Energy Balance & Thermal Loss Assessment
Energy balance thermography quantifies heat losses from furnaces, boilers, refractory structures, steam lines, hot vessels, and thermal equipment. Temperature distribution is measured and converted into actual energy-loss values (kW), enabling cost-impact calculations and ROI modelling for insulation repair.
What an Energy Balance Audit Delivers
A standard thermographic survey identifies where heat is being lost. An Energy Balance Audit goes further — it quantifies how much, in measurable engineering units (kW, GJ/annum) and translates those figures into annual Rand cost at your energy tariff.
- Thermographic surface temperature mapping across the system
- Heat flux calculation per identified loss point (W/m²)
- Aggregated heat loss model across the full system envelope
- Annualised energy cost of current losses
- Remediation options with estimated cost and payback period
- Prioritised improvement schedule for maximum return
Methodology and Engineering Basis
All calculations follow recognised heat-transfer theory and ISO 18434-1 methodologies. Heat loss is calculated using the surface resistance method, where surface emissivity, geometry, ambient wind speed, and surface temperature determine radiated and convected heat flux per unit area.
For cylindrical geometry (pipes), calculations are based on ISO 12241. For flat surfaces (vessel walls, furnace panels), surface heat flux is derived from the ASTM C680 method. All derived values are clearly distinguished from measured data in the report.
Engineering Equations Applied
1. Stefan–Boltzmann Radiation
Qᵣ = ε × σ × A × (Tₛ⁴ − Tₐ⁴)
σ = 5.670×10⁻⁸ W/m²·K⁴
2. Convection Heat Loss
Q꜀ = h × A × (Tₛ − Tₐ)
h = convective coefficient
3. Conduction Through Lagging
Qₖ = (k × A × ΔT) / d
k = thermal conductivity
Worked Example: Furnace Surface Heat Loss
Input Parameters
- Surface temperature (Tₛ): 165°C
- Ambient temperature (Tₐ): 25°C
- Area (A): 2.4 m²
- Emissivity (ε): 0.92 (painted steel)
Calculated Results
- Radiation loss: 1.45 kW
- Convection loss: 0.68 kW
- Total estimated loss: 2.13 kW
- Cost impact (continuous): R 4,600 – R 6,000 / month
These values allow clients to quantify energy waste, justify insulation projects, and benchmark furnace performance over time — directly supporting ISO 50001 energy-management workflows.
Audit Applications
Industrial Furnaces & Kilns
Refractory hot-spot mapping, shell heat loss quantification, and door seal assessment with annualised fuel cost calculation.
Boilers & Steam Systems
Boiler casing, steam distribution, steam trap losses, and condensate system heat loss aggregated into a full system energy model.
Ovens & Dryers
Process oven panel integrity, door seal losses, and exhaust heat recovery opportunity identification.
Refrigeration & Cold Chain
Cold room panel insulation value assessment, door seal thermal mapping, and refrigeration load impact of insulation failure.
Building Thermal Envelope
Heat gain through roofing, walls, and glazing in climate-controlled facilities, supporting HVAC load reduction strategies.
ISO 50001 Support
Energy audit documentation aligned with ISO 50001 requirements, including baseline establishment and improvement opportunity register.