When legacy air conditioning units and chillers begin to lose efficiency or leak, heat exchanger replacement may be a low-cost alternative to full system upgrade. Microchannel heat exchangers (MCHEs) have several advantages over traditional fin-and-tube coils that make them a great option for retrofitting legacy equipment.
Why Choose Microchannel Heat Exchangers?
Microchannel technology enhances refrigerant charge reduction, improves heat transfer efficiency, reduces energy costs, and is more resilient to wear than conventional coils. With their small size, they are easier to install in confined spaces, and their all-aluminum construction is less susceptible to corrosion than copper-aluminum coils. For older Trane, Carrier, or other manufacturer chillers, a Trane replacement coil with microchannel technology may provide the ability to restore performance while decreasing energy bills.
Key Features of Microchannel Replacement Coils
• Increased Efficiency
Microchannel heat exchangers contain larger surface area and optimized airflow, leading to increased heat exchange. This means reduced compressor workload and reduced energy consumption.
Lower Refrigerant Demand
Due to their smaller internal volume, MCHEs use less refrigerant, which is something that is further beneficial as regulations eliminate high-GWP refrigerants. It also decreases potential leak points.
Corrosion Resistance
Aluminum construction is less prone to saltwater, chemicals, and oxidation than standard copper tubes, resulting in the coil having a longer lifespan in harsh conditions.
Lightweight and Space-Conscious Design
Microchannel coils are significantly lighter than standard coils, as they are easier to handle and install. Their space-saving size makes them ideal for retrofitting existing older systems with limited space.
Legacy Chiller Replacement Alternatives
Three major methods to replace a heat exchanger in a current older chiller are:
1. Direct Substitution with OEM Coils
Some operators like to keep the coils from the original manufacturer for compatibility reasons. However, OEM replacements are expensive and lack the efficiency improvement of newer technology.
2. Microchannel Drop-In Substitute
A microchannel coil can often be dropped into a substitute for a current fin-and-tube assembly. Some aftermarket manufacturers offer Trane substitute coil options that fit existing connections and dimensions but deliver more performance.
3. Tailor-Made Microchannel Solutions
Custom-made microchannel heat exchangers can be built to specific requirements for chillers of unique designs. This maximizes airflow and refrigerant flow and provides optimum efficiency gains.
Things to Consider Prior to Replacement
Compatibility
Make sure that the replacement coil is compatible with the original system’s refrigerant type, pressure ratings, and connection points.
Airflow and Pressure Drop
Microchannel coils can have varying airflow patterns compared to conventional coils. Make sure the replacement does not compromise system balance to reduce efficiency or cause overheating.
Installation Requirements
Even though microchannel coils are more manageable, proper brazing and refrigerant handling protocols should be used to avoid leaks or contamination.
Cost vs. Long-Term Savings
While microchannel coils are initially more expensive than some OEM counterparts, their energy efficiency and extended lifespan usually make the added cost worthwhile.
Applications where Microchannel Excels
Microchannel heat exchangers shine in these applications:
- Commercial HVAC systems
- Industrial chillers
- Refrigeration units
- Process cooling systems
For structures with aging Trane chillers, a new coil from Trane that incorporates microchannel technology can significantly improve reliability and performance.
Last Thoughts
Replacing the heat exchanger of an old chiller with a microchannel unit can extend the life of the system by many years, reduce operating costs, and make the system more environmentally friendly. Look at performance specifications, compatibility, and long-term benefits when selecting a replacement to achieve the best fit for your application.
Operators can upgrade older chillers without the expense of replacing a complete system by employing a high-quality microchannel heat exchanger, making cooling systems function properly for years to come.
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