What to Know About HVAC Systems and RainWith all the precipitation in the forecast, now is a good time to go over the effects of rain on your heating and air conditioning system. Luckily, your outdoor HVAC unit is designed to withstand harsh weather conditions such as rain, snow — even minor hail. Unfortunately, if your unit needs service during extreme weather, you may have to wait for a technician to provide service, especially if it’s located on the roof.

HVAC Design and Weather

Your air conditioner utilizes heat pump technology to pump heat from inside your home to the outdoor environment. Depending on your specific unit, you may have either a traditional air conditioner or a heat pump capable of both heating and cooling.

In the “split” system common to houses all over the United States, one unit (housing the evaporator coil and blower) is located inside and the other (containing the compressor and condenser) is located outside. The outdoor component is specifically designed for years of exposure to a wide range of harsh weather conditions. This is done by sealing electrical components from the rain and employing sturdy, corrosion-proof construction materials, such as copper, aluminum, and extremely durable, custom-formulated plastics.

Despite all this careful engineering precaution, your HVAC system is still vulnerable to damage from falling tree limbs, wind-driven debris and flooding rains. Regular maintenance, which includes thorough cleaning, is the best way to ward off repairs and improve energy efficiency.

Is Your Outdoor HVAC Unit at Risk in the Rain?

Even the heaviest rain will have no measurable effect on the operation of your outdoor HVAC unit. It’s perfectly safe to run your heater or air conditioner while it’s raining or storming outside. Your outdoor unit is really only susceptible to environmental damage when flooding occurs. Should it become submerged, its wiring, electronics, and motor could get damaged. The heat pump can work in the rain, but not in standing water.

If the outdoor unit is partially or fully submerged, turn off the HVAC system at the electrical panel. Have a professional inspect the system before turning it back on again.

Should You Cover the Outdoor Unit?

It is not advisable to cover your outdoor HVAC unit, regardless of type. The condenser inside it has been designed to withstand years of moisture and temperature extremes, and depends on natural ventilation to allow moisture to evaporate before it has to chance to cause corrosion or other damage to its internal components. Some people choose to cover their units in winter to protect the from snow, leaves and debris — but this can do more harm than good. Trapped condensation can destroy equipment, and quickly.

Similarly, do not allow anything to sit on top or within a two-foot radius of your outdoor HVAC unit, especially if it is running. It requires proper airflow in the surrounding area in order to do its work. If you have legitimate concern about debris falling into your unit due to its location, it may be possible for you to build some sort of awning above it, but please confer with a professional HVAC technician first.

Can HVAC Technicians Service Units in the Rain?

As a general rule, technicians do not service outdoor units in the rain. Besides the obvious danger posed by working on electrical components in the rain, opening panels to allow rain directly inside normally-closed parts of the unit could cause further damage. Units located on roofs are even more dangerous, increasing the risk of slip-and-fall injuries and potential exposure to lightning strike.

In emergency situations we may dispatch HVAC technicians to your home during heavy weather, but please understand that we may have no choice but to wait until it clears before endangering our personnel, especially if your equipment is roof-mounted.

If you do happen to notice leaks or signs of water damage on or around your HVAC system, please contact Comfort Systems in Wichita before more damage has the chance to occur.