Water Curtain Fresh Air Energy-Saving Retrofit Project for a Equipment Building in Shandong

Project Overview

According to relevant national policy requirements, the compliance rate of PUE for data centers and core equipment buildings must exceed 70% by the end of 2023 and achieve 100% compliance by the end of 2025. Addressing the common issues of high heat generation in computer rooms and persistently high PUE values in core equipment buildings across Shandong Province, and to accelerate the implementation of this year's energy consumption control targets, the plan involves introducing multiple sets of evaporative air coolers. This equipment utilizes cooling pad evaporative cooling technology to enhance energy efficiency, while also featuring air filtration capabilities that effectively ensure air cleanliness in communication equipment rooms.

Operational Modes

This project includes core equipment buildings in 2 cities in Shandong Province, both utilizing the Aolan Water Curtain Fresh Air Energy-Saving Retrofit System. The system includes evaporative air coolers for supplying cooled air, negative pressure exhaust fans for expelling hot air, and an intelligent control system. The Jinan equipment room area is 550㎡ with an IT power of approximately 155kW; the Dezhou equipment room area is 542㎡ with an IT power of approximately 29kW.

Outdoor fresh air is filtered and cooled by evaporative cooling before being supplied indoors. The hot and humid air from the equipment room is forcibly expelled outdoors by the negative pressure exhaust fans. The intelligent control system collects indoor and outdoor temperature and humidity parameters via sensors and controls the operation of the water curtain fresh air system and the original room's precision air conditioners based on these parameters. When the equipment room's temperature and humidity requirements can be met, the system prioritizes operating the water curtain fresh air system to extend the utilization time of natural cooling sources and reduce the runtime of the precision air conditioners, in order to achieving the goal of energy saving and consumption reduction.

The cooling system for this project's equipment rooms includes 3 operational modes:

1.Dry Condition Fresh Air Mode: Under low outdoor temperature conditions, the evaporative air coolers and exhaust fans operate, intake and exhaust dampers open. Low-temperature outdoor fresh air is filtered and supplied into the equipment room, while hot, humid air is expelled by the exhaust fans. The fans operate at low frequency based on the indoor temperature.

2.  Wet Condition Evaporative Cooling Fresh Air Mode: Under suitable climate conditions, the evaporative air coolers and exhaust fans operate, intake and exhaust dampers open. Outdoor fresh air is filtered, evaporatively cooled, and then supplied into the equipment room. Hot, humid air is expelled by the exhaust fans. The fans operate with variable frequency based on the indoor temperature.

3.  Linked Precision Air Conditioner Mode:  When outdoor conditions are hot and humid, the water curtain fresh air system cannot meet the indoor temperature and humidity requirements, the water curtain fresh air system stops operation, and the intake/exhaust dampers close. The original equipment room precision air conditioning system is activated linked, operating according to its original design parameters in an indoor air recirculation cooling mode.

Results Demonstration

The project is started running in 2025. After commissioning, it is expected to run in good condition, maintaining a stable temperature and humidity environment in the equipment rooms. It is projected that the annual electricity consumption for the Jinan equipment room's air conditioning system will decrease from 681,000 kWh to 293,000 kWh, achieving an energy saving rate of 56.9%. The PUE is expected to drop from 1.67 to 1.38. For the Dezhou equipment room, the annual electricity consumption for the air conditioning system is projected to decrease from 164,000 kWh to 63,000 kWh, achieving an energy saving rate of 61.9%. The PUE is expected to drop from 1.83 to 1.43, demonstrating significant energy-saving effects.