Customer Hot Line

Underfloor Heating Pipe Material and Application

Q1"What are the types of underfloor heating pipes?“


1. PB Pipe - PB material has excellent performance and is known as the "plastic gold".

It has the best flexibility among underfloor heating pipes, but it is also the most expensive in terms of price.

2. PEX Pipe - PEX material has good low-temperature toughness and stress-cracking resistance. It can withstand high temperatures of over 110 degrees Celsius.

3. XPAP Pipe - The aluminum layer in the middle of the aluminum-plastic composite pipe (XPAP) has oxygen barrier functionality.

However, it requires a larger bending radius, making construction more difficult, and it is also relatively expensive.

4. PP-R Pipe - PP-R pipes have a lower price and good high-temperature resistance.

However, they are difficult to bend during underfloor heating construction, and they have poor thermal conductivity.

5. PERT Pipe - PERT pipes have excellent corrosion resistance, creep resistance, and thermal conductivity. They are widely used in underfloor heating pipe materials.

Please let me know if you need further assistance or more information!

Q2"What are the brands of underfloor heating pipes?"

Suran, Akan, GF, Fanski, Macro, Ginde, Vanse, Jinniu, Rifeng, Miergu, Jomoo, Era

Q3 "What is the price of underfloor heating pipes?"

Based on the brand, whether it's imported, and whether it has oxygen barrier properties, t

here can be significant price differences for the products.

Below are approximate reference prices for 16mm diameter pipes for underfloor heating:

PB pipes: 10-20 yuan/meter

PEX pipes: 6-16 yuan/meter

XPAP pipes: 8-16 yuan/meter

PPR pipes (25mm diameter): 10-16 yuan/meter

PERT pipes: 5-10 yuan/meter

Please note that these prices are for reference only, and actual prices may vary depending on market supply and demand,

brand, quality, and other factors. When purchasing underfloor heating pipes, it's recommended to consult with suppliers for accurate pricing and product information.

Q4"Which material is good for underfloor heating pipes? A comparison of the advantages and disadvantages of different underfloor heating pipe materials?"

Meximum Temperature Resistance°C11085110
Thermal ConductivityW/m.K0.350.40.22
Linear Exapnsion Coefficientmm/m.k0.20.180.13
Thermal Exapansion Coefficient10-4/K1.81.951.3
Tensile Yield StrengthMpa1616.517
Tensile Fracture StregthMpa203433
Elongation at Break%>500>800>125
Connection Method

MechanicalMechanical, Heat FusionMechanical, Heat Fusion

Raw Material Source

Number ofProduct Categories
Complexity of Process Control
Wear Resistnace
Flexural Performance
Recycalbility of Waste
Excellent Low-Temperature Toughness, High Stress-Crack Resistance, and Strong Scratch Resistance. It has excellent heat resistance (does not melt at temperatures up to 200 degrees Celsius), and its expected service life at 80 degrees Celsius can reach up to 114 years.Easy Processing, Waste Material Can Be Recycled and Reused.Can be welded, usable temperature range is from -40 degrees to 70 degrees Celsius. It has better cold resistance than PPR and can be heat fused. It has advantages over PPR in both cold and hot water applications. At 80 degrees Celsius and 0.67MPA, it can be used for 25 years. At 95 degrees Celsius and 0.52MPA, the service life does not exceed 10 years.
PB pipes are lightweight, flexible, and have good impact resistance with a minimum bending radius of 6 times the diameter. Their molecular structure is stable. In the absence of UV exposure, their service life is not less than 50 years, and they are non-toxic. They exhibit good frost and heat resistance: at -20 degrees Celsius, they have excellent low-temperature impact resistance, preventing freezing and cracking; after thawing, the pipes return to their original state. Installation is convenient, safe, and reliable.

High Expansion Coefficient: Prolonged use can lead to cracking, especially in bends, affecting aesthetics. The bending part is prone to kinks. Waste cannot be effectively recycled.The pipe wall is relatively thin, making it more prone to bending. Stress concentration occurs at bending points, leading to potential cracking issues.It has a relatively high oxygen permeability, and PB pipes have poor scratch resistance. They are expensive to manufacture and the processing of raw materials is more challenging.

Q5“what are the different methods for fixing the heating pipes?”

(1) Secure the heating pipes directly onto the insulated panel with dedicated plastic clips that have a composite surface layer.

(2) Bind the heating pipes to a steel mesh laid on the surface of the insulation layer using nylon cable ties.

