If the one noticeable spot is where the wall [or ceiling or floor] is white.......first.....take a pair of needle nose pliers and bend each louver of the register to a straight outward position [as they all come brand new with a slant to each side]....so the register is shooting all supply air straight outward. If its a round register [in ceiling].....no help there. You also should always burn soy or beeswax candles.
yes get a good company and pay the price, I found so much dust and dirt and wood and paint chips and bugs and even bottle caps in my ductwork. I hired a major plumbing company who cleaned ductwork and i will say they did an excellent job cleaning my vent. they did miss one point in my ductwork because i still started to see dust all over my furniture and i realized that my retunduct work that was connected with a piece of sheet metal beam which was 16" across , the contractor that built my condo used a 16" wide sheet of sheet metal to connect the vent system to my return for the air to return back into my condo. The contractor should have built a 8" x16" square duct by 6 feet long to connect my intake to my return instead of using a sheet of sheet metal 16" wide by using two 3' sections by 16 inches wide. That was a shor cut which caused a major problem fir me.
The short answer is yes, duct cleaning, done right by a reputable company will help with the smell. It is likely though the smell is coming from another source, ie the crawl space. It could also be that another rodent is dead in the duct work. A visual inspection would be in order to check for any breach in the duct system. A duct pressure test would be able to tell you how much air is leaking from the system over all. A hole large enough for an animal to enter would loses a great deal of air, over 300 CFM. It would be worth looking into having this test done and it should cost around $200. Cleaning the air handler and evaporator coil will greatly improve the performance of the air conditioner. Dirt and dust on the evaporator acts as insulation and reduces the amount of cooling done be the coil. Any quality duct cleaning should include cleaning the air handler and coil, and the tech should allow you to watch him perform the work as it is done.
Heating, ventilation, and air conditioning (HVAC) systems have been shown to act as a collection source for a variety of contaminants that have the potential to affect health, such as mold, fungi, bacteria, and very small particles of dust. The removal of such contaminants from the HVAC system and home should be considered as one component in an overall plan to improve indoor air quality.
Vinick calls air duct cleaning an essential part of home maintenance, akin to mopping and vacuuming. "It’s like changing the oil in your car,” he says. “If you don’t change the oil, you’re going to have a problem. When your components are loaded up with debris, the system has to work harder. When you remove that debris, you get energy consumption savings.”
Quality and price should come hand in hand, a too-good-to-be-true price for an efficient air duct cleaning will not give you the quality that you wanted. To make sure you are getting your money’s worth, check reviews of air duct cleaning companies, certifications from industry since this work requires continuous learning due to new techniques and research breakthrough from time to time. My mom is located in Arizona and they trust J&M Restoration air duct cleaning company, they have an A+ BBB rating, they used EPA approved sanitizing agents, their technicians are NADCA certified, and the company is certified by the Institute of Inspection, cleaning and Restoration. Make sure to shop around and get written estimates first.
I recently did some remodeling and figured I’d get the air ducts cleaned in our 12 year old home. After obtaining 4 estimates between $572 and a whopping $3,075 for 25 vents and 2 air handlers, I knew I was in for a ride. I read through this blog and decided to use a $79 inspection camera I just found online (Home Depot) to take a look at all my ducts by removing the ceiling grilles first and then try to get into the ducts from the other end. From what I have just learned here, I believe that will take care of my “concerns”.
Some research suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and heat exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance cost savings. However, little evidence exists that cleaning only the ducts will improve the efficiency of the system.