Is Coil Corrosion Impacting Your HVAC System?

Coil corrosion is responsible for around 40 percent of all equipment failures in commercial facilities, making it one of the most expensive problems associated with your HVAC equipment. Coil corrosion starts small, but if left unchecked can quickly escalate, leading to coil replacement, or even requiring the entire system to be replaced.

Coil corrosion isn’t something that only happens with old equipment. In certain situations, you can find corrosion occurring as early as a few weeks after installation. It comes in two forms: pitting or formicary.

Pitting corrosion is caused by exposure to fluoride within the water supply, or through chloride found in a variety of products such as detergents and cleaners.  As ions from fluoride or chloride are transported into the system and make their way across the coils and condensate, the ions attack and begin pitting the metal. Over time pinholes are created, allowing refrigerant to leak.

Formicary corrosion is caused through access to acids present in a wide variety of products including cleaning solvents, adhesives, paints, plywood, and so on. Formicary corrosion is often referred to as ants nest corrosion because it tunnels within the tubing in a similar fashion to the way ants create their nests. Over time, the pinholes form in the coils, which lead to refrigerant leaks.  

While coil manufacturing companies are aware of the problem and are applying coatings prior to sale, there are a variety of companies that make aftermarket coatings that you can use to reduce corrosion on older systems already in place.

When coils are damaged, it has a variety of consequences on your overall HVAC system.

It starts with requiring your system to run harder to produce the same results. If the coils aren’t producing the required heat source, the compressor will work harder to create the desired results. This increases power usage, lowers the cooling capacity, and causes more stress on all parts of the system. More stress brings on more maintenance. And if the system isn’t producing the right air temperatures, it’s also creating a less than comfortable environment throughout your facility.

Whether coils are coated or not, the best way to combat corrosion and stop it before it occurs is through continuous maintenance. Cleaning coils at least twice per year will clear away any mineral deposits and keep them safe from accumulating corrosive materials. The earlier you catch it, the easier it is to stop it before it impacts your efficiency, and begins degrading your system.

How are you combating coil corrosion?

Troubleshooting The Constantly Running AC Unit

When the temperatures climb well into the 90s and beyond here in the Pacific Northwest, we know we’re in for a long, hot summer. When they dip back down into the 80s and 70s, even for a short while, it can be a welcome relief. That is until you walk into your office and find the AC system running full blast day and night.

When your air conditioner runs without shutting off, or it cycles on and off continuously, there are several areas of concern. If the AC unit is running 24/7, it’s using way too much electricity and elevating your electric bill. It’s also causing undo stress on the unit itself, which will shorten its life overall.

But above all that, it’s cold. And it can be very difficult working eight hours a day in an environment that leaves you needing gloves to survive.

While there are many things that can be wrong with your AC unit, these are the most likely problems.

Dirty Evaporator Coil

When was the last time the evaporator coil was cleaned and conditioned? Dirt and debris can easily get into the AC unit and cover the coil, impeding the cooling process and making it more difficult to maintain the correct temperature. This can happen even if it was cleaned a few months ago, especially if it’s been working overtime during this recent heat wave. A regular maintenance check will allow a technician to clean and maintain an evaporator coil and keep it running efficiently no matter what the temperature is outside.

Frozen Evaporator Coil

If your unit is blowing warm air from the supply vents, it can be an indication that the evaporator coil has frozen. In order to avoid damage to your AC unit, turn off the system and call in a technician right away.

Clogged Air Filter

Air filters are designed to filter and allow a clean flow of air into the AC unit. Over time, this filter will collect dirt and debris, which restricts the amount of air allowed into the system. Without enough air flowing over the coils, the system can cool the air to the proper level, and keeps running all the time.

Low Refrigerant Charge

If the AC unit doesn’t have enough refrigerant in the system, it can’t cool the space. This often occurs when there is a leak in the system. When this happens, the unit will keep running trying to meet demand, causing the system to work harder than necessary. The first line of action is to find the leak and repair it before adding more refrigerant.

Faulty Thermostat

If your thermostat isn’t working correctly, it won’t know when to turn off the unit as it reaches the proper temperature. Check to see if your thermostat matches the actual temperature in your room or building. If it’s below, there’s a good chance your thermostat needs replacing.

Blower And Fan Problems

If the blower motor isn’t producing enough air for your system, or the fan isn’t running at a proper speed to push the air into the system, it can cause the system to run too much. It may be something as simple as cleaning grimy fan blades, or adjusting the speed of the fan.

Improperly Sized Unit

Have you recently renovated your space? Have you changed wall locations and room sizes without upgrading your AC unit to fit the new space? A HVAC professional can analyze your current space to determine the proper load requirements, and make recommendations for how to improve the efficiency of your system.

Many of these issues can be prevented with regular maintenance of your HVAC system. When was the last time your equipment was serviced by a professional technician? 

Understanding Air Flow For A More Energy Efficient Building

Want to strike a balance between having your building reach its optimal energy efficiency and creating a climate that’s comfortable for every person in it? It all starts with understanding air flow.

As air moves and flows, it tries to create a balance between the high and low air pressure areas. If there is a gap and a pressure difference, it will move through that path whether we want it to or not.

To control the air flow, we put up barriers – materials – in order to control or block the air from moving through it. The more we choose to control the air flow, the tighter the blockage must be. Even the smallest of gaps can allow leakage, which will continue to build over time.

If the amount of air removed from an area does not equal the amount of air supplied to that space, then a pressure imbalance occurs.

In all climates, a balanced air pressure is ideal, yet is difficult to maintain. In warm climates, a slight positive pressure is preferred, while in cold climates, a slight negative pressure can help prevent hidden moisture problems building up in remote areas of the building.

A negative air pressure happens when more air is removed than is added. Leaky ducts can create negative pressure by allowing air to flow where its not intended, and allows it to accumulate behind walls, under floors, or in crawl spaces. In summer, the results show as hot, humid air infiltration. In winter, it means cold drafts. If the negative air pressure becomes large enough, it can lead to dangerous backdrafting around flues of combustion appliances.

A positive air pressure happens when more air is brought in than is removed from the space. It can be controlled with a fresh air intake.

While a building rarely achieves a balanced air pressure throughout the spaces, likewise it rarely is balanced in such a way that a negative or positive charge remains dominate from floor to floor, one side to the other. Instead, you’ll usually find pockets of air impacting the building in different ways.

An example would be closing off office space in which there is a register delivering air, but has no return flow in place. This would allow a positive air pressure to continue building in place.

This is also how indoor air quality is impacted. That same space that continually builds up a positive air flow can also allow higher levels of pollutants to accumulate as well. Intake flows can bring in outside pollutants – pesticides, gases, chemicals, carbon monoxide – especially in industrial locations. It can also allow other types of indoor air pollutants to form and grow – mold spores, dust mites, bacteria, viruses – and keep them in concentrated areas of the building. Over time, these substances can leak into other parts of the building, and begin circulating, reducing the air quality overall.

Not sure how the air flow in your building is impacting your energy efficiency? The best place to start is with an energy audit. One of our HVAC technicians can easily share with you where even the smallest of corrections can make the biggest impacts over time.