Does turning the thermostat down make it colder?

Author: Marquise Kunze DDS  |  Last update: Sunday, March 15, 2026

Setting your thermostat low doesn't cool your home faster But setting the thermostat really low doesn't increase your air conditioner's cooling capacity. “People think, 'If I make the thermostat set point 60, I'll get more cooling than a set point at 70,' but that's not correct,” Liu said.

Do you turn the thermostat up or down to make it colder?

HVAC experts will tell you all the same thing: turning your thermostat to a lower setting DOES NOT cool your home faster.

How cool should my house be if it's 100 outside?

When temperatures exceed 100 degrees Fahrenheit outside, setting your air conditioning (AC) to around 75-78 degrees Fahrenheit is generally considered efficient. Here are some reasons for this recommendation:

Is 72 too high for a thermostat in winter?

68 to 72 degrees is a temperature range that is not too warm or cool, and is sufficient enough to warm up the home just enough so that everyone is comfortable regardless of the type of clothing they have on.

Is lower thermostat colder?

Lowering the temperature on the thermostat results in your central air system working longer and harder until the overall temperature of the home reaches the set temperature; it does not necessarily result in colder or faster air conditioning.

How Thermostat Setbacks Save Money | Ask This Old House

Is it better to set your thermostat higher or lower?

Energy.gov suggests that 68 degrees is a good room temperature while you're awake at home but recommends lowering it while you're asleep or away. Lowering your thermostat 7-10 degrees for eight hours a day can reduce your annual heating expenses by as much as 10 percent.

Is running AC at 68 bad?

Set a reasonable temperature: HVAC professionals strongly recommend never setting the thermostat lower than 68 degrees in the summer. To balance comfort and energy efficiency, the Environmental Protection Agency recommends setting your thermostat to 78 degrees when you're at home and awake.

Why does my house feel cold at 72?

If you're cold even though your thermostat indicates you shouldn't be, your furnace likely isn't the problem. In most cases, it's working just fine. It's your home that needs attention. Lack of insulation, severe air leakage, and/or unbalanced ductwork are frequently to blame.

Is 82 too high for AC?

While ENERGY STAR suggests 82 degrees, that may be too uncomfortable for most families. Most people sleep better when their sleeping area is chilly, so that's why the National Sleep Foundation advises 60–67 degrees.

Does keeping the AC at 72 save money?

Best AC Temperature Settings While You Are Home

As you consider the most comfortable room temperature for your lifestyle and family, keep in mind that for each degree that you set your thermostat above 72 degrees, you can save up to 3% on your energy bill.

How cool should my house be if it's 110 outside in summer?

Just because the outdoor temperature is above 100, the Ideal temperature to set your AC unit to doesn't change — it's 78 degrees. Higher temperatures in the home are to be expected when the weather is hotter than usual, but your thermostat can still be set the same as if it were a lower temperature outside.

How long should it take to cool a house from 90 to 72?

Cooling a house from 90 degrees to 72 degrees typically takes about 2 to 4 hours, depending on various factors.

What should I set my AC to on a 100 degree day?

For the most efficient performance, set the thermostat 20 degrees lower than the temperature outside. On a 100℉ day, set it to 78℉ to 80℉ to manage utility costs. If there's a lack of airflow, the filter may need to be changed or AC vents cleaned. But it may also mean your air conditioner needs professional repair.

What number makes AC cold?

Setting your AC to 16°C will cool the room more than setting it to 30°C. However, keep in mind that extremely low temperatures can lead to higher energy consumption and may not be comfortable for occupants. A moderate setting, like around 22–24°C, is often recommended for both comfort and efficiency.

Does turning the thermostat down really save?

Thermostat Operation

You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7°-10°F for 8 hours a day from its normal setting. The percentage of savings from setback is greater for buildings in milder climates than for those in more severe climates.

How do I make my AC colder?

How to Make Air Conditioners Colder?
  1. Clean and change the air filter as needed,
  2. Conduct regular AC maintenance or call in a professional to help you,
  3. Use blinds and heavy curtains to keep direct sunlight out of your home,
  4. Check the air seal around your window air conditioner,

Why is my AC set to 72 but reads 78?

Clean the Thermostat

Sometimes, when the room temperature doesn't match the thermostat setting, the problem could be dirt buildup on its interior parts. A dirt coating around the inner components may create excess heat and cause the thermostat to give the wrong readings.

What should I set my AC to in summer?

What is the Best Thermostat Setting for Summer Air Conditioner Use? Energy Star recommends the following thermostat temperatures for your air conditioner in the summer: 78°F during the day if people are home. 82°F at night if people are home.

Should my thermostat be on run or hold?

The best way to save money is by combining both. The “run” feature lets you preset the temperature when you're not home to prevent wasting money on cooling or heating an empty home. Meanwhile, the “hold” button lets you change the room's temperature without changing your energy-saving, preset schedule.

Is it bad to run AC at 72?

Setting your air conditioning to 72°F is generally considered a comfortable indoor temperature for many people. It strikes a good balance between comfort and energy efficiency, making it a popular choice for residential settings.

What is the most comfortable temperature to keep your house?

In general, the ideal room temperature and your home for both efficiency and comfort fall somewhere between 68° and 76°F. What should the average room temperature be in winter? In the winter, you might choose to keep your thermostat set lower around 68° in order to save energy and dollars on your next heating bill.

Why is it still hot with the AC on?

Low refrigerant levels: Low refrigerant levels can lead to your AC not being able to produce cold air, resulting in hot air being circulated throughout your room. Low refrigerant levels can occur due to regular wear and tear or leakages in the unit.

Do you turn the AC up or down to make it colder?

Most people know that turning up the thermostat on their air conditioner to a higher temperature will result in cooler air blowing from the vents. However, there is a point at which increasing the temperature any further does not make the air cooler – it just uses more energy and costs more money.

Why should people stop setting the thermostat at 72?

Setting your thermostat just a single digit higher can help you save 6 percent on your cooling costs, according to the EPA.

What is the best AC temperature for sleeping?

The best AC temperature for sleeping

The goldilocks zone: Aim for a temperature between 18°C (64°F) and 22°C (72°F) for optimal sleep comfort. Individual needs: Consider personal preferences and adjust the temperature accordingly. Some people may prefer slightly cooler or warmer settings.

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