- The transition from copper to aluminum for HVAC manufacturers.
- Pros and cons of copper versus aluminum for HVAC equipment.
- trying something new or keeping the status quo?
- a video debunking the “aluminum is difficult to repair” myth.
- Plenty of resources and in-depth related links to help you learn
Conductivity of Copper Versus Aluminum Coils | Copper Versus Aluminum Coils - Condensers and Evaporators
Copper Versus Aluminum Coils - Condensers and Evaporators - Some manufacturers are starting to transition from copper coils to aluminum coils for both condensers and evaporator coils for various reasons. Let’s explore aluminum Vs copper HVAC coils.
When making a decision to purchase a new system you need to inform yourself about the pros and cons of purchasing a system with aluminum coils or copper coils. Traditionally, copper was the chief material to use to manufacture evaporator coils and condenser coils. That was because of heat transfer rate, cost, pliability (easy to bend and swage). Additionally, because copper line sets are used to join split systems.
The cost of copper has skyrocketed and that was a game changer. Many manufacturers have started looking at aluminum. Simply because the cost of aluminum is cheaper than copper. Additionally, aluminum has some of the same benefits of the above-mentioned properties that copper has.
Heat Conductivity Facts
Copper has approximately twice the conductivity of heat transfer of aluminum and therefore is more efficient at transferring heat. An air conditioner or heat pump works on the principle of refrigeration. The classic definition of refrigeration is moving heat from a place where it is not wanted to a place where it doesn’t matter. Furthermore, that means it is important to use materials that efficiently move or transfer heat. In this regard, copper wins.
Additionally, another pro for copper is the ease of repairing the copper coils in the field if they become damaged. Aluminum coils, if damaged, are very difficult to repair and often times need to be replaced.
Pros and Cons of Copper Versus Aluminum Coils - Condensers and Evaporators
- Heat transfer
- Repair when damaged
- Galvanic corrosion
- Formicary Corrosion
- Thinner because of cost
- Fins and Coils
- Dirty Sock Syndrome
1Copper has a better heat transfer rate than aluminum
Repair When Damaged
2A copper is easily repaired in the field when damaged. Whereas aluminum, when damaged, typically requires an entire coil change.
3Because copper is used for the line set. Additionally, fins are aluminum, where the copper joins the aluminum, it is subject to galvanic corrosion. Galvanic corrosion happens when two dissimilar metals are joined. Modern technology and advancements in joining dissimilar metals have made this con very minimal for aluminum.
4Copper is subject to formicary corrosion. This is a not a problem as long as the coils are given proper and regular maintenance.
5Modern technology and the price of copper has made manufacturers use thinner and thinner copper. The new refrigerant replacing the old HCFCs operate at higher pressures therefore, the newer copper is more likely to spring a leak because of the thinner copper and the higher operating pressures.
6The traditional perception is that copper is more durable than aluminum. But again that will soon change as the copper gets thinner and thinner because of the rising cost.
7Since copper is very expensive it makes it a target for thieves. A contractor friend of mine just replaced some air conditioner condensers and all the copper the thieves could get their hands on, for a church.
Now its bad enough they hit a church (imagine the implications of that in the afterlife…..LOL) but it is now necessary to secure copper including condensing units to discourage theft. That is an added cost for the end consumer.
Fins and Coils
8Condensing unit with copper coil & aluminum fins? I have read that as much as copper suffers from formicary corrosion aluminum suffers from bacteria and mold issues.
The problem with that argument is that manufacturers have always used aluminum fins over the copper tubing to increase the area for heat absorption and to channel the air more effectively across the coils. Besides that, anyone with mold or bacteria problems need to use a UV Air Cleaner inside their ducts.
Dirty Sock Syndrome
9For those who have all aluminum coils used for air handler coils, I had experienced from my customers and heard anecdotal accounts of people complaining of malodorous smells including metallic smells.
This problem is not isolated to heat pumps (dirty sock syndrome) but also to air conditioners. Could it be that the copper repels bacteria and mold while aluminum does not?
Copper Versus Aluminum Coils - Condensers and Evaporators | Traditional Coils
The traditional coils, copper tubing with aluminum fins have been used for years and years in condensers and for evaporator coils. These coils are tried and true so anything new on the market is subject to some apprehension.
Trane has been using aluminum for years and years and they offer a good warranty for their product so aluminum can’t be that bad for use in HVAC equipment.
Additionally, refrigerator and freezer manufacturers have used aluminum coils for many years for the coils in their products. What is your opinion based on the facts? Leave your opinion in the comments below.
As for me, I give my vote to tradition and stick with copper.
Here is a video of a repair to aluminum coils in case of a puncture or leak in the coils. Not sure how this stuff would work for joining two dissimilar metals together such as copper and aluminum but this is a plus for aluminum coils.