What Is That Smell? How To Identify Odors Within Your Central Air Conditioning System And How To Eliminate Them


As spring fades away, people all over the United States are switching on their home's central air conditioning systems. Unfortunately, some of those individuals are going to experience an unpleasant surprise when their system turns on and blows out a bad odor. It's not unusual to find a home where the air conditioning is churning out obnoxious smells, and the problem can be so bad in some homes that it forces residents to leave their systems turned-off. Below is more information on the causes of odor in the air conditioning system and what you can do to alleviate the problem:

Some common odors and their causes

Several kinds of air conditioning odors can cause problems for homeowners, and each one has its own unique smell to help locate the problem. Here is a list of common smells and their causes:

  • Mold or mildew smell – this is probably the most commonly-experienced odor due to the favorable conditions that often exist within a central air conditioning system. This smell can be described as "earthy" or even resembling foot odor. Excess moisture in the form of dampness inside ducts, wet filters and backed-up condensate drains are all possible causes.
  • Rotten egg smell – the smell of rotten eggs can be caused by more than one thing, but the presence of a dead animal inside the system is a likely cause. In addition, sewer gas infiltration can produce a similar odor; sewer gas can be dangerous in high concentrations, so this is definitely an odor to take seriously.
  • Smoky or burned smell – electrical problems, such as short circuits, can create a smell that is reminiscent of gun powder. Obviously, electrical malfunctions are potentially dangerous and can cause house fires, so don't hesitate to take action if you catch a whiff of this particular odor.

Addressing the problems

For odors that have their origin in mold or mildew growth, the first goal is to eliminate sources of moisture in your central air conditioning system. Here are some specific measures you can take to dry it out:

Change the air filters often

The return air vent filters in your air conditioning system are subject to collecting moisture and growing mold or mildew. That's why your filters should be changed frequently during the periods of highest use; once per month is the minimum recommended interval, and more often is better. Also, use spun glass filters whenever possible; they are not only the lowest cost filters available, they also allow maximum air flow through the medium. High air flow helps keep the filter dry.

Unclog blocked condensation drainage lines

Your air conditioner's evaporator both cools and dries the warm, humid air that flows through it. The water removed from the air is collected and drained from the unit via a condensation drainage line. This line is a small-diameter PVC pipe routed through the exterior wall of your home where it drains out on to the ground.

If the line becomes clogged with slime or other material, then water will back up and stagnate. You can clear blocked lines using ordinary household bleach; most lines have an access point for adding bleach or cleaning with a pipe-cleaning brush. If your drainage line does not provide access, then you can cut the line in half using a tubing cutter and insert a PVC tee fitting for access in the future. Simply pour a cup of bleach into the pipe and allow it to work through the clog.

Keep dry air moving

Another way to prevent mold and mildew is to keep dry air moving inside the system. During periods when the air conditioner is shut down, moisture can become trapped inside the ducts, filters and related components. If your central air conditioning system serves dual-duty as your home's heating system, then you should occasionally run the heater during mild weather to dry out the duct work and other interior spaces.

If you suspect that the odor is caused by a dead animal, sewer gas, or an electrical problem, then you will need to contact a qualified air conditioning professional for assistance. They will be able to inspect the inside of the duct work to locate and remove animal carcasses. In addition, they can identify if there is a dangerous tie-in to leaking gases. Only a professional can thoroughly inspect the system's electrical components to see if a failure has occurred and repair it before a dangerous fire erupts.

You can check out the sites of local HVAC companies to learn more about air conditioning repairs. 


25 March 2015

Building our Guest House Was a Great Decision

For years, my wife and I debated on what we wanted to do with all of the spare land in the back of our house. We were lucky enough to buy a house on an extra-large lot for a great deal, but the land was "going to waste" for quite a while. One day, we finally decided to have a guest house built on it, and now that the house is finished, we wish we had built it long ago. We are now renting it out for some extra income, and it is helping us save for retirement. I have always been fascinated by construction, so I enjoyed watching the professionals build the guest house and learned a lot during the process. I decided to fill some free time by blogging about the experience and sharing some construction info I learned during the process. Come back soon!