Common mistakes to avoid when installing a central AC system

Installing a central AC system in your home can seem like a daunting task, but with the right knowledge and tools, it’s definitely doable for the DIYer. Getting it right can save you money, improve your home’s comfort, and extend the life of your new system. However, avoiding common mistakes during installation is key to ensuring your system works efficiently and reliably. We’ll walk you through some of the most common pitfalls to avoid when installing your central AC system and how you can prevent them from happening. 

The information in this article might not match up exactly with your specific appliance model. We do our best to provide helpful tips for all kinds of DIY repairs, but different models and setups can mean different troubleshooting steps, error codes, parts, etc. For the best details, we highly recommend checking out the manufacturer’s docs for your exact model or contact us if you have any questions.

Mistake 1: Choosing the wrong size system

One of the biggest mistakes you can make when installing a central AC system is choosing the wrong size. The size of your system affects its ability to cool your home effectively, and using one that’s too small or too large can lead to problems.

• A unit that’s too small won’t cool your home properly, causing it to run constantly and driving up energy costs.
• A unit that’s too large will cool the space too quickly, leading to inefficient operation and short cycling.
• To determine the right size, consider factors like your home’s square footage, the amount of insulation, and the climate you live in. A good rule of thumb is to use 20 BTUs per square foot.
• Also, take into account the number of rooms and the layout of your space. Larger homes may need more than one unit or additional zoning.

Mistake 2: Incorrect installation of the ductwork

Properly installed ductwork is crucial for the efficiency of your central AC system. If the ducts are improperly sized, poorly sealed, or obstructed, your system will struggle to cool your home and may cause unnecessary wear and tear.

• Ensure your ductwork is the right size for your system. Undersized ducts can restrict airflow, leading to uneven cooling, while oversized ducts can make the system inefficient.
• Check for leaks in your ductwork. Even small holes can reduce the system’s efficiency by allowing cooled air to escape.
• Properly insulate ducts, especially those in attics or unconditioned spaces. This helps prevent energy loss and ensures that cooled air reaches the desired rooms.
• Avoid placing ducts where they could be obstructed by furniture or other items. This will allow air to flow freely and maximize the system’s efficiency.

Mistake 3: Choosing the wrong location for the outdoor unit

Where you place the outdoor unit of your central AC system plays a huge role in how efficiently it operates. An improper location can lead to poor performance, higher energy costs, and potential damage to the unit.

• Make sure the unit is placed in an open, well-ventilated area. Avoid placing it near walls, shrubs, or any objects that could block the airflow and restrict the condenser’s function.
• Ensure the unit is positioned on a stable, level surface. An unstable foundation can cause vibrations, resulting in wear and tear over time.
• Place the outdoor unit in a shaded area if possible to prevent it from overheating in direct sunlight, which can strain the system and reduce efficiency.
• Avoid placing the unit too close to windows, doors, or vents to prevent the hot air from being recirculated back into the system.

Mistake 4: Forgetting to set the thermostat correctly

One of the simplest but most overlooked mistakes when installing a central AC system is failing to set the thermostat correctly. Proper thermostat settings are crucial for ensuring your system runs efficiently and doesn’t waste energy cooling your home unnecessarily.

• Avoid setting the thermostat too low. If it’s too cold, your system will run longer than needed, wasting energy. Aim for a comfortable temperature between 72°F and 75°F for maximum efficiency.
• Many modern thermostats allow you to set different temperatures for different times of day. For instance, you can set the temperature higher when you’re not home and lower it when you return, saving energy.
• If your system allows, zone control can help you cool different areas of your home to different temperatures, improving efficiency.

Mistake 5: Forgetting to install a proper drainage system

Your AC unit removes moisture from the air as it cools, and this moisture needs to be properly drained away to avoid water damage, mold growth, and system malfunctions.

• Without proper drainage, excess water can accumulate in the system, potentially causing leaks or even water damage to your home.
• A clogged or improperly installed drain line can cause water to back up into the system, damaging the compressor or other parts.
• Ensure the drain line is properly positioned, sloped, and clear of debris to allow water to flow freely. Regular maintenance of the drainage system is necessary to prevent clogs.

More help

Need parts, detailed repair guidance, or have questions about specific models? Don’t forget to check out how to find your appliance’s model number. Stay in the loop with us on Facebook and Twitter for more tips and updates. Don’t hesitate to reach out if you need a hand or want to share your DIY wins, our repair help can guide you step by step. Thanks for being part of the AppliancePartsPros.com community!

If you need extra support, give us a call or use the contact form on our website. Together, we’ll make sure you get a well-installed, long-lasting central AC system that keeps your home cool just the way you like it.

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