The container body itself is made of metal, which has excellent thermal conductivity. Without effective thermal insulation measures, the problems of hot summers and cold winters cannot be solved. The proper selection and scientific installation of insulation materials are the core guarantees for the environmental comfort of a container house. This article, referencing industry standards, systematically introduces mainstream insulation materials, thickness selection, thermal break design, and key construction points.
1. Comparison of Mainstream Insulation Materials
Three types of insulation core materials are most commonly used in container buildings today, each with its own advantages and disadvantages:
| Material | Thermal Conductivity (W/(m·K)) | Fire Rating | Advantages | Disadvantages |
|---|---|---|---|---|
| Rock wool | <0.041 | Class A (non‑combustible) | Excellent fire performance, high fire resistance limit | Relatively high moisture absorption |
| Polyurethane (PU) | 0.022 | Typically Class B2 | Excellent insulation, seamless spray application | Lower fire rating |
| Extruded polystyrene (XPS) | 0.028-0.039 | Class B1 optional | Very low water absorption, outstanding moisture resistance | Poorer air permeability |
| Aerogel composite | 0.015-0.020 | Class A | Ultra‑thin and efficient, space‑saving | Higher cost |
| Vacuum insulation panel (VIP) | 0.004-0.008 | Class A | World‑leading insulation performance | Very expensive, cannot be cut |
Recommended advanced material: An aerogel composite only 3 cm thick can achieve the same insulation effect as 10 cm of traditional material, making it particularly suitable for space‑constrained container renovation projects.
2. Insulation Thickness Selection
The appropriate insulation thickness must be calculated according to the climate zone of the project location. The commonly used formula in the industry is R = δ/λ (where R is thermal resistance, δ is material thickness, and λ is thermal conductivity).
Cold northern regions: Recommended wall thickness of 75‑100 mm.
Hot summer and warm winter southern regions: A thickness of 50 mm is generally sufficient to meet insulation needs.
Roof insulation: A double‑layer staggered seam installation can further reduce heat loss caused by thermal bridging.
3. Thermal Break Design and Key Construction Points
Thermal break design is a top priority in insulation work – that is, placing insulating pads between the steel frame and the insulation material to prevent metal components from directly connecting the interior and exterior, forming a heat conduction path.
Construction essentials:
All assembly gaps and gaps around doors and windows must be filled with polyurethane foam.
Apply weather‑resistant sealing tape (e.g., butyl tape) on the outside and cover with metal battens to ensure overall airtightness.
A common wall construction is the "outer colour steel sheet + rock wool layer + inner magnesium oxide board" sandwich panel, bonded with structural adhesive and double‑fixed with rivets to ensure tight bonding of the layers.
4. Configuration Recommendations for Different Climate Zones
Severely cold regions (e.g., Northern Europe, Canada): Recommend 100 mm thick high‑density rock wool or polyurethane, combined with thermal break framing and double sealing.
Hot and humid regions (e.g., Southeast Asia, southeastern United States): Recommend XPS or closed‑cell polyurethane, with emphasis on a moisture barrier and vapour retarder.
Hot and dry regions (e.g., Middle East, inland Australia): Recommend reflective insulation coatings combined with rock wool or aerogel to reduce solar heat gain.
Chengdu Fangda Magic House's Insulation Practice
Chengdu Fangda Magic House provides differentiated configurations of various materials – including rock wool, polyurethane, XPS, and even aerogel – according to the environmental climate of different target markets. The company has delivered customised insulation solutions to customers in more than 30 countries, ensuring comfortable indoor temperatures for container houses under all climatic conditions.
