PCM — Independent Commissioning Agent & Commissioning Management Perth
The Tool Box
Energy balance · CIBSE

Chilled Water ΔT Calculator

Reconcile measured flow and ΔT against rated coil duty. The fastest way to detect low-ΔT syndrome, control valve authority issues and fouled heat exchangers on site.

Energy Balance Audits

mc ΔT Energy Auditor

Energy Calculations

Result Panel

103.63Calculated Power (kW)
Fluid Medium:water
Specific Heat (Cp):4.187 kJ/kg·K
*Standard water at 20°C (Cp = 4.187 kJ/kg·K) and dry air at sea level (Cp = 1.005 kJ/kg·K, ρ = 1.204 kg/m³).

Governing Equation

Q = ṁ · Cp · ΔT

Energy balance verification — used during witnessing to reconcile measured coil duty against design intent.

Any > 10% deviation between measured and design Q is flagged for diagnostic review (low ΔT syndrome, valve authority, fouling).

Applying On-Site Energy Reconciliation

Reconciling measured flow + ΔT against rated coil duty is the fastest way to detect low ΔT syndrome, control-valve hunting and fouled heat exchangers before they cascade into plant inefficiency.

How this works

Q = ṁ · cp · ΔT. For water at ~15 °C, cp = 4.187 kJ/kg·K. Enter any two of flow, ΔT or duty and the calculator solves the third.

A measured ΔT well below design (typically < 4 °C on 6 °C design plant) is the classic signature of low-ΔT syndrome — usually caused by control valve authority, oversized coils or bypasses left open after balancing.