Technical Specifications

Designing a Liebert XD Solution
14
Example
For example, a 2000 ft
2
server room with has 30 racks, 15 racks produce 20kW of heat each and 15
produce 10kW of heat per rack.
1. Calculate the total sensible cooling load.
15 racks x 20kW/rack = 300kW
15 racks x 10kW/rack = 150kW
300kW + 150kW = 450kW
The total room load is 450kW.
2. Check heat density per square foot:
450kW/2000ft
2
= 0.225kW/ft
2
= 225W/ft
2
3. Determine base cooling requirements:
Typically, perimeter cooling accounts for 2 to 5kW per rack.
2kW x 30 racks = 60kW
Based on 2kW/rack, 60 kW will be handled by the perimeter cooling.
4. Determine Liebert XD cooling requirements:
450kW - 60kW = 390kW
Three Liebert XDP160s would be needed.
5. Calculate the Liebert XDP reserve capacity:
390kW/3 Liebert XDP160s = 130kW
Each Liebert XDP, on average, would bear 130kW of the heat load.
130kW / 160kW = 81% of maximum load
This Liebert XD solution has 19% reserve capacity.