HVAC Tube Bundle Maintenance

Tube bundles are an essential part of the HVAC and hydronic system of a commercial facility. They are the heating elements that exchange and transfer energy in the form of heat into the water that is then typically used for either building heat or domestic hot water requirements. Without this critical component, the system wouldn’t work at all—which is why it’s such a big problem if it fails.

It’s important to make sure that your tube bundles are in good working condition if you want to keep the system functioning at optimal levels. If the HVAC tube bundle ruptures or springs a leak, hard water may enter your condensate return system and damage your boiler, or steam could migrate into your hydronic system and create a dangerous environment to the domestic and/or heating systems. Here are a few things to look for if you’re unsure about how to check your tube bundles for damage.

Signs of Deterioration in Your Tube Bundles

It’s a good idea to schedule regular maintenance for your heat exchangers. If you’re not comfortable inspecting the tube bundle yourself, get a professional to help you out. Otherwise, we recommend looking for these signs which indicate that you may need some repairs:

• Corrosion on the tubes: Most tube bundles are made from conductive metals, such as copper. On these metals, corrosion usually appears as a slimy or flaky green/brown tint. Over time, your tubes will likely corrode a small amount as they are exposed to the water/steam moving through the system. A little corrosion is nothing to worry about. However, corrosion weakens the metal and can eventually cause it to break or release tiny particles of oxidized metal into the fluid running through your tube. So, if you see a lot of corrosion, call a professional.

• Air and dirt in the system: No matter how well-crafted a tube bundle is, it will experience wear and tear that may degrade it. These contaminants can be hard to spot because they are behind the opaque surface of the tube. Look for dirt buildup at the base of the tubes where they meet with the tube sheets and baffles. If there is significant dirt buildup there, especially if it is slimy or pitted, call a professional. Leaking tube bundles can cause additional problems for your domestic water and heating system.

• Pinhole leaks: Sometimes, a leak in your system won’t be visible to the naked eye. If you see the hard water showing up in your condensate return to your boiler, you may have a leak. Isolate the suspect heat exchanger from the steam supply and then open the water valve while also opening the condensate wye strainer drain. If the water begins to flow out of the strainer, you know you’ve got a failed tube bundle. This problem can be disastrous if left unattended. Allowing failed tube bundles to leak into your system can be very dangerous, especially if hard water makes it back to your boiler and is left unaddressed for a prolonged period of time.

You don’t have to shoulder the burden of checking your tube bundles for leaks alone. Call the professionals at Cooney Coil & Energy if you need assistance with diagnosing the problem and finding the right parts for repair or replacement tube bundles.