Mold is organic and is an important part of our world. It is everywhere we go, whether indoors or outdoors. It plays a huge role in our world by breaking down dead organic matter like wood, paper, grass clippings, leaves, decaying trees, plant clippings, and other things from nature. It does not belong inside and should be limited. Given the chance, mold likes the drywall in your home, too. You ask why, drywall has paper on both sides and leads to mold growth when moisture invades during a water leak or flood. It grows in your A/C unit because there is a humid environment in the A/C coils. Air conditioning coils are a vital part of your air conditioning system. This is the area that draws water from the air in your home. If it is not kept clean, your system will not work efficiently.
Poor quality filters can cause your air conditioning system to fail over time. We have seen this in many homes that were inspected and the owner did not even know it existed. The added stress placed on your system by blocked airflow due to dirt can cause your system to fail and mold to grow on the coils. This strain on the air conditioning system can cause the fan motor to burn out and not cool the house efficiently.
As the air conditioner cools your home, it dehumidifies the air. The dehumidified water then drains from the A/C coils into the A/C drain pan and then out the A/C drain line. There is always mold in the drain pan of your air conditioner. This is what causes a buildup of water in the unit. Mold and algae build up and eventually stop the A/C drain line. Some people put special antimicrobial tablets in the drain pan of their air conditioner to help suppress this growth. Special care should be taken when using these tablets, some people are allergic to their ingredients and should avoid using them. The drain line must be regularly monitored. The minimum control time is every 6 months. Look for the outside location of the A/C drain line to see if it is draining properly.
Maintenance is important when it comes to your air conditioner or you can guarantee that there will be a buildup of water or a leak if you don’t. Ask your air conditioning contractor to install an automatic kill switch before the air conditioning unit starts to leak. This is a good precaution to prevent your AC unit from flooding. If it starts to back up, call a competent air conditioning contractor who understands the importance of indoor air quality. If it’s not on hand, check with your AC contractor about a maintenance contract to take care of your AC unit. A/C leaks are the number one reason mold grows in your A/C closet. Sometimes we see it go undetected for 6 months and cause substantial damage. One of our clients was forced to move while he removed half of the first floor drywall and remediated mold. It’s not a good image. Remember, maintain your AC unit and it will cool you down for a long time.
Keeping the system clean is the job of the filter. The average filter that comes with the unit is not a good quality filter. It is a typical factory filter. Using poor quality filters can cause results such as mold growth on the coils. The cost of having a service call to clean or change the coils in your air conditioning system would pay for high quality filters for at least 5 years. Using a fiberglass filter provides minimal protection for your air conditioning system. The factory filter also gives you minimal protection from the elements in the air.
Our general rule of thumb is: Hold the filter up; If you see through the filter, it provides only minimal protection from allergens, dirt, dander, and mold spores. Our recommended minimum filter is a Merv 7 pleated filter. Look on the product label and find the MERV rating. They are available at Home Depot, Lowe’s, or your local hardware store. As always, check with the manufacturer of your air conditioning units to see if the filter will void your warranty. This may be due to the use of some of the overly efficient pleated filters which can cause a high stop of a Merv rating. This high hold will cause dirt to be bypassed from the filter and clog the coils. We see this all the time. Remember, the filter company just wants to sell their filters and make money. I personally use Home Depot’s “NaturalAire” standard, which is rated at Merv 8. I am happy with the results of this filter. The only difference is that I change the filter once a month and I recommend everyone change their filter once a month to minimize allergen exposure.
The Merv rating stands for: Minimum Efficiency Reporting Value. It is a test of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. (ASHRAE) The number is for the consumer to compare filters. The higher the number, the more efficient it is.
Tips on air conditioning maintenance
1. Most A/C systems older than 5 years need maintenance annually.
2. Routine maintenance can double the life of your unit and save you money.
3. Health risks can be drastically reduced by proper system maintenance.
4. Energy costs will be lower by maintaining the air conditioning unit.
5. Ductwork should be inspected every 3-5 years for possible deterioration, contamination, and leaks.
