Although most outdoor HVAC units are designed to resist extreme weather, flooding can damage your air conditioning unit in unforeseen ways that require immediate attention. With the increased risk of flooding from rapid snowmelt, a dam failure, or the Missouri River itself, South Dakota residents need to stay aware of the dangers flooding can create for their HVAC units.

Three parts make up your air conditioner system: the external compressor/condensing unit, the duct work inside your building, and the internal air handler system. Except in rare and extremely devastating situations, your ductwork and internal air handling system are shielded from the effects of most floods. However, your external air conditioning unit is completely exposed to flood waters and the damage they can cause.

Let’s examine in greater detail how a flood can impact your outdoor HVAC unit.


Damage to Your Air Conditioning Condenser Pad

Nearly every outdoor HVAC unit sits on a pad that keeps it level and off the ground. This structure is referred to as an AC condenser pad, and it serves several functions. First, it keeps your air conditioner away from moisture and ground pests that would like to take up residence inside the unit. However, the main job of the AC condenser pad is to keep your air conditioner in a stable, level position and reduce movement of the unit due to vibration. An AC unit that is not level will force the fan shaft to sit at an incorrect angle. This can cause the air conditioner unit to run noisily and result in early fan failure.

While most AC condenser pads are waterproof, flooding can cause several issues that your pad is not equipped to handle. Soil erosion surrounding your air conditioner unit is the primary concern, as flood waters can wash away soil around or underneath your condenser pad. At a minimum, your condenser pad will not be level after a flood. In extreme cases the air conditioner unit can partially or completely wash off from its condenser pad. If either of these situations occur, turn off your air conditioner immediately and do not operate it until the unit is once again level and on solid footing.


Flooding and heavy winds may force debris into your outdoor air conditioner unit. This is a serious problem, as debris inside the air conditioner can damage the fan blades or other internal portions of the unit. Having your air conditioner serviced by one of our certified Haugan HVAC technicians after a flood is critical to maintaining your unit and preventing potential damage that might cause your AC to fail prematurely.


Standing Water in Your AC Unit

Standing water in or around your outdoor air conditioner presents several dangerous situations that can permanently damage the internal components of your unit. If water seeps into your HVAC unit, it can damage the system as well as other parts of your home. Standing flood water is a breeding ground for bacteria like E. coli as well as mold, tetanus, and other nasty bugs that you don’t want anywhere near your home. These pathogens can become airborne if the unit is turned back on, posing a serious health threat to your family.

Standing flood water in your outdoor HVAC unit creates numerous mechanical and electrical issues as well. Although the circuitry of your air conditioner is shielded from the elements, standing water in your HVAC system can damage its electrical components. The fan and other parts of your unit can also become damaged. Rust and corrosion are also an issue, as your air conditioner is not designed for submersion in water for any extended period of time. In the event that a flood does submerge part or all of your outdoor air conditioner unit, it is likely the unit will require replacement.


Should You Cover Your Outdoor Air Conditioner Unit Prior to a Storm?

It might seem like a good idea to cover your outdoor air conditioner unit with a tarp or plastic bag prior to severe weather – but you should NOT do this. Covering your air conditioner will trap moisture inside your unit, making it extremely attractive to bacteria and outdoor pests. Trapped water will also accelerate corrosion of the internal components of your AC unit. If your outdoor unit is turned on while still covered, its compressor will likely become damaged as the result.


What Should You Do With Your Outdoor HVAC System After a Flood?

If you’ve experienced a flood in your area, do not turn your HVAC system on until it has been properly inspected and serviced by one of our qualified HVAC technicians. The experts at Haugan Heating & Air Conditioning have proudly served the Sioux Falls, SD area for over 50 years and we stand ready to take care of all your air handling needs before or after any natural disaster.