Industrial Sizing Solutions: The Trotec PT 23000 S for Server Room Cooling

A server room that exceeds its thermal design point does not fail gradually. It fails suddenly: a DIMM module reaches its junction temperature limit, throttles to 30 percent of performance, and the application it supports goes into timeout. Two minutes later the storage controller on the adjacent server does the same. By the time the monitoring dashboard shows red, the damage may already be done — not to the hardware, which modern equipment protects with thermal throttling, but to the services that depended on it remaining at full capacity.

The Trotec PT 23000 S is a commercial-grade portable spot cooler designed for exactly this environment: high-density heat loads in constrained spaces where fixed CRAC (computer room air conditioner) infrastructure either does not exist, has failed, or requires a portable supplement during maintenance windows. Understanding how to size, deploy, and redundancy-plan a unit like the PT 23000 S requires different calculations from the residential cooling sizing that most portable AC buyers are familiar with.

What is the Trotec PT 23000 S and what distinguishes it from residential portable ACs?

The Trotec PT 23000 S is a large-capacity portable spot cooler rated at approximately 23,000 BTU/h (roughly 6.7 kW) of cooling output, designed for continuous operation in commercial environments with high sensible heat loads. Where residential portable ACs are designed for 8 to 12 hours of daily cycling use in dust-light environments, the PT 23000 S is built for 24/7 operation in server rooms, print and production areas, and temporary works enclosures — environments with continuous high heat output, elevated airborne particulate, and no tolerance for unplanned downtime.

Key differences from residential units include: a higher-capacity compressor and heat exchanger sized for continuous full-load operation; ducted hot air discharge designed to connect to flexible ducting that routes exhaust heat out of the cooled space; a condensate management system capable of handling the continuous high condensation rates produced by cooling dense electronic loads; and a reinforced chassis rated for repeated repositioning in commercial environments. The electrical supply requirement — typically 16 A single-phase at 230 V — is within standard commercial socket specification but above what a domestic 13 A socket can sustain continuously.

How do you calculate the cooling requirement for a server room?

Server room heat load calculation begins with a simple identity: every watt of electrical power entering an IT space leaves as heat. A server consuming 400 W of electricity at the PSU input produces 400 W of heat inside the room. A rack of twenty servers at 400 W each produces 8,000 W (8 kW) of heat. This is the dominant load in any IT space, and it is determined entirely by measuring or specifying the total electrical consumption of the installed equipment — not the BTU capacity of the servers' published thermal design points.

To this base IT load, add secondary heat sources: lighting (typically 5 to 15 W per square metre for LED-fitted server rooms), people (approximately 100 W per person present), and heat conducted through the building envelope (calculated using standard U-value and area methods for the specific construction). For most small to medium server rooms where the IT load dominates, these secondary sources add 5 to 15 percent to the total. A conservative planning factor of 1.15 times the measured IT load gives the minimum cooling capacity required.

The ASHRAE thermal guidelines for data centre equipment (ASHRAE Technical Committee 9.9, Guidelines for Data Center Environments, 2021) specify recommended inlet air temperatures of 18 to 27°C for Class A2 equipment (the most common server classification), with allowable inlet air humidity between 20 and 80 percent relative humidity. These constraints define the cooling system's output specification: deliver air at 18 to 22°C to equipment inlets, and maintain that temperature under the full design IT heat load.

The N+1 notation in the table refers to redundancy design: N units provide the required cooling capacity, with one additional unit available to replace any single failed unit without service interruption. N+1 is the minimum redundancy standard for any server room where planned or unplanned cooling maintenance cannot be tolerated as downtime. For the Trotec PT 23000 S at approximately 6.7 kW cooling, a 7.5 kW IT load requires two units to achieve N+1 — one running, one on standby.

How do you correctly position a portable spot cooler in a server room?

The PT 23000 S discharges cold air through a directional outlet and exhausts hot condenser air through a duct connection at the rear. The exhaust duct must be routed outside the cooled space — through a ceiling tile, a wall penetration, or a door gap — to prevent the rejected heat from recirculating back into the server room and negating the cooling effect. This is the single most common deployment error: an unducted or partially ducted portable spot cooler exhausting hot air into the same room it is cooling will achieve zero net cooling while consuming full electrical power.

