct work and infrequent filter changes will accelerate the contamination process. During monsoon season, we get a lot of humidity. The moisture works as plant food for these microorganisms. The nice warm environment that a summer attic provides, serves as a Petri dish. The only thing left is for you to turn on the AC. Now that nasty, stinky, mess gets wafted throughout your home. It's kind of like taking a teenager's dirty laundry hamper and attaching a blow dryer!

So, what do you do? The first thing is to have an HVAC professional come out and check it out. Do your due diligence so you don't get a fly-by-nighter trying to sell you a bunch of unnecessary add ons. A good evaporator coil cleaning should do the trick. If the guy recommends duct cleaning, get at least one other unbiased opinion. If the stink tends to come back, you might have leaky ducting. I really want to stress the importance of using a good company. If not, you could get taken to the cleaners!

A long term option might be a device that employs a broad spectrum high intensity UV light to kill the microorganisms. UV light has long been used in the food, air, and water industries as a method of killing nasty germs and bacteria. These guys can cost $700 or more, so (for the third time!) do your homework! And before you go and spend a bunch of money, make sure it's not something that crawled under the fridge!