AC Taking Long to Cool House

As summer temperatures rise, you may find your AC taking long to cool house, leaving you in discomfort during the hottest parts of the day. This common issue can be due to a variety of factors, from simple problems like incorrect thermostat settings to more serious issues like an old or undersized AC unit.

In this comprehensive guide, we will explore all these potential problems, providing you with step-by-step instructions to diagnose and resolve each one. Whether your AC taking long to cool house due to a dirty air filter, or you’re considering an AC upgrade, we’ve got you covered. Stay tuned to learn how to keep your home cool and comfortable all summer long.


Before we dive into the specifics of why your AC taking long to cool house, there are a few prerequisites you should be aware of. It’s important to understand that troubleshooting AC issues requires a basic knowledge of how your AC system works. This includes an understanding of the various components of your AC and their functions, such as the thermostat, filters, and coils.

Also, you should have certain tools at your disposal. This might include a thermometer to check the temperature, a flashlight to inspect components, and basic cleaning supplies to clean your filters and coils. If your AC taking longer to cool house, you might also need to consider professional help, especially for complex issues like refrigerant leaks or upgrading your AC system.

Remember, safety is paramount when dealing with electrical appliances. Always turn off the power to your AC unit before starting any maintenance tasks. Now that you’re prepared, let’s move on to the step-by-step instructions to solve the problem of your AC taking long to cool house.

Fix AC Taking Long to Cool House

Incorrect Thermostat Settings

One of the most common reasons for your AC taking long to cool house is simply incorrect thermostat settings. The thermostat is the control system for your AC, and if it isn’t set correctly, it could cause your AC to run inefficiently or not cool your house properly.

Ordered Steps:

  1. Check your thermostat’s temperature setting: Ensure it’s set at a temperature that’s lower than the current room temperature. If it’s set above room temperature, your AC will indeed take too long to cool your house.
  2. Verify the programmed schedule: Some thermostats allow you to set a specific schedule for your AC to follow. Make sure it’s programmed properly to cool your house during the hottest parts of the day.
  3. Check the mode: Ensure the thermostat is set to “cool” mode. If it’s set to “heat” or “fan only,” your AC will not cool your house.
  4. Ensure the thermostat’s location isn’t influencing its readings: If your thermostat is located near a heat source (like a sunny window or a kitchen), it might read the room temperature as higher than it actually is, causing your AC to run continuously.
  5. Reset your thermostat: If all the settings seem correct but your AC is still taking too long to cool the house, try resetting your thermostat. Refer to the manufacturer’s instructions on how to do this.

By following these steps, you can ensure your thermostat settings are correct and optimal for cooling your house efficiently.

Improper schedule programmed on thermostat

One of the most common reasons why your AC might be taking long to cool house is due to an improperly programmed thermostat schedule. Simply put, your air conditioner might not be operating when it needs to, resulting in a warmer home. Thankfully, this can be easily fixed by adjusting your thermostat’s settings.

Steps to Adjust Your Thermostat Schedule:

  1. Find your thermostat’s programming settings: Depending on your thermostat model, this could be a button labeled ‘Program’ or ‘Set’. Consult your thermostat’s manual if you’re unsure.
  2. Set your desired temperatures: Ideally, your home should be cooler during times when you’re at home and awake, and slightly warmer when you’re away or asleep. Make sure to set these temperatures for both weekdays and weekends.
  3. Set your AC to start cooling before you get home: If your AC is taking too long to cool house when you get home from work, try setting it to start cooling 30 minutes to an hour before you usually arrive home.
  4. Review and confirm your settings: After setting your schedule, review it to ensure it aligns with your routine. Then, confirm your settings to save them.

Remember, every home and AC unit is different. You may need to experiment with different settings before finding the perfect schedule for your needs.

Misconfigured Thermostat

A common yet often overlooked reason for your AC taking long to cool house could be a simple misconfiguration in your thermostat settings. The thermostat is the control system for your air conditioning unit, and even minor errors in its setup can impact the cooling efficiency of your AC.

