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Clearing the Air: Investigating Chemical Smells and Mold in Your Furnace or Air Handler

Chemical Smells Around Your Furnace or Air HandlerHave you ever walked by your furnace or air handler and noticed a strong chemical smell? If so, it’s important to investigate the cause and address it promptly.

In this article, we will explore two main topics related to chemical smells near your furnace or air handler. Firstly, we’ll discuss the various chemicals that could be causing the smell, and how to identify them.

Secondly, we’ll delve into refrigerant leaks, another common cause of chemical odors, and the steps you should take to address them. By the end of this article, you’ll have a better understanding of these issues and how to handle them.

Chemicals Near the Furnace or Air Handler

Identifying chemicals near the furnace or air handler

– Chemical smell: If you’re perceiving a strong chemical odor near your furnace or air handler, it’s crucial to identify the source to ensure your safety. – Flooring: New carpet or flooring can release volatile organic compounds (VOCs) that produce a chemical smell.

Consider low-VOC flooring options if you’re sensitive to odors. – Paint cans and solvents: Leftover paint cans or solvents stored near the furnace or air handler can emit strong chemical odors.

Ensure proper storage to prevent fumes from spreading. – Cleaning supplies: Certain cleaning supplies contain strong chemicals that can produce odors.

Store them in a well-ventilated area away from the furnace or air handler. – Fertilizer and lawn chemicals: If you store lawn chemicals near your furnace or air handler, their odors can permeate the area.

Relocate them to an appropriate storage location. – Sealer and other products: Any recent application of products such as sealers can release strong chemical smells.

Consider proper ventilation during and after application. – Odor test: To pinpoint the source of the smell, you can perform an odor test by moving carefully around the furnace or air handler, noting any specific areas where the smell is stronger.

Resolving the issue of chemical smell

– Store the product: If the smell is identified as coming from a specific product, move it to another area away from the furnace or air handler. – Contact the seller or installer: If you’ve recently had flooring or other products installed, contact the seller or installer to discuss the odor issue and potential solutions.

– Low-VOC flooring: When choosing new flooring, opt for low-VOC options to minimize chemical odors. – Professional odor test: If you’re unable to locate the source of the smell, consider hiring a professional to perform an odor test that can pinpoint the problem area.

– Proper ventilation: Ensure adequate ventilation around the furnace or air handler to prevent any trapped odors from lingering. – Seek professional assistance: If the smell persists or becomes overwhelming, contact a professional HVAC technician who can inspect the system and provide guidance on resolution.

Refrigerant Leak

Identifying a refrigerant leak

– Chemical smell: A refrigerant leak can produce a distinct chemical smell that resembles sweet aromas or a pungent odor. – Fluid leak: If you notice any fluid pooling near your air handler, it could be a sign of a refrigerant leak.

– Coil and refrigerant line inspection: Examine the coil and refrigerant lines for any signs of visible leaks, such as stains or corrosion. – Corroded connections: Check for corroded connections in the refrigerant lines as they can cause leaks and contribute to the chemical smell.

Addressing a refrigerant leak

– Investigate the leak: If you suspect a refrigerant leak, it’s crucial to investigate further. Turn off the system and contact a professional HVAC company for assistance.

– Call a professional service: It’s advisable to call a professional HVAC technician who is certified in handling refrigerants to inspect and repair any leaks. – Refrigerant certification: Ensure that the HVAC technician has the necessary certifications to handle and work with refrigerants safely and legally.

– Replace line or coil: Depending on the extent of the leak, the HVAC technician may recommend replacing the damaged line or coil to prevent future leaks. – Charge refrigerant: After repairing the leak, the HVAC technician will recharge the system with the appropriate refrigerant (e.g., R22 or R410A) to ensure optimal performance.

– Replacement cost: In some cases, if the damage is severe, it may be more cost-effective to replace the entire system. Consult with the HVAC technician to determine the best course of action.


Understanding the sources and implications of chemical smells near your furnace or air handler is essential for maintaining a safe and comfortable home. By identifying the chemicals causing the odor and promptly addressing any issues, you can breathe easy knowing that you’ve taken the necessary steps to keep your indoor air quality at its best.

Don’t hesitate to contact a professional HVAC technician if you suspect a refrigerant leak or if the chemical smell persists. They have the expertise to diagnose the problem and provide the appropriate solutions.

