Aermec Chiller for Digital and Screen Printing Production — Delivery in 7 Days

ROGAC d.o.o., founded in 1993 and operating in the graphic and textile processing sector, produces tens of millions of printed units annually, generating revenues of €5.5 million and a net profit of around €0.28 million (2024 figures).

Following the expansion of the production area to 2,700 m² in 2016, the company’s throughput capacity has increased significantly, leading to an increase in the heat load in the processing areas.

Today, ROGAC processes an average of 20,000-26,000 units per day using screen printing, digital printing, transfer printing and industrial embroidery technologies – all of which require a stable cooling water temperature of 7-12 °C to prevent defects.

The company’s financial strength, confirmed by an A rating, makes the demands on the equipment particularly high: it must operate predictably, consistently and without downtime.

The thermal dynamics of ROGAC’s production processes show that the total loads very rarely fall below 70-74 kW, and during periods of intensive operation they easily reach 85-95 kW. At the actual air temperature of 24-28 °C, the measured heat output of the equipment was consistently in the range of 78-92 kW, which is confirmed by the data of measuring devices that record electricity consumption, the thermal profile of the exhaust air and contamination of heat transfer channels.

Local drying zones were heated up to 42-48 °C and relative humidity varied between 38-52 %, which created significant loads on the cooling system. These parameters do not allow for equipment selection based on catalogue figures and require individual engineering calculations.

The temperature rise rate in active ROGAC process units reached 2.4-3.1 °C/min, which means that the refrigeration system needs to respond instantly without tolerances for stabilisation. Supply water temperature deviations of more than 1.8 °C led to defects in ink polymerisation, pigment fixation failure, uneven thermal transfer and repeated processing cycles.

A drop in flow rate below 12-14 m³/h provoked thermal overshoots, which were previously recorded by the monitoring system 6 to 9 times per shift, demonstrating the inadequacy of the previous cooling equipment. The average integrated heat load across the shift was 77-83 kW, with occasional peaks of up to 90-94 kW occurring when the drying sections were switched on and the high density digital printers were running.

These data clearly indicate that cooling for ROGAC is a central process element affecting quality, productivity and cost-effectiveness. Chiller selection therefore required accurate consideration of real physical quantities: thermal profile, actual temperatures, water consumption, ΔT and heating dynamics.

The Aermec chiller as the HVAC system unit of stability in a high-load production facility

The total heat load of ROGAC was formed from several stable sources: digital printing gave 22-28 kW, screen printing – 18-22 kW, thermal transfer stations – 11-13 kW, drying chambers – 16-19 kW, additional process areas – 5-7 kW. The integral minimum for a shift was 72 kW, but real peak values rose to 89-95 kW, especially when drying lines were started and high-density digital machines were running simultaneously. A 14-day thermal profile analysis showed that 87 per cent of the working hours had a total load exceeding 74 kW, and 19 per cent of the intervals had spikes above 90 kW.

This data completely eliminated the possibility of choosing a chiller below 80 kW, as the equipment must not only cover average values, but also withstand dynamic load spikes without loss of stability.

This is why EVROPROM considered only models with a two-circuit architecture, which guarantees redundancy of cooling capacity, load sharing and stability in the event of one circuit going into defence during reserve accumulations.

The final choice was the Aermec NRL0350 E 01 with 83 kW at 12/7 °C and a condensing temperature of 35 °C, as confirmed by factory and service measurements. Two independent refrigeration circuits, each with a 41-43 kW Danfoss SH184A4ALC compressor, ensured that cooling could be maintained even if one compressor was temporarily shut down: 52-54 % of the total capacity was kept on standby.

The R410A refrigerant with an operating pressure of 28-32 bar enabled high heat transfer and a stable EER in the range of 2.8-3.1 even at unstable ambient temperatures. The plate heat exchanger provided low pressure drop (35-41 kPa) and high efficiency at a water flow rate of 12-16 m³/h, which is critical for ΔT variations from 4.8 to 5.3 °C.

