Stopping Corrosion From Impacting HVAC Coils
There are a few important coil components within any modern HVAC system, and ensuring their care is very important for long-term maintenance. These coils allow for the transfer of temperature and a few other important processes within your system, but improper maintenance may lead to a few issues — and one of the most common is corrosion.
If you utilize quality HVAC professionals for all your basic HVAC maintenance and upkeep needs, these sorts of problems are extremely unlikely to occur. Here are some basics on the important coils in your HVAC system, what may cause them to corrode, and what can be done to stop this from happening.
HVAC Coils and Why They Matter
Within the standard HVAC system today, two specific coils are present:
- Condenser coil: Present in your outdoor AC unit, this coil helps to cool the refrigerant gas as it moves through the system. It also helps to remove any moisture that may have built up.
- Evaporator coil: Present inside the home, the evaporator coil pulls heat from indoor spaces, then delivers that hot air to the HVAC unit — at which point it can be absorbed by the refrigerant in the condenser coil.
If either of these coils is not functioning properly, it can lead to a variety of different problems.
One issue that may develop is coil corrosion. This occurs when the metal of the coil begins to deteriorate and rust. Let’s go over why this happens in our next section.
Causes of HVAC Coil Corrosion
Generally speaking, there are two primary reasons why HVAC coils may corrode:
- Exposure to corrosive substances: In some cases, the condenser coil will have undergone prolonged exposure to a corrosive substance. This could be anything from a salty atmosphere to acidic rain. Some of the most common such substances are fluoride and chloride — these are often present in other home systems like water treatment and plumbing, and may cause problems if they leak into the AC unit. Other examples include: sulfuric acid, nitric acid, and chlorine.
- Airborne volatile organic compounds (VOCs): These are chemicals that are released from certain materials (like building insulation, carpets, furniture, and even some paints) when they heat up. Over time, these VOCs can form a layer on the coils that will corrode them. They can also transform into caustic formic and acetic acids when they land on the surface of a coil, which will speed up the corrosion process.
Both of these causes will be more prevalent in certain geographic areas than others. Coastal areas, for example, are more likely to have corrosive air and water due to the high levels of salt in the air. If you live in an area with known coil corrosion issues, it’s important to take extra precautions to prevent this from happening.
Avoiding Coil Corrosion
The single best tool at your disposal for avoiding corrosion within any HVAC coils: Regular maintenance and cleaning. If you have your coils cleaned and inspected by a professional at least once a year, the majority of potential problems can be avoided.
In addition, there are a few things you can do to help protect your coils from corrosion:
- Make sure any corrosive substances that may come into contact with the coil (like salt water or other chemicals) are kept away from the unit.
- Install a coil coating: A good coil coating can help to protect the metal from airborne VOCs and other corrosive agents.
- Monitor your indoor humidity levels: Keeping the humidity levels in your home between 30-50% will help to reduce the likelihood of coil corrosion.
Keep these tips in mind as you care for your HVAC system through the years, especially if you’ve had coil issues in the past.