Molds are often referred as ‘sneaky little bugger’. They can trickle into your house from the outside environment and mushroom all over the living space. All they need is a bit of moisture and dirt to breed and grow. They are sometimes visible as black patches or whitish streaks or other visible forms. Sometimes they may not be visible at all. Their presence is felt through the diseases they cause to the occupants of the house. These could be breathing troubles, sinus, respiratory inflammation, allergies etc. And the fastest way to spread mold through a building is through a forced-air HVAC system. Molds are difficult to terminate. They are present in the environment. In dry weather they are unable to breed. In moist and humid weather they proliferate very rapidly. Although you cannot terminate mold growth absolutely, you can, of course, control it.

How to detect molds?

It is not an easy job to detect molds. Sometimes you will get visual evidence of mold growth in the ducts in form black patches. A bizarre smell would also emanate from it. There could be weird discoloration at the vents. Also look for signs of moisture or water that is tricking in your ducts. If you find one of these clues you can go straight to re mediating it.

However, mold will not have visible manifestation necessarily. Under such circumstances, if you suspect that mold is growing in your ducts then you can hire a qualified mold tester to check for mold. However, it's important to note that according to the Centers for Disease Control and Prevention (CDCP) there are no standards for what is an acceptable amount of mold, as every home contains some level of mold. According to CDCP, the testers should interpret results based on their findings and gradually set a standard for mold detection.

How to clean up mold in the HVAC ducts?

According to the EPA, the ducts and various components of HVAC should be checked routinely for molds. The mold factory mainly builds up in the drain and condensate pans of the HVAC, if they get bunged. Also make sure that all HVAC ducts and system components such as air handlers, blowers, plenums and the like are free of any moisture.

If in spite of these you feel that these sneaky buggers are breeding nonchalantly without being visible, then it is better to call mold tester. Here is what is generally done to clean molds in HVAC unit and the ducts-

• The cleaner wears protective clothing and N-95 respirator.
• They would first turn off the HVAC. Every entrance to the HVAC system is located. This includes ceiling, floor, and wall registers and the air returns. Each of these entry points is removed to access the ducts.
• They would then replace the porous parts of the unit such as filters, or damp insulation. The wastes are collected in a double-bag or bags made of thick plastic sheets.
• Any standing water will be cleaned with a vacuum cleaner.
• If the ducts and other components of HVAC are infested with mold, mildew and other dirt, then EPA registered chemical solutions are used to remove them.

• In case of mold contamination, the cleaners use bladders. This is to isolate the areas that have been cleaned. These will prevent the newly stirred up molds from spreading to other parts of the system or the building. The area is fogged with an EPA registered disinfectant.
• All the dirt and debris are removed in the end with a HEPA vacuum.

In some of the states a mold tester is different professional than a mold cleaner. The company that inspects for mold may not do the remediation as well. Testing can be expensive. It may cost a few hundred dollars.