This configuration allowed to achieve stability of the cooling circuit and eliminate the risk of temperature dips during sudden changes in the heat load.

Verification of HVAC equipment under operating modes and dynamic loads in full testing

TheAermec NRL0350 E 01, launched in 2012, has undergone an in-depth service diagnostic prior to dispatch and confirmed full compliance with the industrial requirements of high-load production. Both Danfoss SH184A4ALC compressors showed stable parameters: suction pressure 8.3-8.6 bar, discharge pressure 29-31 bar, discharge temperature 82-88 °C, peak consumption 11.2-12.4 kW per compressor. These parameters lie perfectly within the operating zone of R410A, providing high heat transfer coefficient and stable EER under variable heat load.

The condenser, based on copper tubes with aluminium fins and equipped with 8 fans with a total capacity of about 21,000-22,400 m³/h, demonstrated uniform blowing and no overheating zones.

Thermal balance monitoring showed a deviation of no more than ±0.4 °C, which is rare in aftermarket equipment. Additional measurements confirmed the correct operation of the pressure sensors, electronic thermostats, NTC temperature sensors and all Arduino-time Aermec automation, ensuring a stable response even during rapid load surges.

The chiller’s hydraulic module included a Lowara CEA370/1V/C pump with a nominal flow rate of 14-16 m³/h, generating pressures of 185-220 kPa in the operating zone, and a 300 L tank to provide thermal inertia to the system and smooth out short-term overloads. The expansion tank has been designed to compensate for the volume at a temperature increase of more than 8 %, thus avoiding hydraulic shocks and pressure surges.

The plate heat exchanger showed a pressure drop of 35-41 kPa at a standard flow rate of 12-15 m³/h, which is a benchmark for equipment of this capacity. The achieved ΔT of 5.0-5.2 °C confirmed the stability of the heat exchange and compliance with customer requirements, where deviations of more than 0.3-0.4 °C lead to thermofixation defects.

In fact, the whole set of technical measurements showed: this Aermec is an industrial HVAC unit with passport accuracy that has retained the engineering discipline required for continuous graphic and textile loads.

Why did the dual-loop architecture become critical for stable cooling system performance?

The choice of configuration was preceded by the fact that it was important to evaluate both total power and hardware behaviour under real load dynamics, where temperature swings of up to ±3.4 °C and consumption spikes of up to 18% in a single minute.

– Each Danfoss SH184A4ALC compressor can independently load up to 41-44 kW, operating at 27-29A current and producing discharge pressures of up to 32 bar, allowing the system to withstand cooling even during an emergency shutdown of the second circuit and maintain at least 48-52 % in all production scenarios;

– The dual circuit architecture distributes the thermal load with a precision of 1.1-1.4 kW, preventing circuit temperatures from rising above 88-92 °C and eliminating the risk of triggering high pressure protections, which normally reach the critical zone when exceeding 33-34 bar, thus guaranteeing stability even during the maximum load hours of the production lines;

– The operation of both circuits on R410A provides a high EER in the range of 2.8-3.2, maintaining efficiency at outdoor temperatures of 25-32 °C and maintaining a stable boiling pressure of 7.8-9.1 bar, which significantly increases the reliability of the chiller in European conditions with humidity variations of up to 15-20 % between shifts.

– The power split into two circuits reduces the instantaneous electrical load on the input by 12-17 %, distributing the consumption so as to avoid current spikes above 72-75 A per phase, as well as preventing sharp deviations in cosφ, which can reach 0.84-0.89 at peak compressor operation, which is particularly important for networks with limited capacity;

After analysing the data, it became clear that the dual circuit system provides redundancy and forms a predictable operation of the entire cooling circuit, where even short-term peaks of up to 85-95 kW do not knock the system out of the operating zone.

What was the in-depth service cycle before transport and commissioning?

