I guess the thing that puzzles me the most is that the old unit worked fine for so many years and as soon as new unit is installed "presto" we have a horrible odor for the last 5 years everytime we switch from heat to air or switch from air to heat. Through the middle of summer or middle of winter there is no problem. Thanks
A lil extra info
First i want to say the theory about recycled aluminum being the cause is nonsense. Aluminum, whether recycled or virgin, is used on hvac evap coils due to it heat transfer abilities and it's ability to shed water without beads forming. this is neccesary to reduce backpressure of the airflow across the coil and to ensure more condensate makes it to the drain rather than being blown back into the supply duct. Becuase of this key aspect of aluminums role one would logically assume that regardless of whether the aluminum was recycled or virgin the equipment manufacturers would use and alloy with specific surface properties to serve that purpose, meaning there would be no difference in the end product simply because the original raw material was procured from a different source.
Next i would add that current system designs do contribute to the intensity of the DSS but are not by any means the source. Over the past decades as efficiency minimums have increased coils have gotten not only larger but the aluminum fins have become more tightly packed together creating smaller crevasses ideal for harboring contaminants. In addition, when once systems were designed for 400 cfm per ton airflow now most are designed for 350 cfm per ton to achieve efficiency and this allows for a lower airflow velocity through the coil which could potentially make it easier for airborn contaminants to land on the coil and stick. While these may seem like smoking gun details i would remind everyone that they are neccessary to meet ARI standards and are by no means the source of the underlying issue.
Before commenting on the issue at hand, DSS, i want to state that dirty sock syndrome can result from any source of bacteria, mold or fungus whether it is be a new pet, leaking ducts, spores picked up on a weekend hike, an improperly installed drain line or a different strain of athleets foot picked up at the gym. It simply results from the culmanation of various circumstances that lead to contamination of the evap coil. That being said, it's impossible to say there is a 100% effective way to rid your home of DSS, there are only ways to treat and hopefully prevent first of which is annual cleaning (reccomended by most manufacturers any way).
If a cleaning is done, whatever chemical is used the cleaning must be thorough and the chemical remain in contact with the coil long enough to ensure a positive effect. UV Lights?...only treat surfaces within a few inches of the light so are useless for the inner surfaces of a coil. Good filtration?...excellent preventative measure but not always viable because better filters must be larger or they could restrict airflow reducing system capacity and result in premature failure of a compressor.
It's true that coils coated with a antimicrobial compound are extremely effective but any treatment will loose it's effectiveness with time so even a treated coil is not a permanent solution.
There is no one answer here so do your homework and check facts not just forums.
Nice Post what is your back ground?
Originally Posted by cb975
I've been in HVAC distribution and support for 11 years now. For the past 5 i have worked in a tech support role assisting contractors with various issues in the feild as well as acting as a go between from the contractors we serve to the engineers who design the equipment well sell and support. For the particular brand i support DSS has never been considered an issue with the equipment but they have been accomodating when we make efforts to help our contractors out of a tight spot when they have a DSS problem. Over the years we have encountered the issue several times and had dealers that would change coils and even switch from one brand to another changing the entire system. Sometimes they are lucky enough that the source of the DSS was taken care of in the process but most times it was not. I hope that the small amount of information i provided will be helpfull.
I, too have this DSS problem, and I have a new Trane heat pump that was installed in June of 2009. I first noticed the problem on a mild summer day when I switched the fan from "auto" to "circ" to have the cool air circulated while sleeping. When the AC came on later that morning, I noticed an awful stench in the house. At first I thought it was my dog who had just been outside, but it wasn't her. The smell was very pungent and smelled like a wet dog that had been left to dry outside in the hot sun.
I noticed the smell coming from the registers in the house. I quickly turned the system off thinking something had burned up, maybe a motor or something in the AHU. I went in the attic and the smell wasn't up there, so I resumed cooling. After about an hour and a half the smell stopped coming from the registers, but it still lingered in the house and on my clothes.
Since then I have not turned the fan to "on" or "circ" in the summertime and the smell had not come back.
Fastforward to the fall.
When we had our first cool nights here in TN, i switched the tstat to "auto" and left the fan on "auto" as well. When the heatpump first came on to heat the house, the smell was back. I do not know if the aux heat strips came on to defrost because I was asleep and didn't think to look, but the smell was enough to wake me and the wife up.
