MICROCHANNEL TECHNOLOGY

Microchannel coils

Brazed aluminium microchannel heat exchangers for condenser, evaporator, heat pump, and water coil applications

OVERVIEW

Microchannel heat exchangers suitable for every HVAC application

We offer innovative, next-generation aluminium microchannel heat exchanging products that provide higher heat transfer performance, excellent flexibility, and smaller size: features and capabilities not found in traditional fin/tube heat exchangers.

 

Microchannel technology offers improved performance by increasing air-side heat transfer between the fins and the ambient air, heat conduction between the fins and tubes and refrigerant-side heat transfer between the tubes and the refrigerant, resulting in 20 to 40 percent higher overall performance.

Significant improvements over traditional fin/tube design

HIGHER EFFICIENCY AND PERFORMANCE
  • 20% to 40% greater overall heat transfer performance

  • Drastic reduction in airside pressure drops

SMALLER SIZE AND LESS WEIGHT
  • 10% to 30% smaller coil face upon design conditions

  • Thin profile takes up less space

  • Up to 60% less weight

PROVEN RELIABILITY
  • Time-tested manufacturing processes and materials

  • Higher corrosion resistance

  • Engineered with long-life aluminium alloys

  • Robust construction

REDUCED COSTS
  • Less refrigerant charge

  • Optimized material costs

Technology highlights

TUBES AND FINS

The coil design incorporates vertical tubes and ensures predictable performance. Tube wall thickness is 40% above convenient designs to assure long life operation. A state-of-the-art louvered fin design provides low airside pressure drop and high heat transfer, as well as high water condensate shedding due to using capillary forces and gravity to pull condensate off the coil.

COIL CONNECTIONS

Microchannel coils are available with different types of connections and custom orientations. The special inserts prevent the contact of aluminium and dissimilar metals to avoid galvanic corrosion.

COIL FRAME

The coil itself is a robust frame that provides airtight flush mounting, thereby eliminating unnecessary components and air bypass.

DX DISTRIBUTOR FOR EVAPORATOR AND HEAT PUMP COILS

Built-in DX distributor is designed to evenly spread the incoming refrigerant across the width of the coil. This provides assured coil performance and efficient part load operation. Unlike other coil designs, the lower coil header with integrated distributor eliminates the need for an external distributor and complex piping.

MINI-RECEIVER FOR CONDENSING COILS

The lower header of condenser coils serves as a mini-receiver which accumulates and holds the liquid refrigerant, helps to reduce critical refrigerant change issues and provide easy system charging. The lower header has an internal outlet baffle to allow only liquid refrigerant to leave the heat exchanger and to hold back any refrigerant gas.

MICROCHANNEL CONDENSERS

Condensing coil applications

All-aluminium vertical-flow microchannel coils for condenser applications with ultra-low pressure manifolds are easily configured to exacting performance, up to over 100kW/section applications.

Any coil can be configured in small dimensional increments in height and width, up to as large as 4800x2000mm.

Design working pressure 32 bar and 45 bar models available for the full range of refrigerants, including low-GWP and natural refrigerants.

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LIGHTSTREAM FREECOOL

High-efficient free cooling chillers with inverter compressors and adopted microchannel technology for condensing and free cooling coils. Available in capacity range from 600kW to 1200kW with R1234ze and R134a refrigerants

MICROCHANNEL EVAPORATORS

Coils for evaporator and heat pump applications

Direct expansion evaporator coils are based on innovations in refrigerant flow distribution, combined with a water-shedding coil design.

 

Up to 100kW/section models are available up to 2400mm wide and 2400mm tall with design working pressure at 20 bar, 32 bar, and 45 bar.

 

Available for the whole host of HFC, HFO, and for natural refrigerants.

UNIFORM REFRIGERANT DISTRIBUTION
HIGH-PERFORMANCE TUBES AND FINS
FREE CONDENSATE WATER SHEDDING

Microchannel evaporator

Built-in refrigerant distributor: how it works

Liquid/gas refrigerant mixture from the expansion valve enters the lower header connection and into an internally snug DX distributor tube with orifices to spread out the refrigerant over a width of the coil.