(3) Attach the pipes directly to dedicated pipe brackets or clamps laid on the surface of the insulation layer.

(4) Secure the pipes directly within the grooves formed by the raised interconnections on the surface of the insulation layer.

Q6“What are the layout forms of heating pipes?”


             Dual Parallel Arrangement                                      Parallel Arrangement                                    Fold-back Type

Q7"What is the spacing of the heating pipe?"


The spacing of the underfloor heating pipes should be determined through calculations based on the floor heat dissipation, indoor design temperature, average

water temperature, and heat transfer resistance. The pipe spacing should be around 100-300mm. The distance of heating pipes from the interior surface of external walls should be around 200-300mm, and from bathroom walls around 100-150mm. The spacing of pipes near windows can be slightly reduced. Generally, for pipes with a diameter of 16mm, the spacing is about 15cm, and for pipes with a diameter of 20mm, the spacing is about 20cm.

Q8 “Can the length of each circuit of underfloor heating pipes be different?”

Is it okay if the lengths of each circuit of heating pipes connected to the same manifold are not uniform? The lengths of each circuit should be as close as possible (with a difference of no more than 15%). If there is a significant difference in the length of each circuit, it could result in localized overheating or insufficient heating. The length of each circuit should not exceed 120 meters.

Q9"How is the bending raidus of underfloor heating pipes determined?"

The bending radius of underfloor heating pipes should not be less than 6 times the outer diameter of the pipe, and "dead folds" should be avoided.

Q10 "In areas where underfloor heating pipes are densely arranged,what issues should be considered?"

In areas where underfloor heating pipes are densely arranged, the following issues should be noted:

1. **Heat Distribution Balance:** Dense arrangement of underfloor heating pipes can affect the balanced transfer of heat, potentially leading to overheating in certain areas and insufficient heating in others. When designing and installing the pipes, ensure a proper layout to avoid uneven temperature distribution.

2. **Fluid Resistance:** Dense arrangement of pipes may increase fluid resistance within the system, impacting water circulation speed and heat transfer efficiency. Ensure the pipe layout is designed sensibly, avoiding excessive congestion to maintain an appropriate water flow rate.

3. **Maintenance and Cleaning:** Dense arrangement of pipes can make maintenance and cleaning more challenging, potentially reducing the efficiency of cleaning and maintenance tasks. When laying the pipes, leave sufficient space for regular maintenance and cleaning.

4. **Pipe Wear:** Dense arrangement of pipes can lead to friction and collisions during installation and maintenance, potentially causing surface wear or damage to the pipes. Handle the pipes with care to prevent damage.

5. **Leak Prevention:** The increased number of connections in densely arranged underfloor heating pipes requires proper sealing of connections to prevent leakage issues.

6. **Layout Rationality:** When planning the layout of densely arranged pipes, consider the actual room layout and usage requirements, avoiding interference with furniture or other facilities.

7. **Thermal Expansion and Contraction:** Densely arranged pipes may experience greater impact from thermal expansion and contraction. Ensure that the pipe layout and connections can accommodate these changes to avoid deformation or damage.

In summary, in areas with densely arranged underfloor heating pipes, it's important to consider factors such as heat distribution, fluid resistance, maintenance and cleanliness, and installation safety. This ensures the proper functioning and efficiency of the underfloor heating system. If you encounter difficulties or uncertainties in the layout design, it's recommended to consult professional underfloor heating system designers or installation companies.

Q11 " How do impurities get into the underfloor heating pipes?"


The impurities inside the underfloor heating pipes come from various factors:

1. Manufacturing process: During the manufacturing process of underfloor heating pipes, impurities may enter the pipes due to impure materials or imperfect production processes.

2. Transportation and storage: Underfloor heating pipes may be influenced by external factors such as dust and contamination during transportation and storage, leading to the presence of impurities inside the pipes.

3. Installation process: During the installation of underfloor heating pipes, if the construction environment is not clean, some impurities such as dust and soil may be introduced.

4. Water source quality: The water source in the underfloor heating system may contain certain impurities, such as rust and particles, which can deposit inside the pipes.

5. Aging and corrosion: After prolonged use, underfloor heating pipes may experience aging and corrosion, resulting in the generation of internal impurities.

To ensure the proper operation of the underfloor heating system, regular cleaning and maintenance should be carried out to remove the impurities inside the pipes and maintain the system's smooth operation and efficiency.

Q12"What are the diameter and internal hot water flow rate of the underfloor heating pipes?"

