EPA Form EPA-4U24, October 1997

NYC 9/11 Public Portal Document

How to Prevent Duct humidifier strictly as recommended Contamination by the manufacturer.

hither or not you decide to have To prevent ducts from becoming wet:

cleaned, following a good preventive Moisture should not be present in ducts. maintenance program is essential to Controlling moisture is the most effec­ minimize duct contamination. tive way to prevent biological growth in air ducts. Moisture can enter the duct To prevent dirt from entering the sys­ system through leaks or if the system tem: has been improperly installed or ser­ viced. Research suggests that conden­ ✓ Use the highest efficiency air filter sation (which occurs when a surface recommended by the manufacturer temperature is lower than the dew point of your heating and cooling system. temperature of the surrounding air) on or near cooling coils of air conditioning / Change filters regularly. units is a major factor in moisture con­ tamination of the system. The presence Z If your filters become clogged, of condensation or high relative humidi­ change them more frequently. ty is an important indicator of the poten­ tial for mold growth on any type of duct. Z Be sure you do not have any Controlling moisture can often be diffi­ missing filters and that air cannot cult, but here are some steps you can bypass filters through gaps around take: the filter holder. Z Promptly and properly repair any Z When having your heating and leaks or water damage. cooling system maintained or checked for other reasons, be sure to Z Pay particular attention to cool­ ask the service provider to clean ing coils, which are designed to cooling coils and drain pans. remove water from the air and can be a major source of moisture contami­ Z During construction or renova­ nation of the system that can lead to tion work that produces dust in your mold growth. Make sure the conden­ home, seal off supply and return reg­ sate pan drains properly. The pres­ isters and do not operate the heating ence of substantial standing water and cooling system until after clean­ and/or debris indicates a problem ing up the dust. requiring immediate attention. Check any insulation near cooling Z Remove dust and vacuum your coils for wet spots. home regularly. (Use a high efficien­ cy vacuum (HEPA) cleaner or the Z Make sure ducts are properly highest efficiency filter bags your sealed and insulated in ail non-air- vacuum cleaner can take. conditioned spaces (e.g., attics and Vacuuming can increase the amount crawl spaces). This will help to prevent of dust in the air during and after moisture due to condensation from vacuuming as well as in your ducts). entering the system and is important to make the system work as intended. To Z If your heating system includes prevent water condensation, the heating in-duct humidification equipment, be and cooling system must be properly sure to operate and maintain the insulated.

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