Cooling for edge, 5G, and critical infrastructure: From wall-mounted units to turn-key container data centers

STULZ is a leading German manufacturer of precision cooling systems for data centers, telecom infrastructure, and mission-critical facilities. Softprom presents two STULZ product lines that address customer needs across different scales: the new fourth generation of TelAir 4 and WallAir 4 cooling units for telecom containers, shelters, and edge nodes — and STULZ modular container data centers for rapid deployment of computing capacity where building a traditional data center is too slow, expensive, or impossible.

Both solutions respond to the same industry trend: IT workloads are moving beyond traditional large data centers. 5G base stations, edge computing nodes, industrial sites, energy, and telecom facilities all require a stable microclimate and redundant infrastructure in a compact format, with minimal operational costs and compliance with new environmental regulations.

TelAir 4 and WallAir 4: Next-generation cooling for edge infrastructure

STULZ has introduced the fourth generation of its TelAir and WallAir series — specialized cooling units designed for telecommunications containers, shelters, radio stations, and edge data centers. The new units are built to handle the rising thermal densities of 5G and edge infrastructure while complying with the strict requirements of the updated European F-Gas Regulation (EU) 2024/573 regarding refrigerants.

The manufacturer offers two installation formats:

• TelAir 4: Designed for indoor installation. In-wall mounting protects the equipment against weather and vandalism while reducing noise emissions to levels suitable for residential and mixed-use areas.
• WallAir 4: Monoblock unit for external mounting on a container wall. Saves internal space — a critical factor for compact shelters where every centimeter is dedicated to IT equipment.

Both series are available in two standard enclosure sizes and four cooling capacity classes ranging from 6 to 17 kW.

Configuration comparison: TelAir 4 vs WallAir 4

To ensure the optimal fit for specific budgets and engineering requirements, STULZ offers two technological options:

Classic On/Off systems (TF / WF)

• Regulation: Mechanical thermostatic expansion valve (TXV)
• Features: Hermetically sealed refrigeration circuit for enhanced reliability
• Application: Stable loads with baseline temperature control requirements

Inverter systems (TV / WV)

• Regulation: Continuously modulating EC inverter compressors paired with an electronic expansion valve (EEV)
• Features: Maximum energy efficiency under variable loads and a hermetically sealed circuit
• Application: Dynamic IT workloads demanding high resource efficiency

Key advantages and EN 378 compliance safety

Utilizing Free Cooling mode allows the system to harness cold outdoor air instead of running the compressor, delivering 80% savings on operating costs. Integrated EC fans already comply with the upcoming ErP 2027 Ecodesign directive, and the standard operating temperature range from -20°C to +54°C (extendable to -40°C with an optional winter kit) makes the solution suitable for unstaffed remote locations.

The equipment operates on eco-friendly R454C refrigerant with low GWP. Since R454C is classified as A2L (lower flammability), STULZ has developed a certified EN 378 safety architecture:

• The evaporator fan is positioned at the bottom to quickly dilute and extract gas in the event of a leak.
• Two-stage sensor system: at 10% lower flammability limit (LFL), fans ramp up to maximum speed and other power consumers shut down; at 20% LFL, the unit is completely disconnected from the power supply.
• Enclosed IP54 control cabinet eliminates potential ignition sources.

The E² BASIC controller features built-in Ethernet, Modbus, and a wide range of inputs/outputs for seamless integration with BMS and DCIM systems, as well as dedicated inputs for fire, smoke, and intrusion alarms.

STULZ modular container data centers: A ready-to-use DC in weeks

A container data center is a prefabricated, factory-tested autonomous module housing IT equipment, precision cooling, power distribution, monitoring, and physical security. Instead of months of construction, the customer receives a turn-key solution that simply needs to be delivered, connected to power and network, and booted up.

Structural solution options:

• Standard ISO modules (20FT and 40FT High Cube): Transportable by any mode of transport without special permits.
• CLS modules (Cable Landing Station): Designed for submarine and trunk cable landing stations with secure connection options.
• Telecom modules for edge applications: Customized data centers for deployment near base stations and communication nodes.
• Power and cooling modules: For efficient power distribution and minimized energy consumption.
• Prefabricated Scalable Modular Data Centres: Customized all-in-one non-ISO solutions tailored to specific layout requirements.

Modular architecture enables building multiple data halls in phases, reducing initial CAPEX and guaranteeing a service life of over 20 years in harsh operating environments.

Delivery for a typical project takes under 24 weeks, allowing computing capacity to go live significantly faster than traditional construction.