If you’re experiencing this issue, follow these ordered steps to check and correct your thermostat configuration:

  1. Check the Thermostat Mode: Ensure your thermostat is set to “cool” mode. If it’s set to “heat” or “off”, your AC will not cool your house effectively.
  2. Verify the Temperature Setting: The set temperature should be lower than the current room temperature for the AC to kick in and start cooling.
  3. Check the Fan Setting: If the fan is set to “on”, it will run continuously, even when the AC isn’t actively cooling. This might make you feel like the AC is taking too long to cool the house. Set the fan to “auto” so that it only runs when the AC is cooling.
  4. Ensure Proper Power Supply: Make sure your thermostat has a proper power source. Some models require batteries, so check if they need replacement.

If you have followed these steps and your AC is still taking a long time to cool the house, it might be time to consider an AC upgrade. Upgrading your system can provide more efficient cooling and ultimately save you money in long-term energy costs.

A dirty air filter

One of the most common reasons for an AC taking long to cool house is a dirty air filter. A clogged air filter restricts airflow, causing your air conditioning unit to work harder and longer than necessary to cool your home. Regular AC maintenance, especially keeping your air filter clean, is crucial for optimal cooling efficiency.

Steps to Clean or Replace a Dirty Air Filter

  1. Turn Off Your AC: Always start by turning off your air conditioner. This ensures your safety as you work on the unit.
  2. Locate the Air Filter: In most cases, the air filter is found in the return air duct or blower compartment. Consult your AC’s manual if you have trouble finding it.
  3. Check the Air Filter: Once located, check the air filter. If it’s covered in dust and dirt, it’s time for a clean-up or replacement.
  4. Clean or Replace the Filter: If your air filter is reusable, clean it using a mild detergent and warm water. Allow it to dry completely before reinstalling. If your air filter is disposable, replace it with a new one of the same size.
  5. Reinstall the Air Filter: Make sure to reinstall the air filter correctly. An improperly installed filter can cause the same problems as a dirty one.
  6. Turn On Your AC: After the filter is dry and properly placed, turn your AC back on. You should notice an improvement in your unit’s cooling efficiency.

Remember to perform this AC maintenance task at least once a month during cooling season, or more often if your home is particularly dusty or you have pets. A clean air filter can significantly reduce the time your AC takes to cool your house.

Dirty condenser or evaporator coil

One major reason behind your AC taking long to cool house could be a dirty condenser or evaporator coil. As a vital component of your cooling system, these coils work by absorbing the heat from your home’s air. Over time, they can get clogged with dust and debris, reducing their efficiency and forcing your AC to work harder, resulting in it taking longer to cool your house.

Here are the step-by-step instructions for cleaning your condenser and evaporator coils:

  1. Turn off your AC: Always ensure your safety first by turning off the power to your AC unit.
  2. Locate the coils: The condenser coil is usually located outside, while the evaporator coil is inside your AC unit. Refer to your AC’s manual if you’re unsure.
  3. Inspect the coils: Check for visible signs of dirt and debris. If they look dirty, they likely need to be cleaned.
  4. Use a coil cleaner: Purchase a commercial coil cleaner and follow the instructions on the bottle. Spray it on the coils, wait for the recommended time, and then rinse it off.
  5. Clean the area around the outdoor coil: Remove any debris around the outdoor coil, such as leaves or grass, which can impede airflow.
  6. Check the fins: The fins on the coils should be straight. If they’re bent, you can use a fin comb to straighten them.

Remember, regular AC maintenance is crucial to keep your unit running effectively and efficiently. Cleaning your coils is just one part of this maintenance. If you’re not comfortable doing it yourself, consider hiring a professional.

Leaky ducts

Is your AC taking long to cool your house? This common issue could be caused by various factors, one of which may be leaky ducts. When your air conditioning unit’s ducts are leaking, they fail to efficiently deliver chilled air to all areas of your house, thus extending the cooling time. This article will provide you with a step-by-step guide on how to diagnose and repair leaky AC ducts to help you restore your home’s comfort efficiently.

Ordered Steps:

  1. Identify Leaky Ducts: The first step in this process is to identify if you have leaky ducts. This can be done by feeling around the ducts for air leaks, or by using a smoke pencil to visually identify air movement.
  2. Inspect Duct Insulation: If your ducts are not properly insulated, they may be leaking air. Inspect the duct insulation for any signs of wear and tear.
  3. Seal the Leaks: Once you’ve identified the leaks, use a duct sealant to seal them. Apply the sealant around the duct joints and anywhere else you’ve noticed air leaks.
  4. Check the Performance: After sealing the leaks, run your AC and check if the cooling time has improved.
  5. Seek Professional Help: If the issue persists, it may be time to call in a professional. Leaky ducts can be challenging to fix if they are located in hard-to-reach areas. A professional HVAC technician will have the necessary tools and expertise to properly seal the ducts and improve your AC’s cooling performance.

