Effect of Ambient Temperature On Air Conditioning


With temperatures rising at unprecedented rates and the global climate becoming hotter, life without air conditioning is now unimaginable.

But do these changing ambient temperatures have an impact on air conditioners? Yes, they do – an air conditioner is mostly designed to operate with outside temperatures between the 60°F and 95°F range. Below 60°F, the coils inside the unit can freeze and the unit won’t work as well. And above 95°F, the unit can get overworked and have a hard time achieving the temperature that’s set on the thermostat.


Do Outside Temperatures Affect Air Conditioners?

Air Conditioners are designed to work at high temperatures to normalize internal temperatures. They are made to accommodates up to a 30°F difference between internal and external temperatures. Beyond that and air conditioners struggle to keep a home cool.

For this reason, most air conditioners are built to work under 100°F and push to their maximum capacity when the outside temperatures reach about 95°F.

Anything higher than that can, in fact, cause great damage to your HVAC system. This is because when your air conditioner is continually running, air filters can become clogged, the fans accumulate debris faster, the unit gets overheated, and more electric input is required to effectively perform.

So, beyond peaks in your electrical bills, a brutal summer month can also bring damage to your air conditioner.

Just as higher temperatures decrease air conditioner performance, ambient or lower temperatures can also do to. That is because at lower temperatures, your air conditioner starts working harder to produce a noticeable change. Typically below 60°F is when an air conditioner cannot operate.

Recommended Reading: Does Outside Temperature Affect Air Conditioner?


Will Lowering the Thermostat Improve Cooling Performance?

One of the most common misconceptions is that lowering the thermostat would improve the cooling performance of an air conditioner. The idea being that somehow an air conditioner would be more efficient and work for less time. In fact the reality is quite different. 

Not only would this drive up your utility bills but would be highly inefficient. An average air conditioner takes the same amount of time to reach 75°F whether you set it at 72°F or 75°F.

Another thing also to consider is that at lower temperatures, the air conditioner compressors works for longer, consuming more power. During a hot summer month, expecting too much from your compressor can overwork and break it down.

This extra work is reflected in your electricity bill. A one degree increase in AC temperature can translates to a difference of about 3 to 5% in electricity.


What Temperature Should I Set My Thermostat To?

On the hottest days, when the thermometer approaches 100 degrees, it is recommended to set your air conditioner to between 75 and 80 degrees.

You can also supplement your air conditioner’s performance by changing your physical surroundings yourself. For example, you could keep the curtains on the sunny side of your house closed, install extra fans to help out, cross ventilate early in the morning, add a dehumidifier to help extract the summer moisture to help the HVAC system work less, and even to try cook outside instead of inside.

Avoid random and constant changes to the thermostat as it will not only decrease efficiency.

Instead, perhaps invest in a programmable thermostat that controls the temperatures for you, especially when you’re away from work.

This one is said to help you save up to 23% on your HVAC’s energy:


How to Increase Air Conditioning Efficiency?

Air conditioners are are probably the one thing we absolutely can’t live without in our homes, especially in the summer. Yet, we tend to forget and neglect it until it breaks down.

In fact, most households do not even consider having a preventative service check-up or setting up a maintenance routine until its too late and its cooling performance is significantly decreased.

Here’s some things you can do to maintain, and possibly increase your air conditioner’s efficiency:

  • Cover the top of the external unit in the fall/winter if not in use. Especially if it’s near trees with falling leaves, pinestraw, or other debris.
  • Protect the external unit by using a wire enclosure or locking it. Raise it by having it on a concrete platform instead of a loose foundation.
  • Clean the compressor. This can be done by simply running a water hose over it and spraying the coils with coil cleaner.
  • Regularly dust the air filters. Better yet, replace them.
  • Keep the external unit under shade but away from humidity. 
  • Have an annual maintenance that involves cleaning the unit and replacing any of the faulty parts. 
  • Keep the thermostat at higher temperatures whenever possible so the unit doesn’t get overworked.


Related Questions

How do Air Conditioners Work? 

Air conditioners change temperatures, humidity and air quality by removing heat energy from within a house, transferring it outdoors, and replacing it with cooler air.

The evaporator involves the use of cooling cols to remove the heat and humidity, then the blower circulates the air over the evaporator allowing it to be dispersed and removing the hot air. Finally, the compressor moves the refrigerant between the evaporator and the condenser to cool the air. 


Are There Cheaper Alternatives to Air Conditioners? 

While there are different types of air conditioners available in the market, many often complain of the high cost of the unit as well as its use and maintenance. Cheaper alternatives to central air conditioners include: window air conditioners, portable air conditioners, evaporative air coolers, room fans, whole house fans and mini or ductless air conditioners.

While these may not be as aesthetic or as powerful as air conditioners that are part of an HVAC system, they do often provide decent results.