Now that we are in heating season, I leave the tstat on "heat" and the smell does not show up. Now if I know the temps will get warm, I will switch the stat to "auto" before I leave just to have a cool house when I get home from work. And when I get home from work I can tell the AC has come on simply by smelling the air first thing when I walk through the door.
I have been doing a lot of reading about this and the consensus is that mold/bacteria is the culprit. I am going to have my season PM done soon and pick the tech's brain a bit to see what he thinks.
If we are able to come up with a solution, I will be sure to post here.
Amana / DSS
It appears we have also been hit with the DSS issue on our two brand new heat pump systems. We have a hybrid system on the first floor. I tried to run the gas furnace for a day or two (forcing the TH to emergency heat) -> no luck.
Our HVAC contractor started to call Amana -> their initial standard reply was to use a cleaning solution or using a UV light.
Does anyone has any experience dealing with Amana and getting new coated coils under warranty?
Thanks in advance for any suggestion.
A word of caution: If you end up with a coated coil don't also put in a UV light that radiates the coil. The UV can deteriorate some coatings releasing harmful gases. If you put a UV light anywhere else in your system make sure it doesn't shine on flex duct. Plastic and UV lights dont play well together.
I have heard that the RGF Guardian air purifier will kill the DDS odor. www.rgf.com
Thanks a lot for the information. My question is if someone knows what kind of coating is used by Trane / Amana.... to address the issue.
Originally Posted by TalkingHead
I know the coating used to protect the coil strips from corrosion seems to be the standard. But then I have read about athalene II / REP-60 / agION .....
Thanks - Didier.
Thanks for the recommendation. I am trying to determine if this unit produces Ozone?
Originally Posted by AirBoy4u
this cracks me up everytime i read it ROFLMAO
Originally Posted by jnixon550
aluminum is a very porous metal as well.
do a google serch for "how porous is aluminum metal" and you will find a lot of stuides, research and technics that have been done and found to help prevent and keep this metal from being so porous. But it is still an issue when you're talking about microscopic sized bacteria and places for it to attach to and bond with.
expecially mold. porous is the reason why drywall is so difficult and nearly impossible to "clean" after mold spores have started.
only one way to kill those bacteria, and that's to eliminate the food source of moisture. and that's not going to happen in an air conditioning coil.
during the seasons of in between heating and cooling and during defrost cycles in the winter, the moisture is re-entroduced to the bacteria in the porous metal and the funk begins to pour into your living space.
and we have had great success with UV lights. and as far as just the surface? can you explain why some systems we have had to replace non UV resistant drain pans, because the pans had lines ate in them from where the light shined though the coil???
Another DSS victim
I had a new Heat Pump installed in April of this year. I have the classic DSS symptoms--when the unit goes into defrost.
The dealer has no interest in this problem, saying it's due to environmental conditions. Well, hey, when you have a petri dish for an evaporator coil, any number of ordinary microbes could land there and set up house.
After researching UV lights, coated coils and the like, I am probably going to take the drastic step of having a LP furnace installed and the current air handler ripped out. My wife and son have allergies, and this is unacceptable. You can't imagine how distressing it is for me to hear my son coughing and sneezing and asking for his inhaler morning after morning. I live in eastern Pennsylvania, and this phenomenon was rare but is occurring more and more.
The original system cost 4500 to have installed. The LP replacement will cost about the same. There goes the summer vacation.
What a nightmare!
I have a degree in HVAC technology, and I was a tech rep for Snyder General for a time. This sort of thing didn't happen when heat pumps weren't so efficient--and had higher coil temps and fewer fins/inch on the evaporator coils. As for the recycled aluminum, I have no idea. It sounds plausible, but I've only heard anecdotal stories about it.
I would think moving to a standard furnace would eliminate this problem, since the coil would be out, and the new a/c coil would be downstream of the heat exchanger and thus see much higher temps in the winter. I'm not sure how the crud could migrate to the supply ductwork, given that there's no moisture there to sustain it.
I'm getting bids for a new furnace soon. I may then initiate a civil action against the contractor, but I don't see myself standing much of a chance, since this is a very grey area of HVAC responsibility.
Wish me luck.