Remember, if your AC is taking too long to cool your house, it may not always be an issue with the ducts. Other factors such as a dirty air filter, misconfigured thermostat, or an old AC can also affect your AC’s cooling performance. It’s essential to diagnose the problem correctly to apply the most effective solution.

A refrigerant leak

Is your AC taking long to cool house? One of the possible reasons could be a refrigerant leak. In this guide, we’ll show you how to identify, troubleshoot, and resolve the issue to restore your AC’s cooling efficiency.

Ordered Steps:

  1. Identify the Problem: The first step is to verify that a refrigerant leak is the issue. If your AC taking long to cool house, and you’ve noticed a sudden increase in your energy bills or the presence of ice on the AC unit, these could be signs of a refrigerant leak.
  2. Call a Professional: A refrigerant leak is not a DIY job. It involves handling substances that could be harmful if not handled correctly. Therefore, it’s best to call a professional HVAC technician who has the necessary tools and expertise to handle the job.
  3. Diagnose and Repair: The HVAC technician will conduct a thorough inspection of your AC unit to confirm the presence of a refrigerant leak. They’ll use specialized tools to locate the leak and repair it.
  4. Recharge the Refrigerant: Once the leak has been repaired, the technician will recharge your AC with the appropriate amount of refrigerant. This step is crucial as undercharging or overcharging can affect the efficiency of your AC.
  5. Test the AC: After the refrigerant has been recharged, the technician will test the AC to ensure it’s cooling your house effectively.

Remember to monitor your AC’s performance after the repair. If it’s still taking long to cool your house, there may be other underlying issues that need to be addressed.

AC Is Too Small

ac taking long to cool house

In the heat of the summer, the last thing you want is an AC taking long to cool house. One common cause of this issue is having an air conditioning unit that is too small for your living space. Just like a shoe that’s a size too small, an undersized AC will struggle to perform its job effectively and efficiently. This could result in not only a hot and uncomfortable home but also skyrocketing energy bills.

Ordered Steps

  1. Evaluate Your Current Situation: The first step is to assess how your AC performs. If you find that your AC is running continuously but still not cooling your house adequately, it might be too small for your space.
  2. Check Your AC’s BTU Rating: BTU (British Thermal Units) is the measurement used to determine the cooling capacity of an AC. If the BTU rating of your AC is too low for your home’s size, it might be the root cause of your AC taking too long to cool your house.
  3. Consult a Professional: If you suspect your AC is too small, consult a professional HVAC technician. They can perform an accurate load calculation to determine the right size of AC unit for your home.
  4. Consider an AC Upgrade: If it’s confirmed that your AC unit is too small, consider an AC upgrade. A correctly sized unit will not only cool your home faster but also work more efficiently, saving you money on energy bills in the long run.

By correctly identifying and addressing the issue of an undersized AC, you can improve your home’s comfort and reduce energy consumption. Remember that an AC upgrade is a significant investment, so it’s best to consult with a professional to make the right choice.

An old AC

Are you constantly asking yourself, “Why is my AC taking long to cool house?” If yes, you’re not alone. Many homeowners face this issue, especially during the hot summer months. One of the reasons could be that your AC unit is old and not as efficient as it used to be. This article will shed light on how an old AC can influence the cooling efficiency of your house and provide some steps on how to deal with this issue.

Steps To Handle an Old AC Taking Long to Cool House

  1. Assess the Age of Your AC: The first step is to determine how old your AC unit is. Typically, an AC unit’s lifespan is about 10-15 years. If your AC is within this range or older, it might be the reason for the slow cooling.
  2. Check for Reduced Efficiency: An old AC unit often works harder to provide the same cooling effect. This reduced efficiency can be seen in higher power bills and longer cooling times.
  3. Schedule a Professional Inspection: If you suspect your AC’s age is affecting its performance, schedule an inspection with a professional HVAC technician. They can assess your unit’s condition and suggest if a repair or replacement is needed.
  4. Consider an AC Upgrade: If your AC is significantly old and repairs are not cost-effective, consider upgrading to a new, energy-efficient model. This can drastically reduce the time your AC takes to cool your house and save on energy bills.
  5. Implement Regular AC Maintenance: Whether you choose to repair or replace your old AC, regular maintenance is key to efficient performance. This includes cleaning or replacing filters, checking for leaks, and ensuring the system is not overworked.

