Microchannel Fluid Coils Deliver 500 kW Duty with 40 % Less Glycol

District-energy networks running 50 % glycol at 8 °C now use microchannel fluid coils to transfer 500 kW of heating or cooling while cutting pump flow 40 %.

Kaltra’s design feeds water-glycol mixtures through flat aluminum multi-port tubes that contain up to ninety parallel channels 0.7 mm wide. The geometry pushes internal heat-transfer coefficients above 5 kW m⁻² K⁻¹ while keeping water-side pressure loss below 25 kPa, so a 1 MW load needs only 32 L s⁻¹ instead of 55 L s⁻¹, trimming pump power 35 %.

Each coil is vacuum-brazed at 600 °C under nitrogen, fusing tube and fin into a single block rated 30 bar and 200 °C. The resulting microchannel fluid coil weighs 30 % less than a copper-aluminum bundle—220 kg versus 420 kg—eliminating the need for extra roof beams when retrofitting existing air-handlers. All-aluminum construction removes galvanic cells, passing 650 h neutral salt-spray without pitting, so coastal substations gain 20-year corrosion protection without epoxy edge coats.

Single-Pass Aluminum Core Survives 650 h Salt-Spray Without Coating

Air-side louvered fins are spaced 18–22 FPI and can be factory-coated with 12 µm cathodic epoxy for sites where chloride exceeds 1 mg m⁻³, extending salt-spray life to 2 000 h while adding only 3 Pa extra pressure drop.

Kaltra sizes every unit through an AI portal trained on 50 000 laboratory points. Enter fluid inlet/outlet temperatures, flow rate, air flow and footprint; the code returns an optimised microchannel fluid coil with validated capacity, pressure drop and live price in sixty seconds. Export files plug directly into Revit, SAP and ERP systems, so structural, energy and procurement models stay synchronised from quotation to commissioning.

Lead time is ten working days; emergency lots ship in 72 hours. Coils leave Graz pressure-tested to 52 bar, dried to −40 °C dew point and plugged with UV-resistant caps. By reducing flow rate, pump energy and roof load in one step, microchannel fluid coils lower district-energy operating costs 20 % and pay back within two heating seasons.