FAQ - CRAC/CRAH

Question 1

What is the difference between CRAC and CRAH?

Accepted Answer

CRAC (Computer Room Air Conditioning) has an integrated compressor and works with direct expansion of refrigerant gas. CRAH (Computer Room Air Handler) uses a chilled water coil supplied by a central chiller. CRAC is ideal for smaller data centers, while CRAH offers greater efficiency in large facilities.

Question 2

What is the ideal temperature for a server room?

Accepted Answer

ASHRAE recommends temperatures between 18°C and 27°C for data centers, with an ideal range of 20°C to 22°C. Relative humidity should be between 40% and 60%. Our CRAC/CRAH equipment maintains these parameters with ±0.5°C and ±3% RH precision.

Question 3

What is N+1 redundancy in data center HVAC?

Accepted Answer

N+1 redundancy means having one additional unit beyond what is required. If your data center needs 3 CRAC units for the thermal load (N=3), you install 4 units (N+1). This way, if one fails, the other 3 handle the load without interruption.

Question 4

How does free-cooling work in data centers?

Accepted Answer

Free-cooling uses cold outside air to cool the data center, reducing or eliminating compressor use. When the outside temperature is below a setpoint (e.g., 15°C), the system uses outside air directly. This can reduce energy consumption by 30-50% depending on the climate.

Question 5

What cooling capacity do I need for my data center?

Accepted Answer

Sizing considers: IT load (server kW), lighting, people, infiltration and safety factor. Rule of thumb: for every 1 kW of IT load, consider 1.2 to 1.5 kW of cooling. Our engineering team performs detailed calculations according to ASHRAE standards.

Question 6

Can CRAC/CRAH be integrated with BMS?

Accepted Answer

Yes, all our CRAC/CRAH equipment has interfaces for integration with BMS (Building Management System) via Modbus, BACnet or SNMP protocols. This enables centralized monitoring, alarms, data history and energy optimization.

Question 7

What PUE can be expected with Helioterm CRAC/CRAH equipment?

Accepted Answer

With our state-of-the-art equipment (EC fans, free-cooling, VFD), it is possible to achieve PUE of 1.3 to 1.5 depending on climate and design. Data centers with free-cooling in mild climate regions can achieve PUE below 1.3.

CRAC/CRAH

Main Features

Available Versions

Benefits

High Precision

High Availability

Energy Efficiency

Monitoring

Applications

Frequently Asked Questions

Need more information?