 

The distributor orifices feed a narrow gap that directs the refrigerant to a final stage of atomization injection, where it is injected in close proximity to the coil tubes.

 

This sheer thin wall of refrigerant allows each tube to be equally fed for evaporation and heat transfer in the microchannel tube.

 

Good velocity in the tubes and distributor dynamics assures no oil trapping, good performance, and turn-down to 20% load, if needed.

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LAMBDA DX/DXU

Leading edge direct expansion precision cooling system which offers the latest innovations, including microchannel evaporators, resulting in significant performance and efficiency improvements

MICROCHANNEL WATER COILS

Coils for single-phase applications

For applications up to 225l/min, water, glycols and special fluids, fluid coils can be configured for high efficient chilled water coils, as well as general purpose cooling or heating coils.

 

Water coils are available up to 4800mm wide and 2000mm tall rated for 20 bar.

Related products

PEOPLE WHO VIEWED THIS ALSO VIEWED:

LIGHTSTREAM FREECOOL

High-efficient free cooling chillers with inverter compressors and adopted microchannel technology for condensing and free cooling coils. Available in capacity range from 600kW to 1200kW with R1234ze and R134a refrigerants

Protective coatings: epoxy electrocoat

While all-aluminum microchannel coils are not subject to the same galvanic corrosion issues as traditional fin/tube coils, there are situations or installations that may require the highest level of protection. It is recommended to use epoxy electrocoating for petrochemical installations, adiabatic systems, as well as for installations in highly polluted areas.

Epoxy electrocoating offers the ultimate corrosion and chemical resistance, provide excellent salt spray and humidity resistance and exhibit outstanding performance over aluminium.

Robustness and corrosion resistance

The corrosion potential of the all-aluminium microchannel coils is significantly lower than in bi-metal coils as there are no dissimilar metals to initiate galvanic corrosion. This makes microchannel coils an inherently better solution for seashore installations, installations in polluted areas, or any application where corrosion may be a concern.

 

Microchannel coils require only one braze operation in the controlled environment, significantly reducing the likelihood for leaks when compared to manually brazed heat exchangers.

 

The advanced technology, accurate material selection and use of modern braze furnaces guarantees the highest quality of Alcoil products, which is confirmed by both SWAAT tests and field experience.

Seawater acetic acid test (SWAAT), ASTM G-85 Annex A3

A test specimen is placed in a chamber and exposed to a changing atmosphere that comprises the repeating cycle:

  • 30 minutes exposure to a continuous indirect spray of acidified (pH 2.8 to 3.0) synthetic seawater solution, which falls-out on to the specimens at a rate of 1.0 to 2.0 ml/80cm²/hour

  • 90 minutes exposure to a high humidity (98%) air​

 

The entire test is performed at a constant chamber temperature of 49°C

Product selection software

MCHE selection software includes condenser, evaporator, heat pump, and water coils making it a complete selection and calculation tool for refrigeration professionals. The software offers:

  • Microchannel heat exchanger calculation tool and selection based on user-defined parameters

  • Technical data sheets

  • Drawings

  • Ratings

  • Export functions

  • Automatic updates

 

The software provides selections for microchannel heat exchangers which enables the user to select the best-suited product based on several deciding parameters such as heat exchanger application, cooling capacity, refrigerant, evaporation and condensation temperature, airflow and air temperature and other critical variables in refrigeration systems.

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Kaltra Innovativtechnik GmbH


Max-Reger-Str. 44
90571 Schwaig
Germany


Email: info@kaltra.de
+49(0)911 715 32021

VAT: DE300943964

Kaltra is a customer-focused developer and supplier of reliable, energy efficient thermal management equipment and solutions.

 

From the professionalism of our research and development engineers to the wide experience of our service team, we are dedicated to delivering you the best service possible.

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