For insulating PPR pipes, especially hot water pipes in home renovations, the recommended solution is rubber-plastic insulation cotton. This material has a low thermal conductivity (approximately 0.034 W/m·K), and its closed-cell structure makes it extremely moisture-proof, resistant to condensation, and easy to cut and install, offering excellent value for money.
When purchasing, it is recommended to look for B1-grade flame-retardant products, with a thickness of 15mm or 20mm, and the inner diameter must match the outer diameter of the PPR pipe (e.g., 20mm for a 4-point pipe). If higher insulation performance and lifespan are required, such as for main heating pipes, polyurethane integrated insulation pipes can be used-they offer top-notch insulation performance, good waterproofing, and a lifespan of over 30 years, but are more expensive and not suitable for later installation. Rock wool pipes have the best fire resistance (non-combustible), but they are extremely absorbent of water, which significantly reduces their insulation performance. Therefore, they are only suitable for dry environments and require proper external waterproofing. Polyethylene (PEF) is environmentally friendly and resistant to acids and alkalis, but its insulation performance is average, and its flexibility is not as good as that of rubber-plastic insulation cotton. In actual construction, it is crucial to ensure a tight fit between the insulation material and the pipes. Longitudinal seams and transverse joints must be sealed tightly with specialized aluminum foil tape. Elbows, tees, valves, and other details must also be carefully wrapped, leaving no blind spots.
Two points to note:
First, in humid environments or for air conditioning condensate pipes, always use closed-cell rubber-plastic insulation to prevent condensation at the source.
Second, the fire resistance rating of insulation materials used in home renovations should at least meet the national standard B1 (flame-retardant) to ensure safety.
In summary, rubber-plastic insulation is the preferred choice for ordinary household hot water pipes, balancing performance, cost, and ease of installation.