SONDEX® / Danfoss Microchannel Heat Exchangers
Microchannel heat exchangers (MCHE) are utilized in air cooling, chillers, dry coolers, and refrigeration equipment where reduced refrigerant charge and compact heat transfer surfaces are required. Constructed entirely of aluminum, refrigerant flows through microchannels instead of conventional fin & tube designs. Compared to fin & tube, a 30% reduction in refrigerant charge and a 10% increase in efficiency under identical conditions are reported.
Typical Applications
- RTU and DOAS ventilation units.
- Chillers and dry coolers.
- Data center cooling with free cooling cycle.
- Commercial / residential air conditioning.
- Refrigeration installations.
Free Cooling in Data Centers
At high external temperatures, only the refrigeration cycle operates. During intermediate seasons, the cooling cycle collaborates with free cooling. At low external temperatures, water or glycol mixtures can be cooled by the free cooling cycle, reducing compressor operation.
Technical Selection Criteria
For glycol MCHE, versions with tube widths of 25.4 or 32 mm, thickness of 2.0 mm, varying port numbers, and fin densities of 18–23 FPI are available. Design pressures range from 6 bar to 45 bar per version, while high-performance versions are specified at 10 bar design pressure and 50 bar burst pressure.
Corrosion and Materials
The aluminum construction reduces the risk of galvanic corrosion. For corrosive environments, selection is based on ISO 9223 categories C1 to CX and required protection: SLA, LLA, top coating, e-coating, or double coating.
FAQ
When to Choose MCHE?
When design prioritizes low refrigerant charge, low weight, and compact heat transfer installation.
What is Needed for Sizing?
Refrigerant type, air flow, temperatures, humidity, available pressure drop, corrosion category, and free cooling operating conditions.