Ideally, there should be a temperature differential of around 14° to 20° Fahrenheit between the incoming air and the air being blown out by your air conditioner. This means that if the air entering the system is 75°F, the air coming out of the vent should be between 55°F and 61°F.
Now, from the example above, with 75 degree air being pulled in at the air filter, what temperature should we expect to be blowing out? Well, the general consensus is somewhere between 14 to 20 degrees colder than the intake temperature. From my example, 55 to 61 degrees would be an acceptable range.
The large copper tubing with the insulation should be cold, while the smaller diameter copper tubing should be warm. When the thermostat calls for cooling, is the outside unit running? The condenser fan on top of the unit should be blowing warm air out the top, and the compressor should be running.
What should my AC be set at if it's 90 degrees outside? If the outdoor temperature is 90 degrees, it's recommended to set your thermostat between 75-78 degrees.
The ideal temperature for your air conditioning at night can vary based on personal comfort, but many experts recommend setting it between 68°F to 72°F (20°C to 22°C) for optimal sleep. This range helps promote better sleep quality while also being energy efficient.
Since 72 degrees is generally agreed upon to be an ideal indoor temperature, most people would probably still feel comfortable setting their AC units slightly higher than this, perhaps at around 75.
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.
Your AC might not cool properly due to thermostat issues, an undersized unit, or extremely high outdoor temps—so check those first. Keep an eye on airflow—replace clogged filters every 3 months, and make sure vents and ducts aren't blocked for efficient cooling.
Most people work better and are more productive when with a temperature setting in the 72–74-degree range. This setting is low enough to keep the house cool and dry and keep you and the kids awake during the afternoon hours.
For many of us, 70 degrees is the ideal indoor temperature, but when it is close to 100 degrees outside, your AC unit will be working quite hard to meet these expectations. Consider setting your thermostat at 75 degrees to 80 degrees in your home if the outside temperature is approaching triple digits.
Ideally, there should be a temperature differential of around 14° to 20° Fahrenheit between the incoming air and the air being blown out by your air conditioner. This means that if the air entering the system is 75°F, the air coming out of the vent should be between 55°F and 61°F.
Without enough refrigerant, the evaporator coil inside your air conditioner gets too cold. As condensation forms, the cold evaporator coil turns this condensation into ice. That's why one of the biggest manifestations of a frozen AC unit is an evaporator coil that's turned into a block of solid ice.
During heat waves, experts, including utility companies, recommend keeping your thermostat no more than 20 degrees cooler than the outdoor temperature. For instance, if it's 100 degrees outside, aim to set your thermostat to at least 80 degrees.
Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air. Why not? Most air conditioning systems can only handle a 20-degree difference between the outside and inside air temperatures.
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.
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.
U.S. Department of Energy research suggests that setting your programmable thermostat to 78 during the summer months is the best way to save money on your cooling costs while maintaining a comfortable temperature.
In short, the 20-degree rule of air conditioning states that you should always keep your AC unit at no more than 20 degrees lower than the outside temperature. It means that, if the outdoor conditions are at 95 degrees, you should set your thermostat at no less than 75 degrees.
Keeping your home at 74 degrees or higher in the summer is a best practice, and turn it up even higher when you're away from home. You should also change your filters regularly (at least once every two months), close the blinds on the sunny side of the house and use ceiling fans (set to a counterclockwise rotation).
Air conditioners make homes more comfortable on hot and humid days. So, it can be frustrating when the AC is not cooling below 75 degrees, even if it has been running for hours. Many factors can cause this issue, including clogged filters, refrigerant leaks and the wrong unit size.
Utilities do their own research, but also have followed the recommendations of a federal program run by the U.S. Environmental Protection Agency and the U.S. Department of Energy, which recommends that thermostats should be set at 78 degrees for comfort and savings. “When it's really hot outside, your AC feels it too.
Dirty filters, blocked ducts, or malfunctioning HVAC components can prevent your system from heating or cooling your home efficiently. Regular maintenance, including cleaning or replacing filters and having your system professionally inspected, can prevent many of these issues.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.