What it Means to Re-core a Heat Exchanger

We get a lot of questions about what it means to re-core a heat exchanger. It’s a simple process that provides you with a like new unit while saving you money. Let’s look at the difference between a new unit and a re-core.

The main reason to have a heat exchanger replaced or re-cored is because it is failing in some way. Either it leaks or has been damaged leaving the unit unable to effectively cool. Before we explain what’s different about re-coring a unit, let’s look at how a heat exchanger can fail.

Heat Exchanger Construction and Failure

The first thing to understand about a heat exchanger is how it is built. There are two main parts: the core and the tanks. The core is where all the heat exchange takes place and is built using alternating rows of tubes and fins. These are held together by headers which are attached at the ends of the tubes and either brazed or soldered to the tubes. (As a note, some heavy duty heat exchangers do not use headers, such as with our ultimate duty C-Bar design.) Once the core is assembled, the tanks are attached to the core. This design has numerous failure points due to the number of joints. There are joints around each tube where they connect to the header, as well as the joints where the tanks are connected to the header. These joints are usually the weakest spot of any heat exchanger and will begin to leak as they fail.

In addition to the design, the materials used to build the heat exchanger can play a factor in how a heat exchanger fails. Aluminum heat exchangers that transfer heat from a liquid to air can suffer from corrosion if not properly maintained. This is especially true in radiators when the coolant is not regularly replaced which results in a break down of the protective additives. This creates pin hole leaks in the tubes that are difficult to identify. Copper-brass style radiators suffer from a phenomenon called “solder bloom” where deposits build up on the solder used around the tube/header joints. This build up can block tubes and raise the pressure throughout the entire radiator. Not only will the unit provide less cooling, but since copper is much weaker than aluminum, tubes may be blown out to the point where they rupture causing a catastrophic failure of the unit.

While leaks due to joint failure and corrosion are the most common reasons for a heat exchanger failing, sometimes the unit just gets damaged. What would happen to your vehicle’s radiator if someone ran the fork of a forklift through it? Obviously the radiator would be ruined. In all of these situations you have the choice of replacing or re-coring your existing unit, so let’s look at the difference.

Re-Core a Heat Exchanger or Replace It

Re-coring is the process of taking the existing unit, removing the tanks, and attaching them to a new core. What this does is eliminate all the failure points due to weakened joints, corrosion, or damage to the core. This is typically done with all aluminum or copper-brass units. Heat exchangers that use plastic tanks need to be replaced due to the wear and tear that the tanks have experienced. The only time a unit cannot be re-cored is if the tanks are significantly damaged. This can be either physical damage (cracked or warped) or due to corrosion inside the tanks. In these cases, the only option is to purchase a new unit.

You may be asking, “If I’m just getting the same old tanks back, then what’s the point of doing a re-core?” The primary reason is to save money. By reusing the existing tanks, we can save you money over buying a brand new unit. Since the core is replaced, virtually all the wear and tear that the old unit had experienced is eliminated. This is also a much more effective option than trying to repair a heat exchanger (especially when it is made from aluminum). “Repairing” a unit simply patches a hole for a period of time, but since all the wear and tear that has already occurred is still there, it will eventually fail again.

The bottom line is, if you want to effectively eliminate all the trouble spots in an existing heat exchanger while saving money, then having it re-cored is the way to go. When the unit’s tanks are in bad shape and cannot be reused, then a brand new unit is your only option. If you think your heat exchanger may need to be re-cored or replaced, then give us a call and our friendly staff will be able to assist you.

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