Why Your AC Struggles During Extreme Heat

When It’s Over 95°F in Chicago: Why Your AC Can’t Keep Up and How Proper Sizing Makes All the Difference

If you live in the Chicago suburbs, you’re no stranger to those scorching summer days when temperatures soar above 95°F. It’s frustrating—you crank the air conditioning, but your home still feels warm and sticky. Your cooling system seems to run constantly, yet comfort remains elusive. If this scenario sounds familiar, you're not alone. Even the best HVAC systems struggle in extreme heat conditions. The culprit? Often, it's related to the sizing—or tonnage—of your AC system.

Why Your AC Struggles During Extreme Heat

Central air conditioners are designed to handle typical summer conditions, usually temperatures ranging between 80°F and 90°F. But when temperatures spike over 95°F, these units have to work overtime, and often, their capacity simply can't keep up.

Imagine trying to cool down your overheated car with a small desk fan—it's insufficient and ineffective. Similarly, when the outdoor temperatures push beyond your system’s design limits, your AC struggles to maintain indoor comfort. Heatwaves not only challenge the cooling capacity of your system but also significantly impact your indoor air quality, as warm air and humidity make your home uncomfortable.

The Importance of Proper AC Sizing

Proper AC sizing—often referred to as "tonnage"—is critical to maintaining comfort, especially during the cooling season. Air conditioning units are measured in tons, with one ton equal to 12,000 BTUs (British Thermal Units) of cooling power per hour. The right-sized AC ensures balanced cooling, humidity control, and energy saving, optimizing both comfort and utility bills.

Issues with Undersized AC Units

An undersized air conditioner can’t adequately cool your home during extreme temperatures. It runs continuously, driving up energy bills without ever achieving the desired indoor temperature. This relentless operation also shortens the lifespan of your system and can lead to increased repair needs.

Common signs of an undersized AC include:

• Continuous operation without reaching set temperature
• Uneven cooling with noticeable hot spots
• Higher energy costs
• Increased humidity, reducing indoor air quality

Problems with Oversized AC Units

Bigger isn't always better when it comes to air conditioning. Oversized units quickly cool the air but shut off prematurely. This rapid cycling fails to adequately remove humidity, leaving your indoor air quality feeling clammy and uncomfortable.

Symptoms of an oversized AC include:

• Frequent short cycling
• High indoor humidity
• Increased energy consumption
• Reduced system lifespan due to excessive wear and tear

Practical Tips to Stay Comfortable During Extreme Heat

Here are some cost-effective steps you can take to help your AC system and keep your home comfortable during those extreme Chicago summers:

• Use Ceiling Fans: Fans circulate cool air, allowing you to set your thermostat a few degrees higher without sacrificing comfort.
• Close Blinds and Curtains: Keeping blinds and curtains closed, especially on sunny sides of the home, significantly reduces heat gain.
• Regular AC Maintenance: Schedule regular HVAC maintenance to ensure your system is clean and running efficiently. A well-maintained AC can handle heat better and save energy.
• Smart Thermostats: Installing smart thermostats helps regulate indoor temperatures more efficiently, ultimately helping you save money on energy bills.
• Seal and Insulate Your Home: Proper insulation and sealing gaps can prevent warm air from entering your home, further reducing energy costs.

Choosing the Right AC Size for Your Home

Properly sizing your air conditioning system involves a professional calculation called a Manual J Load Calculation. This process considers numerous factors, including:

• Home size and layout (square feet)
• Insulation quality
• Number and placement of windows
• Orientation of the home to the sun
• Number of occupants and heat-generating appliances
• Whether you have an outdoor unit, indoor unit, or window air conditioner
• The potential use of a heat pump as an alternative or complement to traditional central air conditioners

Professional load calculations ensure you select an AC unit that matches your home’s specific cooling and humidity-control needs. This not only provides optimal comfort but also helps keep your energy costs manageable by reducing unnecessary energy usage.

How the Right AC Sizing Can Save You Money

Choosing the right-sized cooling system is not only beneficial for comfort but also cost-effective. Properly sized AC units run efficiently, reducing wear and tear on both the indoor and outdoor units. This efficiency translates directly to lower energy bills and reduced energy costs throughout the cooling season. Over time, these savings can significantly offset the initial cost of professional AC sizing and installation.

FAQs about AC Performance, Sizing, and Humidity

Q1: My AC runs constantly during heatwaves. Is something wrong?

A: Not necessarily. During extreme heat, even well-sized units run longer. However, if your home never reaches the set temperature, your unit might be undersized or need servicing.

Q2: Does higher tonnage always mean better cooling?

A: No. Oversized units can cause rapid cycling and humidity issues, leading to discomfort and inefficiency.

Q3: How often should I schedule AC maintenance?

A: At least once annually. Regular maintenance keeps your system efficient and identifies potential issues before they become costly problems.

Q4: Can humidity affect my AC’s performance?

A: Absolutely. High humidity levels make your home feel warmer and force your AC to work harder, impacting efficiency and comfort.

Q5: Can ceiling fans help my AC cool the house better?

A: Yes. Fans circulate air, allowing for better cooling efficiency and comfort without lowering the thermostat excessively.

Need Help Keeping Cool in Chicago’s Heatwaves?

At Always Ready Repair, we understand how crucial comfort is, especially during sweltering Chicago summers. If you suspect your AC might not be sized correctly, or if you're experiencing persistent issues with cooling and humidity, we're here to help.

Contact us today for professional AC sizing consultations, maintenance, or HVAC system upgrades. Stay cool, comfortable, and efficient—even during the hottest days in the Chicago suburbs!

Additional Resources:

• Energy Star Guide to Sizing Your Air Conditioner
• U.S. Department of Energy: Air Conditioning Tips
• ASHRAE Manual J Load Calculation Information

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