How do I clean mold from my AC coils?

Cleaning mold from AC coils requires careful attention to safety and proper technique, as improper cleaning can spread spores or damage the coils. While minor surface cleaning can be done by homeowners, extensive mold growth typically requires professional remediation.

For light surface mold on accessible coils, start by turning off power to the unit at both the thermostat and electrical panel. Remove the access panel to expose the evaporator coil (usually above your furnace). Use a soft brush to gently remove loose debris, then spray the coils with a no-rinse foaming coil cleaner specifically designed for HVAC systems. These cleaners are available at HVAC supply stores and are formulated to kill mold while being safe for the coil materials.

Never use bleach or harsh chemicals on AC coils, as these can corrode the aluminum fins and copper tubing, leading to expensive repairs. The coil cleaner should foam up and drip into the drain pan below - this is normal. After cleaning, replace your air filter with a high-quality MERV 8-11 filter to prevent future mold growth.

In Ottawa's humid climate, mold growth on AC coils is common, especially in basements or poorly ventilated areas. However, extensive mold growth, black mold, or mold that returns quickly after cleaning indicates a deeper problem with humidity control or drainage that requires professional attention. Professional duct cleaning services can also sanitize the entire system and identify the root cause of moisture problems.

Safety is paramount when dealing with mold - wear protective equipment including N95 mask, gloves, and eye protection. If you have respiratory issues or the mold covers a large area, contact a professional HVAC technician who has proper equipment and training for mold remediation.

For comprehensive mold remediation and system sanitization, Ottawa HVAC Pro offers professional duct cleaning services that include coil cleaning and antimicrobial treatment to prevent future mold growth.