What is that Smell? Should I be Worried?

Identifying HVAC Odors in Your Home—and When to Take Action

Unusual smells in your home can be alarming—especially when they come from your heating and cooling system. Some odors are harmless, but others can signal serious issues. At Arco Heating & Cooling, we help homeowners identify HVAC-related smells and determine when it's time to worry—and take action.

Common HVAC Smells and What They Mean

1. Burning Dust

Smells like: Burning or dusty odor When it happens: Usually when turning on your heat for the first time in the season Should you worry? Not usually. It’s common and usually goes away quickly as dust burns off your heating elements.

2. Electrical or Burning Plastic Smell

Smells like: Hot wires, melting plastic When it happens: While the system is running Should you worry? Yes. This may signal overheating parts, frayed wires, or a serious electrical issue. Turn off the system and call a professional immediately.

3. Rotten Egg or Sulfur Smell

Smells like: Sulfur, rotten eggs When it happens: At any time Should you worry? Absolutely. This could indicate a natural gas leak. Leave your home immediately and contact your gas provider and HVAC technician.

4. Musty or Moldy Smell

Smells like: Damp basement, mildew When it happens: Often when the AC runs Should you worry? Yes. This could be a sign of mold or mildew in your ducts or system. Not only can this affect indoor air quality, but it can also impact your family’s health.

5. Sewage or Dead Animal Smell

Smells like: Foul, decaying odor When it happens: Sporadically or continuously Should you worry? Yes. You might have a pest problem or a sewage backup near your HVAC system. Call a professional to inspect it.

What To Do If You Notice a Strange Smell

Don’t ignore it. Even if the smell seems minor, it could be a warning sign.
Turn off your system if the smell is electrical, smoky, or foul.
Call a licensed HVAC professional like Arco Heating & Cooling to diagnose the issue safely and quickly.

Trust Arco Heating & Cooling to Sniff Out the Problem

Our team has the tools and experience to diagnose strange odors and fix HVAC issues fast. Whether it’s a routine cleaning, an electrical fix, or system replacement, we’re here to help keep your home safe and comfortable. As a trusted heating and cooling contractor based in St. Charles, MO, we proudly serve the entire St. Louis metropolitan area, including both Missouri and Illinois.

Call ARCO Heating & Cooling today at (636) 389-6471 to schedule your inspection and get peace of mind!

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The Importance of Indoor Air Quality in Transitional Seasons

By ARCO HEATING AND COOLING • April 25, 2025

How Seasonal Shifts Impact the Air You Breathe When spring turns into summer or fall shifts into winter, your home’s indoor air quality (IAQ) can change dramatically. These transitional seasons bring fluctuating temperatures, increased allergens, and different HVAC usage patterns—all of which can affect the health and comfort of your indoor environment. At Arco Heating & Cooling , we’re here to help you understand these shifts and keep your home’s air clean and comfortable year-round. What Happens to Indoor Air Quality in Transitional Seasons? More Time Indoors, More Exposure As temperatures become unpredictable, people tend to spend more time inside. While this keeps you comfortable, it also means you’re breathing indoor air more frequently—and if that air is filled with dust, pollen, or other irritants, it can take a toll on your health. Allergens Are on the Move Spring and fall are peak seasons for pollen, mold spores, and other allergens. Without proper filtration and ventilation, these particles can easily find their way indoors and linger in your HVAC system. HVAC Systems Kick Into Gear Transitional seasons often involve switching between heating and cooling. This inconsistent use of your HVAC system can lead to dust buildup in filters and ducts, impacting air quality and system efficiency. Signs of Poor Indoor Air Quality Persistent allergy symptoms Dust buildup near vents Musty or stale indoor smells Dry skin or throat irritation Excess humidity or dryness If you're experiencing any of these, it may be time to improve your indoor air quality. Arco Heating & Cooling’s Indoor Air Quality Solutions Tailored to Missouri and Illinois Homes We offer a range of products and services designed to enhance IAQ throughout transitional seasons: Air purifiers : Capture and remove airborne particles including pollen, dust, and bacteria. Humidifiers and dehumidifiers : Balance humidity levels to prevent mold growth and dry air discomfort. HEPA filters : High-efficiency filters for cleaner, healthier air. Duct cleaning services : Eliminate built-up dust, mold, and debris in your ductwork. Smart HVAC controls : Automate air quality monitoring and adjustments for convenience and efficiency. Our expert team will assess your needs and recommend the right solution to improve your indoor air all year long. Breathe Better This Season—and Every Season Your home should be a safe, comfortable place, no matter the weather outside. By investing in indoor air quality solutions, you protect your health, enhance comfort, and improve HVAC efficiency. Let Arco Heating & Cooling help you transition smoothly into every new season. As a trusted heating and cooling contractor based in St. Charles, MO , we proudly serve the entire St. Louis metropolitan area, including both Missouri and Illinois. Call ARCO Heating & Cooling today at (636) 389-6471 to schedule your indoor air quality consultation. Breathe easier with expert solutions tailored to your home.

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How to Choose the Right HVAC System for Your Home Size

By ARCO HEATING AND COOLING • April 25, 2025

Find the Perfect HVAC Fit for Your Home's Comfort and Efficiency Selecting the right HVAC system isn’t just about brand or features—it’s about choosing a unit that fits your home’s size and layout. An improperly sized system can lead to high energy bills, uneven temperatures, and unnecessary wear and tear. At Arco Heating & Cooling , we help you choose the perfect system for optimal performance and year-round comfort. Why HVAC System Size Matters An HVAC system that’s too large or too small can cause a variety of issues: Oversized systems short-cycle, leading to inefficient operation and uneven temperature control. Undersized systems run constantly, struggle to maintain comfort, and lead to higher energy usage and faster wear. Correct sizing ensures maximum efficiency, lower utility bills, and a longer-lasting system. Key Factors in HVAC Sizing 1. Square Footage of Your Home The size of your home is the most critical factor. HVAC systems are rated in BTUs (British Thermal Units), and each square foot of living space typically requires a certain number of BTUs. 2. Climate Zone Homes in colder or hotter climates require more powerful systems to maintain comfort. Missouri’s four-season weather means your HVAC system needs to handle both heating and cooling efficiently. 3. Home Layout and Insulation High ceilings, window placement, and insulation quality can impact your home’s heating and cooling needs. A well-insulated home may require a smaller unit than a drafty one. 4. Number of Occupants and Appliances More people and heat-generating appliances (like ovens) can affect your home's internal temperature and should be factored into system sizing. Let Arco Heating & Cooling Help Choosing the right HVAC system doesn't have to be a guessing game. Arco Heating & Cooling offers expert consultation services to: Evaluate your home’s size, layout, and needs. Recommend HVAC systems based on BTU requirements and efficiency ratings. Provide professional installation and ongoing maintenance for peak performance. Get the Right System, the First Time Don’t risk investing in the wrong HVAC setup. Let the experts at Arco Heating & Cooling guide you toward a system that fits your home, budget, and comfort goals perfectly. As a trusted heating and cooling contractor based in St. Charles, MO , we proudly serve the entire St. Louis metropolitan area , including both Missouri and Illinois. Call ARCO Heating & Cooling today at (636) 389-6471 to schedule your HVAC consultation and make the smart choice for your home!