Bill of Materials & Cost Estimation
Automatic BOM generation with material quantities, weights, and cost estimation based on configurable material prices.
1. Overview
The BOM & Cost module automatically calculates material quantities and weights for every component of the heat exchanger based on the coil geometry. It provides a detailed breakdown of tubes, fins, casing, headers, and U-bends, with cost estimation using configurable material prices per kilogram.
2. BOM Components
| Component | Material | Calculation Basis |
|---|---|---|
| Tubes | Copper, Cu-Ni, Aluminum | Total tube length × cross-section area × density |
| Fins | Aluminum, Copper | Number of fins × fin area × thickness × density |
| Casing | Galvanized Steel | Perimeter × depth × sheet thickness × density |
| Headers | Copper, Steel | Header diameter × length × wall thickness × density |
| U-Bends | Same as tubes | Number of bends × bend length × tube cross-section × density |
3. Cost Metrics
The module provides several cost metrics for comparison and decision-making:
- Total Material Cost: Sum of all component costs
- Cost per kW: Material cost divided by total capacity ($/kW)
- Cost per TR: Material cost divided by capacity in tons of refrigeration ($/TR)
- Total Weight: Sum of all component weights (kg)
Cost per kW is the most useful metric for comparing different coil configurations. A lower cost/kW means better material efficiency for the same cooling or heating capacity.
4. Configuring Material Prices
Material prices can be configured in the Company settings (admin area). Default prices are based on typical market values, but you should update them to reflect your actual procurement costs:
| Material | Default Price | Unit |
|---|---|---|
| Copper Tube | $8.50 | USD/kg |
| Aluminum Fin | $2.80 | USD/kg |
| Galvanized Steel | $1.20 | USD/kg |
Note: The BOM estimates material cost only. Labor, overhead, shipping, and margin are not included. Use these estimates as a baseline for quoting, not as final prices.
5. Cost Breakdown Chart
A visual pie chart shows the cost distribution across components. In most coils, copper tubes represent 50–70% of the material cost, followed by aluminum fins at 15–30%. This visualization helps identify where material optimization has the greatest impact.