Mold is organic and is an important part of our our world. It is everywhere we go whether indoors or outdoors. It plays a very important part in our world by breaking down dead organic matter such as wood, paper, grass cuttings, leaves, decayed trees, plant cuttings and other things of nature. It does not belong indoors and should be limited. If given a chance, mold likes the drywall in your home also. You ask why, drywall has paper on both sides and is conducive to grow mold when moisture invades during a water leak or flood. It grows in your A/C Unit because there is a wet environment by the A/C Coils. The A/C Coils are a vital part of your air conditioning system. This is the area which takes water out of the air in your home. If it is not kept clean, your system will not work efficiently.
Poor quality filters can cause your A/C System to fail over time. We have seen this in many homes that were inspected and the homeowner didn't even know it existed. The extra stress placed on your system by blocked airflow due to dirt can cause your system to fail and grow mold on the coils. This stress on the A/C System can cause your blower motor to burn out and not cool the house efficiently.
As the A/C cools your home, it dehumidifies the air. The dehumidified water then drains off of the A/C Coils into the A/C drain pan and then runs out the A/C Drain line. There is always slime mold in your A/C Drain Pan. This is what causes a water backup in the unit. The mold and algae builds up and then finally stops up the A/C drain line. Some individuals put special antimicrobial tablets in the A/C Drain Pan to help suppress this growth. Special care must be used when using these tablets, some people are allergic to their ingredients and must avoid using them. The drain line should be monitored on a regular basis. Minimum checkup time is every 6 months. Look for the exterior location of the A/C drain line to see if it is draining properly.
Maintenance is important regarding your A/C or you can guarantee there will be a water backup or a leak if you do not. Have you A/C Contractor install an auto cutoff switch before the A/C Unit starts to leak. This is a good precaution to prevent a flood from you A/C Unit. If it starts to back up, call a proficient A/C Contractor that understands the importance of Indoor Air Quality. If you are not handy, consult with your A/C Contractor regarding a Maintenance Contract to take care of your A/C Unit. A/C leaks are the number one reason why mold grows in the A/C Closet. Sometimes we see it go undetected for 6 months and cause substantial damage. One of our clients was forced to move out while half of their 1st Floor drywall was removed and remediated for mold. It is not a good picture. Remember, maintain your A/C Unit and it will cool you for a long time.
Keeping the system clean is the filter's job. 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 like mold growing on the coils. The cost of having a service call to clean or change the coils in your A/C System would pay for the high quality filters of at least 5 years. Using a fiberglass filter gives you minimal protection for your A/C System. The factory filter also gives you minimal protection from the elements in the air.
Our general rule is: Hold the filter up; if you an see through the filter, it only gives minimal protection from allergens, dirt, dander and mold spores. Our minimum recommended filter is a Merv 7 Pleated Filter. Look at the product label and find the MERV rating. They are available in Home Depot, Lowe's or your local hardware. As always, check with your A/C Units manufacturer to see if it the filter will void their warranty. This can be caused by using some of the too efficient pleated filters which can cause high arrestance of a Merv Rating. This high arrestance will cause dirt to bypass the filter and clog up the coils. We see this all the time. Remember, the filter company's only want to sell their filters and make money. I personally use Home Depot's “NaturalAire” Standard which is rated at Merv 8. II'm happy with the results of this filter. The only difference is, I change the filter once a month and recommend everyone to change your filter once a month to minimize exposure to allergens.
The Merv Rating stands for: Minimum Efficiency Reporting Value. It is a test by the American Society of Heating, Refrigeration and Air Conditioning Engineers. (ASHRAE) The number is so the consumer can compare filters. The higher the number, the more efficient it is.
Tips on A/C Maintenance
1. Most A/C Systems over 5 years old need to be serviced on an annual basis.
2. Routine maintenance can double the life of your unit and save you money.
3. Health risks can be dramatically reduced by proper system maintenance.
4. Energy costs will be lower by maintaining the A/C Unit.
5. Ducts should be inspected every 3 to 5 years for possible deterioration, contamination and leaks.