For server rooms using hot-aisle/cold-aisle containment (a layout strategy that separates equipment intake airflow from exhaust airflow by alternating rack face orientation), the PT 23000 S cold air outlet should be directed into the cold aisle — the aisle where server intake faces are located. The hot exhaust duct should penetrate through or above the hot aisle containment to the building's air handling system or directly outside. This deployment allows the spot cooler to feed precisely the air stream that servers draw, maximising the fraction of cooling capacity that reaches equipment intakes.

The edge case: portable cooling as emergency N+1 for a failed fixed CRAC unit

The highest-value use case for a portable commercial spot cooler in many organisations is not primary cooling but emergency redundancy. A data centre or server room with a single fixed CRAC unit has a latent N+1 deficit: if the CRAC fails, there is no backup. A Trotec PT 23000 S or equivalent commercial portable unit stored in a nearby equipment room, with a pre-measured flexible exhaust duct sized to reach the server room's exhaust pathway, can be deployed in 10 to 20 minutes to restore the cooling needed to sustain critical services while the CRAC is repaired. The capital cost of the portable unit (typically €2,000 to €4,000 for commercial-grade capacity) is small relative to the cost of a service disruption lasting even one hour in a commercial IT environment. Organisations that route the portable unit's exhaust duct through a dedicated conduit installed during the original server room build can achieve sub-five-minute emergency deployment — a response time that prevents any thermal throttling event from reaching the service layer.

What are the electrical and infrastructure requirements for the PT 23000 S?

The PT 23000 S requires a dedicated 16 A single-phase 230 V supply, ideally from a circuit protected by a Type C MCB to accommodate the motor inrush at start-up. In a server room with UPS (uninterruptible power supply — battery-backed power conversion that sustains output during mains failure) coverage for IT equipment, the portable cooler's supply should also be fed from UPS-backed power if the cooling is to sustain operation during a mains outage. A 6.7 kW cooling unit at approximately 2.2 kW input power requires a UPS with sufficient capacity to sustain both IT load and cooling load simultaneously.

Condensate management is a second infrastructure consideration. The PT 23000 S generates substantial condensate from the large latent heat load it processes in a server room environment (electronics produce low-humidity exhaust heat, but the cooling process itself condenses moisture from the air). The unit should either be connected to a continuous gravity drain or fitted with an integral condensate pump and discharge line routed to a nearby floor drain. Leaving the condensate tank to fill and trigger a full-float shutdown is not acceptable for a unit deployed in a critical cooling role — the unit will switch off automatically when the tank is full, precisely when cooling is most needed.

In r/AskEngineers discussions on small data centre cooling, engineers consistently recommend sizing portable spot coolers for commercial server rooms at 120 to 130 percent of the total measured IT load rather than the nameplate capacity of installed equipment, correctly accounting for future load growth and the secondary heat sources that spec-sheet calculations often overlook.

How does commercial portable cooling compare to fixed CRAC investment?

For permanent small server rooms with stable IT loads, a fixed CRAC unit typically provides better long-term value than a portable unit in primary cooling service: fixed units have higher COP (because they can use larger, more efficient heat exchangers), lower noise, and dedicated supply and return air paths designed into the room. The PT 23000 S and similar commercial portable units serve a different economic niche: scenarios where fixed infrastructure investment cannot be justified (temporary deployments, rented facilities, proof-of-concept IT environments) or where rapid deployment speed outweighs the efficiency and cost advantages of permanent installation.

For organisations that already have fixed cooling and are evaluating portable units purely for N+1 redundancy, the cost calculation is straightforward: the portable unit only needs to run for the duration of a CRAC repair event, not continuously. Its lower COP compared with the fixed unit does not matter during an emergency; its ability to be operational in minutes rather than the weeks required to procure and install a replacement CRAC matters entirely.

High-capacity commercial portable cooling units such as the Trotec PT 23000 S serve a specialist market where stock levels are more stable than in the consumer portable AC segment. Consumer-grade portable split units — the Midea PortaSplit and equivalent European mobile split models — face far more aggressive demand spikes during summer heatwaves, selling out within hours of appearing in stock at major retailers.