Remember, an old AC taking long to cool house is not just an inconvenience, but it could also mean higher energy consumption. Understanding the problem and taking the right steps can help improve your AC’s performance and your home’s comfort.

Tips and Warnings

ac taking long to cool house
  1. Monitor your AC’s performance: If you notice your “ac taking long to cool house”, it could indicate a potential problem. Regularly monitoring your AC’s performance can help detect issues early, thus preventing major problems in the future.
  2. Avoid DIY for complex issues: While you can handle tasks such as cleaning filters or adjusting thermostat settings on your own, more complex issues like refrigerant leaks or issues with the condenser coil should be handled by a professional. Attempting DIY repairs on these parts can cause more harm than good.
  3. Regular maintenance is key: Regular AC maintenance is crucial to prevent your “ac taking too long to cool house”. It helps to maintain the efficiency of the system and prolongs its lifespan.
  4. Upgrade if necessary: If your AC is old and constantly taking longer to cool the house, it might be time for an “AC Upgrade”. Newer models are more energy-efficient and work more effectively.
  5. Right sizing is crucial: If your “AC is too small”, it could be why your “ac is taking longer to cool house”. Always choose an AC size that is appropriate for the size of your home.
  6. Check for leaks: Leaky ducts can result in loss of cool air, causing your AC to take longer to cool your house. Regularly check for any leaks and get them repaired immediately.
  7. Thermostat settings: Incorrect thermostat settings can also be a reason why your “ac is taking longer to cool house”. Always ensure to set it to the right temperature and mode for optimal cooling.
  8. Cleanliness is essential: A dirty filter or a dirty condenser or evaporator coil can impact the AC’s efficiency. Regular cleaning and maintenance can prevent your “ac from taking long to cool house”.

Remember, if you are unsure or uncomfortable performing any AC maintenance tasks, it’s always safer to call a professional. Regular “AC Maintenance” can save you from expensive repairs in the long run.


ac taking long to cool house

In conclusion, there can be various reasons why your AC is taking long to cool the house. It could be due to simple issues like incorrect thermostat settings or improper scheduling, or more complex problems like a refrigerant leak or an old AC unit. While some issues can be handled personally with regular maintenance, it’s important to consult with a professional for more complex problems. With a well-maintained and properly functioning AC, your house will be a cool haven, no matter how hot it gets outside. Remember, regular AC maintenance is key to preventing issues that lead to your AC taking longer to cool your house.

Frequently Asked Questions

How long should an AC take to cool a house?

Ideally, a well-maintained AC unit should take around 15-20 minutes to cool your house. If your AC is taking long to cool house, it may be due to several reasons like dirty filters, improper thermostat settings, or the need for an AC upgrade. It’s important to identify and rectify the issue for efficient cooling.

What happens if AC coils are dirty?

If the AC coils are dirty, it can severely affect the cooling performance, causing the AC to take longer to cool the house. The dirt and debris build-up reduce the system’s ability to absorb and expel heat, causing the system to work harder and longer to cool your home, leading to increased energy costs and potential damage to the AC unit.

Can you clean AC coils without removing?

Yes, you can clean the AC coils without removing them. This is part of regular AC maintenance. However, it’s crucial to ensure that the cleaning process is done correctly to avoid any damage. If you are unsure, it’s best to hire a professional.

What is the importance of regular AC maintenance and how often should I schedule it?

Regular AC maintenance is essential as it improves the efficiency and longevity of your unit. If your AC is taking too long to cool the house, it may be due to lack of maintenance. It’s recommended to schedule maintenance at least once a year, preferably before the start of the cooling season.

What regular maintenance tasks can I perform to improve my AC’s cooling performance?

Regular tasks to improve your AC’s cooling performance include cleaning or replacing the air filter, cleaning the AC coils, checking for refrigerant leaks, and ensuring the correct thermostat settings. These tasks can prevent your AC from taking too long to cool your house. Regular maintenance will help in detecting potential issues early and fixing them before they escalate.

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