1) Under conditions where water resistance is not exceeded, higher water flow velocity reduces the likelihood of air accumulation within the pipes, aiding in lowering the heat transfer resistance and increasing heat dissipation. Generally, the water flow velocity within the pipes should not be less than 0.25 m/s, and it is recommended to maintain a velocity range of 0.25 m/s to 0.5 m/s. The water flow velocity within manifold distributors should generally not exceed 0.8 m/s. Too low a flow velocity can affect heat dissipation, while excessive velocity can burden the water pump and result in noticeable water flow noise.

2) Generally, the system water flow rate should not fall below 60% of the rated system flow rate under any circumstances. If situations arise where flow rates could drop below 60%, pressure relief bypass valves or other bypass measures should be installed to prevent potential unit protection issues.

3) In consideration of reducing water-side resistance of heating coils and enhancing heating efficiency, it is advisable to use pipes with an outer diameter of Φ20 for the heating pipeline. Taking into account ease of construction and installation, pipes with an outer diameter of Φ16 are preferable. The choice of the most suitable option should be based on the actual project conditions.

Q13“What are the methods for cleaning underfloor heating pipes?”


1. Filter Cleaning: Clean the filter at the front end of the manifold before use every year to ensure the cleanliness of the pipes and prevent blockages in the pipeline.

2. Chemical Agent Cleaning: Place chemical agents into the pipes to soak and achieve a cleaning effect. During the soaking process, scale and sediment inside the pipes are loosened, allowing for better flow and preventing water blockage.

3. Projectile Cleaning: Projectile cleaning primarily utilizes the friction between the cleaning projectile and the pipe to achieve the cleaning objective. This method is more time-consuming and labor-intensive and can be selectively used.

4. Jet Cleaning: Jet cleaning involves using a cleaning agent with corrosion inhibitors, which can effectively dissolve the adhered sludge on the pipe walls. This method doesn't cause pollution to the environment, won't corrode the underfloor heating metal pipes, and ensures thorough cleaning.

5. Physical Pulse Wave Cleaning: Pulse wave cleaning employs the vibration waves generated by mixing water and air to impact the heating pipes, achieving a cleaning effect. This method is simple and provides effective cleaning results.

Q14 “What are the factors that can affect the effective heat dissipation of underfloor heating?”

Factors that can affect the effective heat dissipation of underfloor heating include:

1. Pipe Layout and Spacing: Improper layout or spacing of heating pipes can lead to uneven heat distribution and reduced effectiveness.

2. Floor Covering: The type and thickness of the floor covering can influence heat transfer from the pipes to the room.

3. Water Temperature: The temperature of the water circulating through the pipes affects the heat output of the system.

4. Flow Rate: The flow rate of the circulating water can impact the heat transfer efficiency.

5. Insulation: Insufficient insulation beneath the heating pipes can result in heat loss downward instead of upward.

6. Floor Construction: Different floor constructions have varying thermal conductivity, affecting heat distribution.

7. Room Insulation: Poor room insulation can lead to heat loss through walls, ceilings, and windows.

8. Thermostat Settings: Incorrect thermostat settings can lead to temperature imbalances and inefficient heating.

9. Air Bubbles: Air trapped in the system can impede water circulation and reduce heat transfer.

10. Boiler Efficiency: The efficiency of the boiler or heat source affects the temperature of the circulating water.

Proper design, installation, and maintenance are crucial to ensure optimal heat dissipation in underfloor heating systems.

Q15 “Which parts of the underfloor heating pipes need to be protected?”


1. The main pipeline from the boiler to the manifold;

2. The exposed part of the pipeline at the manifold location above the ground;

3. The pipeline at expansion joints;

4. The pipeline passing through walls or areas with level differences;

5. The densely arranged pipelines beneath the manifold.

Q16 “What issues should be considered when laying heating pipes?”

When laying heating pipes, attention should be given to the following issues:

1. During transportation, ensure that the pipes are not damaged, and when storing them, avoid direct sunlight exposure to the pipes.

2. When coiling the heating pipes, avoid twisting them.

3. After completing intermittent installation of the heating pipes, seal any open ends promptly.

4. Take precautions to prevent paint, asphalt, or other chemical solvents from contaminating the pipes during the installation process.

Q17 Unreasonable pipe lengths can lead to insufficient heating in the underfloor heating system.

