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Why Doesn’t My Air Conditioner Reach The Second Floor


Do you have an air conditioner at home, but you find it does not cool certain parts of your house?

Similarly, you may face the same challenge in a two-story house with air conditioning that does not cool the second floor.

You may think the solution is to increase the capacity of your current AC unit. However, the problem is not the capacity to cool but the insufficient airflow to your second floor.

Getting a larger unit or buying an AC unit for the second floor adversely affects your house and your pocket.


Having an air conditioning unit that does not work to your family’s standards can be stressful.

You could have a new AC unit that does not evenly or efficiently cool all the rooms. Various reasons could be the cause of such problem, which include:

  1. Too many rooms
  2. Rising heat
  3. The heat from the roof
  4. Outdated or inefficient air conditioner unit
  5. Thermostat set too high
  6. Old, leaky, and inadequate ducts

There are six tips that you can apply to cool down your second floor:

  1. Using floor and ceiling fans that cool smaller areas.
  2. Turning off all lights and unused appliances on the second floor.
  3. Changing air filters.
  4. Insulating attics.
  5. Lowering the thermostat by 2-4 degrees.
  6. Getting heat-blocking shades.

If you do not achieve your family’s standard temperatures after applying the provided tips, you can replace your current air conditioner unit or buy an extra system for your second floor.

Having different temperatures on different floors indicates your Air conditioner unit has issues with how it is working. Sometimes, your air conditioner unit could be outdated. You should replace any unit serving you for more than ten years. You must not necessarily buy a new air conditioner if you can get skilled professional help.

Why Your AC Cools One Floor While Others Remain Too Warm


Most homes use one air conditioner unit that serves all of its structures. One thermostat controls it, and in most cases, it is placed in a common area where people spend most of their time.

When the area gets heated up too much, the air conditioner kicks on and cools the room until the temperatures fall back to the desired range.

Bigger homes, especially those with several floors, require an air conditioner unit with higher capacity.

One air conditioner unit may not be enough for adequate and even distribution of cool air in all rooms of your house.

Also, one AC unit may fail to react effectively to hot air or cold spaces in your house. Your house could also have insulation problems, leaking air ducts, or blocked vents.

6 Reasons Your AC Unit Does Not Cool Your Second Floor

Too Many Rooms


If your house has more rooms than the number the air conditioner unit can take care of, it will be hard for it to cool the second-floor room.

For instance, if your house has four rooms on the first floor and four on the second floor, the total number of rooms is eight, and your air conditioner unit is designed to cool five rooms.

The air conditioner will not evenly or efficiently cool all the rooms. Maybe you bought your AC unit when you had fewer rooms but added more after moving in, yet the cooling capacity remains the same.

Rising Heat


Heat always rises, and if you have placed your air conditioner unit on the first floor, it pushes out the hot air, and a cool one gets in the room.

Therefore, it has to work extra hard to cool the second floor.

The Heat Coming From the Roof


Hot air penetrates your house through the roof and heats the attic unless it is blocked from the sun or deflects rays.

As the air passes through the attic space, your second floor absorbs the heat, making it hard for the AC unit to cool down the rooms.

Outdated or Inefficient AC Unit


If you have been living in your house for over ten years and have never replaced your air conditioner, the AC unit may be outdated and cannot efficiently cool both floors.

Most AC units have a lifespan of 10 to 15 years.

Therefore, replacing your air conditioner unit is vital for better comfort, cleaner air, reducing utility bills, and increasing your home value.

The Thermostat is Set Too High


Setting the temperature too high could be why the second floor of your house is not cooling as it should.

Old, Leaky, and Inadequate Ducts


If you have never replaced your AC unit for over ten years, it is obvious the ducting unit has never been replaced.

Therefore, the duct could be old, leaky, under-insulated or uninsulated, or simply inadequate to cool the second floor of your house.

6 Tips To Cool the Second Floor of Your House

  1. Use floor and ceiling fans to cool smaller areas.
  2. Turn off lights and unused appliances on the second floor.
  3. Get heat-blocking shades for the second floor of your house.
  4. Change air filters. You should change the air filters in your air conditioner unit. Clogged or dirty filters affect air circulation in your house. Most manufacturers recommend you replace air filters regularly.
  5. Insulate Attic. Ensure your attics are properly insulated to minimize the heat that your roof absorbs and eventually enters the second floor.
  6. Reduce the thermostat in a few increments. Lower your thermostat by around 4 degrees and observe if the rooms start to cool off. Keep reducing until you find a setting that works based on your desires. Note the setting somewhere and keep your thermostat there all the time. You must switch the thermostat on from the auto to let the blower fan keep running and mix the air in all rooms of your house.

If there are no changes, even after applying all the tips provided, you can replace your air conditioner unit or get an extra system for your house.

Repairing your faulty air conditioner unit can be an easier fix, but the solution will not sustain your wallet for longer.

You can decide to upgrade the air conditioner unit to a modern energy-efficient unit that will adequately distribute cool air in all rooms of your house.


You could be living in your house for a long time, and you have added more rooms over the period. However, the air conditioner that initially cooled all rooms no longer works efficiently.

Check how many rooms your air conditioner unit is designed to take care of because you could have more rooms.

If you have been using the same air conditioner unit for over ten years, you should upgrade it because most AC systems have a lifespan between 10-15 years.

It could still be good, but there are some reasons for its misbehavior. Check out all the provided issues and fix them.

Follow the provided tips but if it does not meet all your desires, seek professional help or repair it.

However, repairing provides a temporary solution and will incur huge maintenance costs. Upgrading your unit or getting an extra AC unit could be the best solution for your problems.

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