Stay vigilant about potential chemical smells, and enjoy a healthier and more pleasant living environment.

Mold on the AC Coil or Drip Pan

Identifying mold growth

If you notice a persistent musty smell or detect an acidic odor resembling ammonia near your air conditioning unit, there is a possibility that mold is present on the AC coil or drip pan. Identifying mold growth is crucial as it can negatively impact indoor air quality and potentially trigger respiratory issues.

Here are some steps to help you determine if mold is the culprit:

– Chemical odor: Mold often emits a distinct musty smell. If you encounter a persistent odor near your air conditioning unit that resembles a damp basement or old socks, it could indicate the presence of mold.

– Visual examination: While mold may not always be visible due to its location within the AC system, conducting a visual inspection can be helpful. Use a flashlight and handheld mirror to examine the coil and drip pan for any signs of mold growth.

Look for discolored patches, fuzzy or slimy textures, or dark spots. – AC system performance: Mold growth can affect the performance of your air conditioning system.

If there is a noticeable decrease in cooling efficiency or an increase in energy consumption, it might be an indication of mold on the coil or pan. – Health symptoms: Pay attention to any health symptoms that arise when the air conditioning system is running.

If you experience respiratory issues such as coughing, sneezing, or difficulty breathing, it could be a sign of mold contamination in the indoor air.

Treating mold growth

Once you have confirmed mold growth on your AC coil or drip pan, it’s essential to take prompt action to clean and treat the affected areas. While some homeowners may choose to tackle the task themselves, it is strongly recommended to call a professional air conditioning company due to the potential risks involved.

Here are some options for treating mold growth:

– Call an air conditioning company: Contacting a professional air conditioning company is the safest and most efficient way to address mold growth on your AC coil or drip pan. These professionals have the expertise, equipment, and necessary safety measures to effectively remove the mold and ensure a thorough cleaning.

– DIY cleaning: If you prefer to handle the cleaning yourself, exercise caution and follow these steps:

1. Turn off the air conditioning system and ensure it is completely powered down.

2. Put on protective gear such as gloves, goggles, and a mask to prevent exposure to mold spores.

3. Apply a specialized coil cleaner or a solution of equal parts water and white vinegar to the affected areas.

Use a soft brush or cloth to scrub gently and remove the mold. 4.

Rinse the coil and pan thoroughly with clean water to remove any residue or cleaning solution. 5.

Allow the coil and pan to dry completely before turning the system back on. – Bleach solution: As an alternative to white vinegar, a diluted bleach solution can be used to remove mold.

Mix one part bleach with four parts water and apply it to the affected areas. Remember to wear protective gear and rinse the coil and pan thoroughly after cleaning.

– Pan tablets: If you frequently encounter mold growth in the drip pan, consider using pan tablets. These tablets are specifically designed to prevent and control mold and algae growth in the pan.

Follow the manufacturer’s instructions for proper usage. – Cost of cleaning: The cost of professional mold removal from the AC coil or drip pan will vary depending on factors such as the severity of the mold growth, accessibility, and the company you hire.

It is recommended to obtain multiple quotes from reputable air conditioning companies to get an accurate estimate for the cleaning service. – AC tune-up: While addressing mold growth, consider scheduling a professional AC tune-up as well.

Regular maintenance can help prevent mold growth by ensuring proper airflow, checking refrigerant levels, and cleaning or replacing air filters. This will not only improve indoor air quality but also enhance the overall efficiency and lifespan of your air conditioning system.


Identifying and treating mold growth on your AC coil or drip pan is vital for maintaining a healthy and comfortable indoor environment. If you detect a musty or acidic odor near your air conditioning unit or notice any visual signs of mold, it’s important to take immediate action.

Contacting a professional air conditioning company is the best approach to effectively remove the mold and prevent further contamination. However, if you choose to tackle the cleaning yourself, remember to take appropriate safety precautions and follow the recommended methods using specialized coil cleaners, white vinegar, or a diluted bleach solution.

Additionally, consider using pan tablets to prevent future mold growth and schedule regular AC tune-ups to maintain optimal system performance. By addressing mold growth promptly and thoroughly, you can ensure clean and fresh indoor air quality throughout your home.

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