Should you run your A/C when it's cool outside?

June is off to a great comfort start with temperatures in the 70's and low 80's by day and 50's at night! Add a low relative humidity of about 47% and you're set for perfect outdoor weather for most folks.  We won't complain about temperatures like these, but, what about your air conditioners? You want to keep the house cool and comfortable during warm days but running your air conditioner when the temperatures outside drop below 60 degrees can be problematic.

Air conditioners are designed to operate with an assumption that it would never run below a certain outdoor temperature - the "design" temperature. The minimum can vary between models, but it is usually 58 to 60 degrees. 

The air conditioner manipulates the properties of the refrigerant between a gas and liquid to cool the home.  When outdoor temperatures drop below the design temperature, the refrigerant reacts to this change and behaves differently. The air conditioner may keep running, but not without creating an added strain on the system.  This can cause the indoor coil to freeze up as well as the refrigerant lines.  This all puts the primary -  and most expensive to replace component -  the compressor under added stress to perform its function.  Over time, the compressor will fail if it is continually operating under low ambient conditions without the necessary components in place to prevent such failure.

It's hard to say how long a unit can operate in low ambient conditions before compressor failure.  But really, who wants to take that gamble if it can be avoided?

What is a low ambient condition?

In the HVAC industry, outdoor low temperatures are referred to as low ambient conditions. 

In many commercial applications, like manufacturing facilities and buildings with high occupancy, the HVAC system has to operate  when temperatures outside are cooler than 60 degrees because of the added heat gain for the conditions. The units are either of special design or a component is added called a "low ambient kit" to assist the unit with operation to safeguard the compressor.  So, it is not out of the question for your home's air conditioner to run without problems when outdoor temperatures drop.  You just need to make sure the low ambient component is added to safeguard the compressor.

In most cases, especially in residential applications, you should not run your air conditioner when outdoor temperatures are below 60 degrees.  The air conditioner does function, but you are going to burn out the compressor fairly quickly.  Our team is ready to assist you if you would like to continue running your air conditioner during cool temperatures outside.  The cost of adding a low ambient kit to your system varies but should run below $300.00.  Each air conditioner and application is different and whether a kit can be added would depend on the manufacturer. 

Call us for more details. We are ready to help make sure you are comfortable inside.