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How Your Furnace Affects Indoor Air Quality

how your furnace affects indoor air quality

As winter settles in and temperatures drop, the furnace becomes a vital part of maintaining comfort in our homes. While it's easy to focus on how well the furnace is heating the home, many homeowners overlook an equally important aspect: how their furnace impacts indoor air quality (IAQ). Indoor air quality is a significant factor in our overall health and well-being, yet it's something that is often taken for granted. In this blog, we’ll explore how your furnace can influence the air you breathe and what steps you can take to ensure that your home remains both warm and healthy throughout the colder months.

Understanding Indoor Air Quality

Before diving into how a furnace affects IAQ, it's essential to understand what indoor air quality entails. IAQ refers to the quality of the air inside a building or home, particularly with regard to the health and comfort of its occupants. Factors such as humidity, temperature, air pollutants, and ventilation all play a significant role in determining IAQ.

Poor indoor air quality can lead to a variety of health issues, from minor irritations like dry skin, itchy eyes, and a sore throat to more severe respiratory problems, especially for individuals with asthma, allergies, or other pre-existing conditions. These concerns make it all the more important to monitor and maintain good IAQ in your home.

How Your Furnace Impacts Indoor Air Quality

Your furnace plays a significant role in shaping the air quality inside your home. It heats the air, circulates it throughout the house, and can either help or hinder air quality depending on its age, condition, and how well it is maintained.

1. Dirty Furnace Filters

One of the most common culprits of poor indoor air quality is a dirty furnace filter. Over time, filters can accumulate dust, pet dander, pollen, and other airborne particles, which reduces their ability to trap contaminants. When the filter is clogged, it allows these pollutants to circulate throughout your home, affecting the air you breathe. This can be especially problematic for individuals with allergies, asthma, or other respiratory conditions, as the airborne allergens can exacerbate symptoms. Regularly changing or cleaning your furnace filter is one of the easiest and most effective ways to improve air quality and ensure your furnace is running efficiently.

2. Air Circulation and Distribution

One of the primary functions of your furnace is to distribute warm air throughout your home. As the furnace blows heated air through the ducts, it pushes air into different rooms. If your ducts are dirty or clogged with dust and debris, they can introduce these particles back into the air you breathe. Over time, this can lead to an accumulation of pollutants, which is particularly concerning for individuals with respiratory conditions or allergies.

Additionally, many homes today are sealed tightly to increase energy efficiency, which means that air circulation can become stagnant if there isn't proper ventilation. Without a proper exchange of fresh outdoor air, pollutants generated inside the home—whether from cooking, cleaning, or even just breathing—can accumulate and cause health problems.

3. Dust and Allergens

Dust is one of the most common pollutants in indoor air, and it is often stirred up and circulated by the furnace. If your furnace is not regularly maintained, dust, pet dander, and other allergens can build up inside the system. When the furnace is turned on, these particles are blown into the air, exacerbating allergies and asthma symptoms.

Dust buildup in the furnace’s filter is a significant contributor to poor IAQ. The filter in your furnace is designed to trap dust and other particles before they are circulated into the home. However, over time, filters become clogged, reducing their efficiency. A clogged filter can allow dust, pet hair, and other allergens to pass through and spread throughout your living spaces.

4. Dry Air and Humidity Issues

Furnaces, especially older models, can dry out the air in your home. As the furnace heats the air, it reduces the humidity levels inside your house. While this is usually not a problem during the warmer months, the lack of humidity in winter can cause discomfort and exacerbate health issues.

Dry air can cause your skin to feel dry, your throat to become scratchy, and even trigger sinus and respiratory problems. For those with asthma, eczema, or other chronic conditions, dry air can worsen symptoms and make it harder to breathe.

5. Carbon Monoxide Risks

A furnace that is not properly maintained or is malfunctioning can be a potential source of dangerous carbon monoxide (CO). CO is a colorless, odorless gas that can be deadly in high concentrations. While most modern furnaces are designed with safety features to prevent CO buildup, older models or those with issues like cracked heat exchangers can leak CO into your home.

To mitigate this risk, it’s essential to have your furnace inspected and serviced regularly by a professional. Additionally, installing a carbon monoxide detector near your furnace and throughout your home can help alert you to potential issues before they become dangerous.

6. Mold and Mildew Growth

Furnaces can also contribute to indoor air pollution by encouraging the growth of mold and mildew. If your furnace is located in a damp area such as a basement or crawl space, it can create the perfect environment for mold to thrive. When mold spores are circulated through the air, they can contribute to respiratory issues, allergies, and other health problems.

In homes with high humidity levels, poor furnace maintenance or inadequate ventilation can exacerbate mold growth. Keeping humidity levels in check and ensuring proper airflow can help reduce the risk of mold and mildew development.

Tips for Improving Indoor Air Quality with Your Furnace

Now that you understand how your furnace can affect IAQ, here are several steps you can take to improve the air quality in your home:

1. Regularly Change or Clean Your Furnace Filters

One of the simplest and most effective ways to improve IAQ is by ensuring that your furnace filter is clean. Most filters should be replaced every 1–3 months, depending on the type and manufacturer recommendations. If you have pets or live in a dusty area, you may need to change it more frequently. A clean filter helps trap dust, pet dander, and other allergens, preventing them from circulating through your home.

2. Schedule Annual Furnace Maintenance

To ensure that your furnace is operating efficiently and safely, it’s essential to have it inspected and maintained annually. A licensed HVAC professional can check for potential issues, clean the furnace, and ensure that everything is functioning correctly. Regular maintenance helps prevent dangerous situations, such as carbon monoxide leaks, and ensures that your furnace doesn’t contribute to poor IAQ.

3. Invest in an Air Purifier

Air purifiers can be a great addition to your home, especially if you are concerned about allergens, dust, or other pollutants. Many modern air purifiers are designed to work with your HVAC system, filtering the air as it is circulated through the ducts. Alternatively, standalone units can be placed in rooms where air quality is a concern, such as the bedroom or living room.

4. Control Humidity Levels

To prevent dry air, consider using a humidifier in your home, particularly in areas where the air tends to be the driest. Maintaining optimal humidity levels (30-50%) can help reduce dryness, prevent the spread of viruses, and improve comfort. You can also invest in a whole-house humidifier that connects directly to your HVAC system.

5. Ensure Proper Ventilation

Make sure your home is properly ventilated to allow fresh air to circulate and reduce the buildup of indoor pollutants. This is especially important if your home is tightly sealed for energy efficiency. You can increase ventilation by opening windows when weather permits, using exhaust fans in the kitchen and bathroom, or installing a heat recovery ventilator (HRV) or energy recovery ventilator (ERV).

Contact LA Construction, Heating and Air

Your furnace plays an important role in maintaining both the temperature and air quality inside your home. From circulating dust and allergens to introducing risks like carbon monoxide, it’s important to be aware of how your furnace affects indoor air quality. By following basic maintenance steps, such as changing filters, controlling humidity, and scheduling annual inspections, you can improve the air quality in your home and ensure that it remains a safe, healthy environment for you and your family. Contact LA Construction, Heating and Air to schedule your annual furnace maintenance today! 

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Whether you're at home or at work, your health and comfort can be affected by poor air quality. And, the air quality is affected by the air temperature, the humidity, the quality of ventilation and any contaminants or irritants like indoor pets, pollen, dust mites, cleaning products, lead, Formaldehyde and Asbestos, Poor Air Flow, mildew and mold. Poor air quality can cause more than slight discomfort - much more!

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