If running your HVAC means your allergies worsen and you sneeze more, you should be concerned. Your air quality should not worsen while your HVAC system is running, as the system should ideally be helping to circulate and filter the air.
If the air quality is noticeably poor (e.g., strong odors, visible dust, respiratory irritation), turning off the system will stop it from circulating the contaminated air further.
Open windows and doors (if outdoor air quality permits) to introduce fresh air and help dissipate the poor indoor air. Use fans to help circulate the fresh air.
This is the first and easiest thing to inspect. A dirty or clogged air filter is a very common reason for poor air quality when the HVAC is running. Look at it – is it visibly dirty, dusty, or blocked? When was it last changed? Most standard 1-inch filters need to be changed every 1-3 months, more frequently if you have pets, allergies, or dusty conditions. Then, replace it immediately. If the filter is dirty, replace it with a clean filter of the correct type and size for your system.
Dust and debris accumulates on these components and become circulated into your home’s air.
Mold, mildew, and dust grow on these coils, especially if there’s excessive humidity. When the system runs, it can blow these contaminants into your home.
Dust, allergens, mold spores, and other debris can accumulate inside your ductwork over time. The HVAC system then distributes these contaminants throughout your house.
Poor drainage from the HVAC system leads to condensation buildup, creating a breeding ground for mold and mildew in the unit or ductwork.
Mold grows in other humid areas of your home (bathrooms, basements) and is circulated by the HVAC system.
While less common, refrigerant leaks can sometimes have a noticeable odor (though not always). This requires professional attention immediately.
If the condensate drain pan is full or the drain line is blocked, it can lead to water buildup and potential mold growth.
These can off-gas volatile organic compounds (VOCs) that affects air quality, especially when the HVAC system circulates the air.
Improper use or storage of strong cleaning products or chemicals can release fumes that are circulated by the HVAC.
Dust and debris from recent renovations are trapped in the HVAC system and distributed.
Rodent or insect infestations in ductwork can introduce allergens and contaminants.
If there are no obvious causes, and the simple remediations have no effect, then you’re at a point to schedule professional HVAC maintenance with Fast Heating and Air. If a new air filter doesn’t resolve the issue, it’s crucial to have a qualified HVAC technician inspect and clean your system. We will: Thoroughly clean the blower motor, fan, and coils; Check for mold and mildew growth; Inspect the ductwork for cleanliness and leaks; Ensure proper drainage of the condensate pan; Check for refrigerant leaks.
Likewise, consider professional duct cleaning. If you suspect significant buildup in your ductwork, consider having it professionally cleaned.
After you’ve engaged the fixes, there’s steps you can take to lessen the chances of a repeat problem:
Even with a good HVAC system clean, ensure adequate ventilation by opening windows periodically (when outdoor air quality is good) or using exhaust fans in kitchens and bathrooms.
High humidity contributes to mold growth. Use dehumidifiers in damp areas and ensure proper ventilation in bathrooms and kitchens. Aim for a relative humidity between 30% and 50%. If not controlling the humidity, consider a whole-house dehumidifier.
Address Potential Sources of Contamination: Identify and eliminate any obvious sources of indoor air pollution, such as chemical fumes or mold growth outside of the HVAC system.
Standalone air purifiers with HEPA filters and activated carbon filters can remove small particulate matter, allergens, and some odors from the air. If smaller room-size purifiers do not improve air quality, then consider upgrading to whole-house air purifiers.
Schedule regular professional maintenance with Fast Heating and Air for your HVAC system (at least annually) to ensure it's clean, functioning efficiently, and contributing to good indoor air quality.
Depending on your system and needs, you might consider using a higher-MERV rated air filter, but always check your HVAC system's specifications to ensure it can handle the increased airflow resistance.
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Fast Heating and Air Poor indoor air quality when your HVAC system is running often indicates a problem within the system itself or something the system is circulating. Start with the simple step of changing your air filter. If the issue persists, it’s essential to have a Fast Heating and Air professionally inspected and cleaned to identify and address the underlying cause.
Poor air quality is often caused by a dirty HVAC filter, mold in the system, blocked ducts, high humidity, or even fumes from cleaning products and new furniture. These contaminants circulate through your HVAC system, worsening indoor air.
Common signs you need an air filter replacement include increased dust, worsened allergies, reduced airflow, or strange odors when your HVAC runs. Most filters should be replaced every 1–3 months.
Symptoms of a dirty HVAC filter include musty smells, reduced airflow, increased sneezing or allergy flare-ups, and unusual dust buildup in your home.
Yes. Poor indoor air quality can cause or worsen headaches, especially if the air contains mold spores, VOCs, dust, or other irritants. A properly maintained HVAC system can help reduce these risks.
If you notice visible dust from vents, musty smells, or allergy symptoms when the HVAC runs, duct cleaning services may be necessary to remove built-up contaminants from your ductwork.
Call for emergency HVAC service if you notice strong odors, visible mold, refrigerant leaks, or if the system stops working while circulating poor-quality air. These can pose health risks and require immediate attention.
Yes. Whole-home air purifiers work with your HVAC system to remove allergens, dust, and odors throughout the house—offering a more comprehensive solution than standalone units.
For serious air quality issues, a whole-home air purifier with a HEPA filter and activated carbon layer is recommended. It traps small particles, allergens, and VOCs better than standard filters.
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