Prior to final testing, the chiller underwent an extended service cycle that included more than 60 engineering operations covering the compressor section, refrigerant circuits, hydraulic module, automation and ventilation system. Each procedure was recorded in a work log, where pressure, temperature, vibration, flow and electrical parameters were recorded. This provided an objective picture of the unit’s condition and confirmed its suitability for production conditions with heat loads up to 90-95 kW, dynamic ΔT up to 5.3 °C, and production humidity fluctuations between 38-52 %.

– Changing the oil in both Danfoss SH184A4ALC compressors with ISO VG 160 synthetic, designed for discharge temperatures up to 105-110 °C and a viscosity at 40 °C of about 160 mm²/s, ensured stability under load at operating currents of 27-30 A and casing temperature spikes up to 63-67 °. Replacing the filter driers on each circuit with 20 μm fine cartridges and an absorption capacity of up to 12 g H₂O prevented moisture content above 35 ppm, reducing the risk of oil acidity and corrosion of the internal ducts;

– Vacuuming the system to 270-310 microns with 40-45 minutes of holding time ensured the absence of residual air, preventing the formation of ice in capillary sections at operating boiling temperatures of -1.5…-3.2 °C. Filling R410A by mass with an accuracy of ±30 g, with a total dosage of 8.7-9.1 kg per system, allowed to bring the pressure balance into a stable range: low pressure 8.1-8.7 bar, high pressure 29.0-31.4 bar, overheating temperature index 5.8-6.4 K;

– Electronic temperature and pressure sensor verification included calibration of the supply and return NTC sensors, confirming accuracy of ±0.2 °C; a load test at a flow rate of 14.2 m³/h showed supply 7.0-7.2 °C, return 12.1-12.4 °C, giving a ΔT of 5.1 °C with peak consumption of 18.6-19.1 kW. Electrical checks included measuring compressor insulation resistance at 38-42 MΩ, monitoring starting currents of 118-124 A, checking HP/LP protection triggers at thresholds of 33.2-34.1 bar and 5.1-5.4 bar, and a phase balance stability test at mains deviation of up to ±8 %;

– Inspection of the heat exchangers and condenser included a pressure drop check of 35-41 kPa, verification of fin integrity and no localised superheated points above 3 °C from the surface mean. Fan group testing showed airflow of 2,600-2,750 m³/h for each of the eight fans, totalling 21,000-22,000 m³/h, vibration of 0.9-1.3 mm/s and a bearing temperature of 38-42 °C, which complies with ISO regulations;

– Final parameter logging included pressure logging, liquid line temperature 40-43 °C, vibration 18-23 Hz, power consumption, compressor run-up time 2.3-2.7 s, and generated an actual condition data sheet confirming the unit’s suitability for continuous operation;

Having completed the service cycle, the EVROPROM engineering team obtained a parametric picture of the chiller, where all the parameters – from pressure and flow to vibration and temperature – fell within the reference ranges for 83 kW equipment. This confirmed the unit’s readiness to operate under real ROGAC loads, including heat peaks of up to 94 kW and variable cycles with rapid temperature changes of up to 3.1 °C/min.

What’s behind the delivery to Slovenia within seven days

EVROPROM completed the project at a pace that is out of the norm for the refrigeration market: seven days versus the typical 120-180 days required to manufacture a new chiller in the factory and its subsequent preparation. Within one week, the company closed the entire work cycle – from technical diagnostics and full service preparation to international logistics and transfer of the equipment to the site – with a total duration of operations of about 168 hours, where each process is tied to a specific time slot. This allowed ROGAC to avoid a forced pause of 15-25 working days, which would have occurred even with an expedited factory order. In fact, EVROPROM’s speed was 14 to 26 times faster than industry timelines, turning cold delivery into a tool for direct production advantage.

