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First fall/winter here in NC....Anybody ever experienced an intermittent musty odor coming from their vents with heat on? Just started using heat a few days ago and noticed the odor. Had no odor with air conditioning running all summer...never had a heat pump before. Need an education. Thanks!
Alright here is your issue. During the summer water builds up inside the air handler from either the coils or the A/C set too high during the summer thus pulling in more humid air. Depending on the air handler there be one or two PVC (plastic) pipes coming out of it. One will head out to a drain or straight outside, the other may exist if it is in a crawl space and will only be a few inched long and drip water to the ground as an overflow to the other. Thus the primary one may be clogged and you may have to call an HVAC person to clear the pipe. Look at the outside of the air handler, you may see rust. There are two ways to correct this. Both require opening the panel above the pipes. One way is to vacuum out the collected debris in the holes and blow out the pipe with a garden hose( or air from a external compressor) or the other is to replace the U pipe depending on your compfort level as a DIYr. If not then call HVAC person in the spring for a tune-up (thats when they run their specials).
First fall/winter here in NC....Anybody ever experienced an intermittent musty odor coming from their vents with heat on? Just started using heat a few days ago and noticed the odor. Had no odor with air conditioning running all summer...never had a heat pump before. Need an education. Thanks!
Do a Google search on " "Dirty Sock Syndrom" & "Heat Pump" " and you will come up with a great deal of information regarding the possibilities. One good source is this site which will provide you some information with how to isolate the issue to DSS or some other cause What is the “Dirty Sock Syndrome?” (http://www.foxservice.com/kb/article-8.html - broken link). NeilVA lists another potential cause.
If you have a heat pump you will be using the interior evap coil all year round and that is where the DSS tends to be an issue. You can easily clean evap coils yourself if you're not intimidated by DIY projects, and if you can easily access it. All it takes is a bottle of non-acidic, low sudsing coil cleaner (available at Home Depot and Lowes), and a spray bottle (I use a basic 2 gallon hand pump sprayer also available at HD and Lowes making sure the pump sprayer is very clean with no other residues in it). While you are cleaning the interior evap coil I would also clean the exterior compressor coil as well.
When you clean the interior evap coil you will have the covers off and I would take the time to hand clean the casing interior and out, as well as the primary and secondary drain pans and condensation lines. For the other cleaning you can use Lysol or other household cleaners (use as directed) meant to kill and clean fungus. Make sure the electric to the unit is shut off and you don't get water on the electrical portions, circuit boards, etc.! All you need is a damp rag for cleaning and not a soaking or dripping one.
If you have attic based ductwork and can see any of it from a working platform (use binoculars for farther away parts) also look for ductwork that might be pulling loose and allowing attic air, and possibly other contaminates in. Scan your attic area for signs of moisture intrusion and mold growth. Also look for the potential of insect access as crickets love attics and can also make that nice odor as well. Inside the home take a ladder and pier into your ductwork openings, remove covers if you need to, and look for debris, signs of mold or other contaminates. Make sure you have decent filters in the return air path(s) as required by your system and that they are not dirty and blocked. I've found the $4 3M pleated filters (if your system can take them), swapped out monthly usually work as well as the $20+ specialty HEPA Filters. Although for you I would use the manufacturers recommended filters until you isolate the issue.
Make sure you have decent filters in the return air path(s) as required by your system and that they are not dirty and blocked. I've found the $4 3M pleated filters (if your system can take them), swapped out monthly usually work as well as the $20+ specialty HEPA Filters. Although for you I would use the manufacturers recommended filters until you isolate the issue.
Just use the cheap blue or green filters (2/$1.00) and make sure you religiouly change it once a month. The other ones are good for allergens but makes the handler work harder.
To give you an example of flow differences, our house vacuum died. So we went out and bought another one in the same family at sears. It didnt suck as well as the old one. Took it back and exchanged it. Same problem. Went through the manual and found that they had added two extra filters and changed the bag from paper to cloth. Went back to sears and purchased the paper version of the bags and removed the extra filters. Now it works perfectly and is powerful.
Any honest HVAC person will tell you to buy cheap furnace filters.
I am using those more expensive filters that I have to replace only every 3 months. I kind of makes sense that it could make the handler work harder. but here's my question --- could the inhibited air flow possibly contribute to that sour smell I get coming from vents?
I DID notice that the only time I get that smell is each time the heat pump goes into defrost mode. I smell it for about 10 seconds and then the smell disappears as the air coming out of the vents starts to get warmer. Can anyone provide info on this???
I am using those more expensive filters that I have to replace only every 3 months. I kind of makes sense that it could make the handler work harder. but here's my question --- could the inhibited air flow possibly contribute to that sour smell I get coming from vents?
I DID notice that the only time I get that smell is each time the heat pump goes into defrost mode. I smell it for about 10 seconds and then the smell disappears as the air coming out of the vents starts to get warmer. Can anyone provide info on this???
This is from the article I linked above:
Quote:
What is the “Dirty Sock Syndrome?”
Complaints normally surface when heat pumps go into defrost, or when systems are run in heating for a brief time then switched back into cooling. The bacteria or odor collects and grows on the coil during this heating time and is released all at once when the indoor coil gets cool and damp. Heat pump owners notice the odor when the system goes into defrost, usually when the outdoor temperature dips below 40 degrees.
There are other possible causes and potentially an air flow restriction might play a part in the smell. However, I would consider either try cleaning the coils or having a HVAC Tech in to clean and check them. For DSS they will generally use a specialized antibacterial cleaner that is will, in most cases, clean and coat the coils to help ensure the bacteria does not recur.
I just read a number of replies to DSS on other websites. Shocking as to how many have this problem. Many have said the antibacterial coil cleaners work for a short period of time....sometimes a few days later the odor returns. Others have purchased expensive UV lights only to have those fail. Some have actually gone the distance and replaced the coil with a special coating that prevents bacterial growth and found success with that. Any idea of how much a replacement coil costs? I am not familiar with the cost of heat pump related repairs....
I just read a number of replies to DSS on other websites. Shocking as to how many have this problem. Many have said the antibacterial coil cleaners work for a short period of time....sometimes a few days later the odor returns. Others have purchased expensive UV lights only to have those fail. Some have actually gone the distance and replaced the coil with a special coating that prevents bacterial growth and found success with that. Any idea of how much a replacement coil costs? I am not familiar with the cost of heat pump related repairs....
A replacement coil cost would depend on your unit's make and model. If you know that you can Google it and the words "price", "evaporative coil", and get an idea. However the cost of a same type coil might well be passed by all of the other associated costs such as labor, refrigerant recovery (by law), recharging with new refrigerant, and any other necessary activities at the time.
There have been attempts at removing the coils and coating them with a special agent/sealer that can seal the micro pits on the coils surface. This was theoretically suppose to help prevent microorganisms from settling on the surface in those pits and growing. The problem with this is that it is an additional large cost and your unit will be out of commission, or running on backup heat strips, until the coil comes back. Replacing the coil with a like coil. or even this specially coated coil, has not proven to be an effective and widespread correction for the problem.
Your best bet is to try the coil and case cleaning method first as it is a great deal less than any other action and might solve your case/issue. A simple cleaning has solved many cases of DSS, as well as other issues that can cause the odor. When you bring the HVAC Tech in they can also review your entire system to ensure there is not another cause of the odor.
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