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Should Indiana Homeowners Cover Outdoor HVAC Unit Equipment During Colder Months?

Harsh winter weather conditions including freezing rain, high wind speeds, and snow can put outdoor equipment through the ringer. When it comes to outdoor HVAC units such as an air conditioner or heat pump, many homeowners fear these AC units could sustain damage due to exposure to the elements over the winter months and that outdoor units of the HVAC system require protection. An air conditioner cover can be purchased to protect the entire unit, but is it necessary or advisable to cover your air conditioner?

Before installing air conditioner covers this winter, get trusted advice from heating and air conditioning professionals so you can make an informed decision about caring for the unit that sits outside your house. Williams Comfort Air explains how to best protect your air conditioning unit during the colder months. Learn more about how air conditioning equipment is built and if covering your air conditioner is a necessary step you should take this season. Our pros explain how air conditioners can be affected by the use of an AC cover both over the fall and winter as well as once spring and summer arrive.

Air Conditioning Unit Design

The majority of Central Indiana homes have split system air conditioning units, which means there is an indoor unit as well as an outdoor unit. Some homeowners utilize an indoor furnace paired with an outdoor air conditioner while others have an indoor air handler matched with a heat pump as the outdoor unit.

No matter which type of outdoor unit you have, an air conditioning unit or a heat pump, your AC unit is designed to withstand the elements it is exposed to year-round, whether it be summer or winter. An air conditioner or heat pump is built to tolerate exposure to direct sunlight and extreme weather no matter the season, including heavy rain, wind, and even tree debris that might fall onto the AC unit over the summer, as well as the unique conditions faced during the winter months, such as snow, sleet, and ice.

Air conditioning units and heat pumps are built using durable materials that are water-resistant and are not easily susceptible to rust or corrosion. The outdoor AC unit or heat pump contains components such as the condenser coils and compressor which are made of materials that stand up to constant moisture, dirt, and extreme weather exposure. The outer cabinet of the air conditioner or heat pump is typically composed of stainless steel that may also be covered in a protective coating to give the unit an extra layer of protection against the elements.

No matter which type of outdoor unit you have, proper airflow is critical to the design of any AC unit or heat pump. The outer cabinet is made to offer protection to inner parts while facilitating adequate airflow through the unit, which is necessary for your air conditioner’s efficiency and the air conditioning process that is required to cool your house. The fins along the exterior of the cabinet not only permit airflow through the unit, but they screen out dirt and prevent the buildup of moisture that will lead to mold growth inside the AC unit. Both dirt and mold growth diminish the air conditioner’s efficiency and cause damage to the outdoor unit, as well as negatively impact your home’s indoor air quality.

What Are AC Covers?

AC covers are available online and at local home improvement stores. An air conditioner cover is typically made of water-resistant material such as plastic, canvas, or a screen mesh for a breathable cover. They can be installed over air conditioner or heat pump units installed in very small spaces or to cover a unit that sits out in the open. An air conditioner cover is usually held into place atop and around the unit by buckle straps or similar closures. 

Should You Cover an Outdoor AC Unit over the Winter?

The mere fact that the air conditioner cover exists does lead many homeowners to believe you should cover your air conditioner to protect it over the winter months when it is not in use. The truth is that an AC cover isn’t necessary. You don’t need to cover your air conditioner when it gets cold outside because the AC unit is designed to withstand harsh winter weather conditions as well as withstand exposure to the elements year-round over spring, summer, and fall, too.

An AC cover is entirely optional for any outdoor unit of a home’s air conditioning system. Using AC covers to cover your air conditioner for the winter months can offer some additional protection against falling branches and other tree debris that could damage the unit, but generally, the exterior cabinet is strong enough to block even heavy limbs and other debris from impacting the inner components.

Can Covering Your Air Conditioner Cause More Harm Than Good?

The main concern about covering your air conditioner over the winter is the unintentional damage that can result from covering the outdoor unit, even when using an air conditioner cover that was designed for this type of use.

Problems When You Trap Moisture Inside

An air conditioner cover has the potential to trap moisture inside your air conditioning unit, which will lead to mold growth and quicken the development of rust and corrosion to your air conditioner.

As mentioned above, the outer cabinet of any air conditioner or heat pump unit is designed to allow for proper airflow through the equipment. Not only is airflow access necessary to the performance of air conditioners, but moving air also prevents moisture from accumulating within the unit and reduces the amount of dirt and other debris that fall on the property and collect inside the air conditioner.

Covering your air conditioner with an AC unit cover can cause more harm than good over the cold winter, working against your mission to protect the air conditioning unit. Covers installed to encase the unit trap moisture inside from rain, snow, and other winter precipitation, while also restricting airflow needed to rid the unit of accumulating moisture. When covers are used over long periods, such as over the winter months, you’re likely to have a mold problem within the air conditioner come spring when the cover is removed.

Prolonged exposure to moisture from rain, snow, and ice within the air conditioner can cause the air conditioning unit to sustain rust and corrosion prematurely. Rust and corrosion can impact the condenser coils, compressor, condenser fan, and other important parts within the outdoor AC unit. While these components are built to withstand regular exposure to the elements, when you keep moisture trapped within air conditioners over a long period of time, even the most durable materials will degrade.

Problems After Winter

Once cold weather passes, it’s important to remove covers if you cover your air conditioner for the winter. Leaving covers in place longer will further contribute to any mold problems or moisture damage occurring within the unit, but the bigger concern comes when it’s time to use air conditioners once more. Operating an AC unit with a covering in place can severely damage the system, which may require significant repairs or replacement of heating and cooling equipment.

Any covering installed must absolutely be removed before turning on the system again. This means if you use your heat pump system for heating over the winter, you should never cover the outdoor unit! If you fail to take off the covering and start up the air conditioner, the cover will greatly block airflow through the unit. Operating the air conditioner for any amount of time after you install something that will block air movement severely stresses internal parts and will cause components to sustain damage or fail entirely.

How to Protect an Outdoor Unit over the Winter

Rest assured that your air conditioner can easily withstand the cold temperatures, snow, rain, and other harsh winter weather conditions without any sort of covering installed for the season. If you want to protect this part of your heating and cooling system from damage due to debris, you can install a simple cover made of plywood cut to fit the top of the unit.

A plywood cover for your air conditioner is a better choice than a commercially available air conditioner cover, but still not a must in cold conditions. If you are concerned that limbs could fall and damage your unit during an ice storm, a plywood cover can offer some additional protection as well as give you peace of mind over the winter. Installing a cover that will block only the top of the unit is less likely to cause moisture buildup, as air is still able to flow through the unit on the sides. Mold from accumulating moisture is less of a risk with this type of cover. The cover can also block out dirt and other debris that the wind may blow into the unit, so there is less to clean up come springtime.

Protect Your Air Conditioner with Professional Help

While AC covers are readily available, adding a cover to your AC unit or outdoor heat pump isn’t necessary to protect your home’s heating and cooling systems. This equipment is designed to withstand snow, rain, dirt, debris, and cold temperatures throughout the spring, summer, fall, and winter. If your air conditioner suffers damage over the fall or winter, contact Williams Comfort Air for professional AC unit repairs and talk to our technicians about how you can safely protect your equipment.

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