Engineering Calculation Tools
This chapter provides interactive calculation tools to assist engineers in sizing system components, estimating energy consumption, and evaluating economic feasibility. These tools implement industry-standard formulas and best practices to ensure accurate results.
1. Cooling Load Calculator
Calculate the total cooling load based on IT equipment power, facility loads, and safety factors.
2. Airflow Rate Calculator
Calculate the required airflow rate based on cooling load and temperature rise.
Typical range: 10-15°C (cold aisle to hot aisle)
3. PUE and Energy Savings Calculator
Estimate annual energy consumption and cost savings from improved PUE.
4. Free Cooling Hours Estimator
Estimate annual free cooling hours based on climate data and supply air temperature setpoint.
Outdoor temp must be below (Supply Temp - Differential) for free cooling
9.1 Formula Reference
The following formulas are used in the calculation tools above:
9.1.1 Cooling Load Calculation
- Actual IT Load: Q_IT = P_rated × U_factor
- Lighting Load: Q_lighting = Lighting_density × Floor_area / 1000
- UPS Loss: Q_UPS = Q_IT × UPS_loss_factor
- Total Design Load: Q_total = (Q_IT + Q_lighting + Q_UPS) × Safety_factor
9.1.2 Airflow Rate Calculation
- Airflow Rate: Q_air (m³/h) = Q_sensible (kW) × 3600 / (ρ × Cp × ΔT)
- Where: ρ = 1.2 kg/m³ (air density), Cp = 1.005 kJ/kg·K (specific heat)
- Simplified: Q_air ≈ Q_sensible × 2985 / ΔT
9.1.3 PUE and Energy Calculation
- Total Facility Power: P_facility = P_IT × PUE
- Annual Energy: E_annual = P_facility × 8760 hours
- Annual Cost: Cost = E_annual × Electricity_rate