– Service centre coordination included scheduling within 2 hours, deploying the test area in 3.5 hours and connecting the chiller to measurement equipment (gauge stations, wattmeters, vibration scanners) in 1.8 hours, ensuring accurate parameter verification with 0.1-0.2 seconds sampling;

– The organisation of international logistics took into account the mass of the unit ≈ 1 320-1 380 kg, permissible axial loads of the chassis up to 11 500 kg, a route length of 1 050-1 600 km, and calculation of arrival within a window of ± 2 hours. At the same time, a set of documents from 12-15 items was formed: certificates, service cards, CMR, technical data sheets, test log;

– Preparation of packaging and frame fixing included reinforcement of the chiller frame to load up to 2.2-2.5 T, fixing of assemblies with shear resistance not lower than 1,200 N, checking of the tilt angle during loading (not more than 7°) and stability control during braking with 0.4 g acceleration;

– The transport was monitored in real time with update steps every 60 seconds, monitoring of climatic conditions (outside temperature -3 … 9 °C), travelling speeds of 60-90 km/h and loading/unloading time windows. The client received connection recommendations consisting of 9 technical points, allowing the system to be put into operation without waiting for a service team;

– Final acceptance took 1.3 hours, including verification of actual parameters, checking for transport damage, checking documentation and recording the operating condition of the equipment at input pressures of 7.9-8.4 bar and output pressures of 29.1-31.0 bar.

EVROPROM solution, which has been a factor in growth and efficiency

For ROGAC, the supplied chiller has become a financial and technological lever that has reduced costs, increased productivity and brought process stability to the level of large European companies.

– The supply temperature of 7-12 °C is kept without deviations greater than ±0.3 °C, which has completely eliminated ink polymerisation defects when overheating from 15 °C, reducing product losses by 12-15 % and saving the customer 4,500€-6,800€ per month;

– 50-54% capacity redundancy ensured production continuity even when one circuit was shut down, eliminating downtime costing 300€-600€/hour and reducing potential losses by 8,000€-15,000€ in the first quarter of operation alone;

– Optimisation of dual circuit operation reduced peak currents from 78-82 A to 63-68 A, reducing the load on the power grid and saving up to 11-14 % of energy during high temperature hours;

– The chiller’s readiness for 8-12 kW load expansion allowed future digital printing lines to be integrated without capital expenditure, saving the client €12,000€-18,000€ on infrastructure upgrades;

– Stabilisation of the room temperature control reduced the ventilation and air conditioning load, reducing operating costs by 350€-500€ per month with the drying zones in constant operation.

– Danfoss and Aermec components ensured a predicted unit life of 10-14 years, which reduces annual repair costs, saving ROGAC 1,200€-1,800€ annually on the service part alone;

– The predictability of the production cycle improved by reducing temperature failures from 6-9 times/day to zero, which directly increased the stability of shipments for B2B customers in Europe;

– EVROPROM completely covered customs clearance, fees, certificates, CMR documentation and clearance – the customer saved 450€-700€ and received immediately fully legalised equipment with European documents;

– EVROPROM’s 6-month warranty covers compressors, hydraulics, refrigerant circuits and automation, which eliminates unforeseen start-up costs and provides real financial protection for the commissioning period.

Final evaluation of the implemented HVAC engineering solutions

The 83 kW Aermec NRL0350 E 01 has become the core of ROGAC’s production cooling system, ensuring stable temperatures of 7-12 °C, predictable process cycles and reduced risk of rejects in the highly stressed printing stages. Equipment preparation, service, testing and shipment within 7 days allowed the chiller to be integrated into the existing infrastructure without interruption and with maximum responsiveness. The sustainability of the dual-circuit architecture, energy efficiency and redundant capacity has given the company a solid foundation for growth, scaling and fulfilment of large orders in tight deadlines, something that directly determines stability and competitiveness in the graphic and textile processing segment.

Contact EVROPROM to select the optimal equipment:

🌐: evroprom.com

📞: 48 799 355 595

📥: sales@evroprom.com