Project Overview

Traditional computer rooms often rely on high-energy-consuming air-cooled precision air conditioning systems, with PUE values typically exceeding 1.6. Driven by China’s "Dual Carbon" strategy, the industry is accelerating innovations in natural cooling and refrigeration technologies to address energy efficiency challenges posed by expanding data center demands. Evaporative cooling technology, renowned for its efficient use of natural cold sources, has gained widespread adoption. Among these solutions, Aolan modular cooling unit systems have emerged as a mainstream energy-saving retrofit solution due to their significant efficiency improvements.

This retrofit project focuses on upgrading water-curtain fresh air systems for two floors: the 2F large computer room and the 3F government cloud computer room.

2F Large Computer Room: Area: 228 m², IT power load: 96.66 kW.Equipped with 3 precision air conditioners (30 kW cooling capacity each, total 90 kW). Neatly arranged server racks.

3F Government Cloud Computer Room: Area: 228 m², IT power load: 40.52 kW.Contains 2 closed cold/hot aisle DC pods (1 unused).Each pod equipped with 6 row-based air conditioners (25 kW cooling capacity each, total 150 kW per pod).

Retrofit Plan

2F Large Computer Room

Design temperature: 28°C, air supply/return temperature difference: 12°C → Water-curtain fresh air handling units must provide outlet air below 16°C.  Based on Ganzi’s annual hourly meteorological data, water-curtain systems can operate year-round.

Configuration:

l 5 water-curtain fresh air handling units.

l G4 external filters installed on four-sided air inlets.

l Units suspended above the north corridor; supply ducts penetrate walls into the room.

3F Government Cloud Computer Room

Hot aisle design temperature: 32°C, air supply/return temperature difference: 12°C → Water-curtain fresh air handling units must provide outlet air below 20°C. Year-round operation feasible per Ganzi’s climate data.

Configuration:

l 2 water-curtain fresh air handling units.

l G4 external filters on four-sided air inlets.

l Units suspended above the north corridor; supply ducts penetrate walls into the room.

Performance Results

Pre-retrofit annual energy consumption: 244,176 kWh.

Post-retrofit annual energy consumption: 68,715 kWh.

Annual energy savings: ~175,000 kWh (71.9% reduction).

Key Advantages

1. The most direct utilization of natural cold sources, especially suitable for communication machine rooms and other places with year-round cooling demands, is currently the best way to reduce the PUE value for communication machine rooms.

2. Low power consumption. In winter, the power consumption can be as low as 20% of that of a precision air conditioner. The drier the outdoor air and the lower the temperature, the more energy savings are achieved.

3. It has its own dehumidification capability, eliminating the need for an additional humidifier and saving electricity during the dehumidification process.

4. Energy-saving and power-saving, reducing carbon emissions; without chlorofluorocarbons, it does not damage the ozone layer, environmentally friendly.

Notes:

PUE (Power Usage Effectiveness): A metric for data center energy efficiency (lower values = higher efficiency).

"Dual Carbon" Strategy: China’s national initiative to peak carbon emissions by 2030 and achieve carbon neutrality by 2060.