The right type of HVAC pad to support the outdoor unit of your central air conditioner is important for proper cooling function and maximum service life. The central AC outdoor unit incorporates critical parts such as the AC compressor motor and the condenser coil, as well as high-voltage electrical components and switches. Because the outdoor component of a central air outdoor unit for a typical home weighs between 150 and 200 pounds, it requires secure mounting on an HVAC pad that’s specifically designed for the purpose.

Never place the outdoor unit directly on the ground. In rainy weather, soil softens and the heavy unit may tip over, breaking refrigerant tubes and damaging the fragile coil. Also, pooling water may flood the unit and ruin parts like the compressor motor, which is typically the most expensive component in the system. 

Is a Poured Concrete HVAC Pad the Best Option?

Not necessarily. Concrete pads are very heavy and typically sink deeper into the soil over time. As the pad sinks and slants, the outdoor AC unit may potentially tip over. Concrete may also eventually crack due to seasonal freezing and thawing of the ground. Hard concrete is dense and doesn’t absorb vibration produced by the unit in operation, subjecting components like the compressor to potential mechanical deterioration.

What Are Alternate Options for an HVAC Pad?

Composite materials like recycled plastic and rubber are utilized to manufacture prefab pads specifically designed for the size and weight of your air conditioner. Here are some advantages:

  • Synthetic pads are rain- and snowproof and treated to resist UV exposure as well as seasonal temperature changes.
  • A composite HVAC pad can support more than 350 pounds, yet it weighs less than 20 pounds. Thus, it is less likely to sink into soil than heavy concrete.
  • Composite materials absorb vibrations more effectively than hard concrete, reducing vibration-related wear and tear on AC components.
  • Synthetic pads are manufactured to comply with local code requirements for size and thickness. 

For more about making the right choice when it comes to selecting an HVAC pad, talk to the experts at Mowery Heating, Cooling and Plumbing.