Rain alone will typically not affect an air conditioning unit, as they are built to perform outdoors. However, heavy precipitation can cause flooding or deep-standing water that can damage the internal components of the outdoor unit.
It is important to make sure your air-con unit is located in a position that is not susceptible to water build-up to ensure its longevity. Strong winds and debris associated with storms can also cause damage, such as knocking debris into the condenser grill or unhinging improperly installed units.
To minimise rain damage during a very heavy storm, it's advisable to place a barrier of protection, such as a board, around the unit to prevent leaf, dirt, and sand build-up.
If there is an unpredictable storm and you cannot protect the unit, a professional inspection is recommended to ensure no damage has been done.
Is lots of rain going to affect my air conditioner?
Typically, rain alone will not affect an air conditioner unit as the system’s outdoor units are built to perform in all weather conditions. However, it is often thought that heavy precipitation can cause water to seep into your air conditioner and damage the internal components. We have, for example, seen heavily corroded condenser coils in units that regularly had a sprinkler soak them with water.
However, an air conditioner’s internal components are usually resilient to water. Occasionally, rainwater and being sprayed with a sprinkler or hose won’t affect your air conditioner unit’s functionality or performance.
When can water pose a threat to my air conditioner system?
However, water can adversely affect an air conditioning unit when there is a flood or deep-standing water entering the moving components and circuits of the unit. Any flooding or flash flooding of around 40cm can submerge the condensing unit of an air conditioner located on a flat ground-level surface. This can then ultimately lead to a malfunction in the form of a short circuit. Placing outdoor units on brackets at a height in such locations where flooding could occur is advised.
Of course, all units are different. Most are placed where water build-up is negligible. However, ensuring your unit is in a position not susceptible to water build-up is of high importance to ensure the long life of your unit.
Suppose your unit has been submerged after a flooding incident. In that case, we recommend contacting a certified HVAC contractor once the water recedes. Ensuring the water build-up has exited the unit and determining the damage level.
Moisture in the air
Heavy rain increases the moisture in the air. Some customers might think that there is more moisture in the air and that air-conditioning units use air from outside. They could carry more moist air into the home. Luckily they are designed to remove moisture from the air, so this fear is unfounded, and the air arriving on the inside will be comfortable and will not add to the humidity in the home. The units on certain settings can remove moisture-heavy air from the home.
Debris can also damage the air conditioner unit
Heavy rains do not vastly affect an air conditioner unit, although the winds and gales associated with storms can knock debris into the condenser grill. Especially twigs, dirt, and dead leaves can sometimes find their way into the unit. In addition, strong winds can knock branches onto a unit, causing dents. We have even seen improperly installed units becoming loose. With winds pushing them on their side.
Therefore take steps such as ensuring your unit is properly secured. The unit is not in a water catchment position and is thus susceptible to flooding. Make sure your unit is not in a catchment area for falling debris. For example, regularly check for overhanging tree branches near your air conditioner unit and trim those back regularly. All these steps will ensure that your air-conditioning unit is best protected if located in an area prone to heavy rains and storms.
Ways to reduce rain damage
Some believe covering an air conditioning unit is an appropriate solution to counter excess rain or dirt build-up. However, covers and tarps can trap moisture within an air conditioner.
This can cause mildew and mould and lead to rust and corrosion within the key parts of the unit. Especially the coils and motherboard. Therefore we firmly believe that a cover is not needed as systems are durably built for the rugged outdoor conditions of Australia and New Zealand. If you feel you must use a cover during powerful rain. It must be removed immediately after the storm has subsided.
To avoid leaf, dirt, and sand entering the unit in case of a windy storm in homes near forests and outback deserts. You could place a board anywhere from 40cm away to protect against these fundamental factors.
Suppose there is a sudden storm, and you cannot get protection over the unit. In that case, it is advised that you get a professional inspection completed after the worst is over to ensure no damage is done.