cold weather climate acIn cold-weather climates, the question sometimes comes up: Can I run my air conditioner when it’s still cool outside? Some homeowners want to activate the AC during cooler weather to maintain air circulation and filtration in order to sustain indoor air quality. Or, the resident may simply want to test the air conditioner on a chilly day.

Even when outdoor temperatures are rising, in some cases, the outdoor component of the central AC may be located in a shaded spot where it doesn’t receive warmth from the sun on a very cool day. Whatever the scenario may be, here are some factors to consider before you start the AC in cold-weather climates.

  • Air conditioners are engineered and constructed to run in warmer outdoor temperatures—generally not much lower than 60 degrees. Because of the potential for damage, many HVAC service technicians, as well as professional home inspectors, will not operate a central air conditioner in outdoor temperatures below 55 degrees, even for the purpose of testing.
  • Oil protecting the system compressor in the outdoor unit is a heavy grade. At cooler temperatures (below 60 degrees), oil begins to thicken and may not properly lubricate the compressor. Since the compressor is generally the most expensive single component in a central air conditioner, excess wear and tear caused by inadequate lubrication is a very negative possibility.
  • In some AC units, the refrigerant gas in the system may turn to liquid and pool inside the compressor if it is subjected to outdoor temperatures below 55 degrees. The compressor is designed to compress a vapor, not a liquid. If the temperature of the outdoor unit has not warmed above 55 degrees when the unit is started, expensive damage to the compressor may result.
  • Operating instructions for most central air conditioners typically include a cautionary statement such as, “The outdoor unit of your air conditioner is not designed to operate when outdoor temperatures are below 55 degrees Fahrenheit.”

For more advice about running your central air conditioner in cold-weather climates, contact the professionals at Mowery Heating, Cooling and Plumbing.