1. The ideal length for each circuit of the home renovation's underfloor heating pipes is about 65-75 meters. If the pipelines are too long and the water resistance increases, it can affect water circulation and lead to inadequate heating. Additionally, the lengths of each circuit should be relatively uniform, with a difference in length of no more than 5 meters. In special cases, the difference should not exceed 10 meters to ensure that water flows in and out equally and achieve temperature balance in various heating zones. Otherwise, a significant difference in circuit lengths can cause a "short circuit" phenomenon, resulting in uneven heating.

2. Insufficient pipeline pressure

   Phenomenon: Some households have tall buildings or are located at the end of the heating supply in a community, leading to insufficient pipeline pressure and inadequate heating.

   Solution: If the circulating power of the underfloor heating system is inadequate, it can result in cool return water. This is because water circulation in the underfloor heating pipes requires a certain pressure. If the pressure is insufficient, the return water may not become sufficiently hot due to inadequate circulation. In such cases, it's recommended to contact a heating company or the property management for resolution. If the issue persists, consider installing a circulation pump to improve water circulation and achieve the desired heating effect.

3. Air trapped in the pipes

   Phenomenon: The main supply pipe of the underfloor heating system is hot, while the return pipe is not. This could be due to trapped air in the pipes preventing hot water from entering the return circuit for circulation.

   Solution: Close the return valve first, then manually open the air vent on the underfloor heating system to release trapped air. Close the valves on the supply side one by one and open the air vents sequentially. During the air venting process, some water overflow may occur. Place a small basin to collect the overflowing water. After fully purging the air from the underfloor heating pipes and ensuring smooth circulation, observe the heating effect over the next half hour. Often, a lack of heating in the return pipes is related to air venting.


4. Filter clogging

   Phenomenon: The supply pipe is not heating properly, which could be due to poor water quality leading to clogging of the filter, hindering normal circulation.

   Solution: Use a wrench to open the filter and clean the filtering net inside. Reinstall the filter after cleaning, or seek assistance from professionals for cleaning.

5. Lack of regular cleaning

   Inadequate maintenance of the underfloor heating system can lead to inadequate heating. In underfloor heating systems, the pipes accumulate 1mm of scale annually on average. This 1mm layer of scale can cause a temperature drop of 6°C in the water. Additionally, the complex structure of underfloor heating systems with long pipelines, along with changes in supply water temperature, can lead to the accumulation of calcium and magnesium scale, rust, sludge, algae, etc. Neglecting regular maintenance will result in these substances adhering to the inner walls of the pipes. Over time, this can lead to a gradual narrowing of the inner diameter of the pipes, reduced water flow, temperature decline in the underfloor heating system, malfunctions, and even pipe blockages.

   Solution: In general, the underfloor heating pipes should be cleaned every 3 to 5 years. However, the frequency may vary depending on the specific circumstances. Ideally, professional underfloor heating cleaning companies should perform maintenance on the equipment before each heating season.

Q18 "How should I deal with water leakage?"

After the completion of underfloor heating construction, it is necessary to strictly adhere to the inspection, commissioning, and acceptance requirements specified in the "Technical Specifications for Radiant Floor Heating" (JGJ142-2012). There should be no water leakage issues present during this process.

Q19 “Can there be joints in the heating pipes underground?”

No, however, in case of accidental damage after construction and acceptance, repairs can be made using joints. The joints can be connected using heat fusion or clamp (press) type copper pipe joints. When using copper pipe joints, corrosion protection measures should be added externally and indicated on the completion drawings.

Q20 “Why is it said that oxygen barrier underfloor heating pipes are better?”

The presence of oxygen in the pipeline will accelerate the aging of the underfloor heating pipes and other components, reducing heat transfer efficiency and lifespan. It also promotes the growth of microorganisms, and an increasing number of microbial remains can turn into bio-slime, leading to a decrease in the heat transfer efficiency of the pipes and even blockages. Therefore, it is recommended to use oxygen barrier pipes.

Q21 Three-layer oxygen barrier vs. Five-layer oxygen barrier?


Currently, there are two types of oxygen barrier pipes available in the market: three-layer oxygen barrier pipes and five-layer oxygen barrier pipes. Both types of oxygen barrier pipes use Ethylene-Vinyl Alcohol copolymer (EVOH) as the oxygen barrier layer. The structure of the five-layer oxygen barrier pipe is: resin/ adhesive/ oxygen barrier layer/ adhesive/ resin. Since the oxygen barrier layer is positioned in the middle of the pipe, it has excellent impermeability and is not prone to damage, ensuring effective oxygen barrier performance.

Q22 “How to distinguish between genuine and fake oxygen barrier underfloor heating pipes?”

1. Appearance: PE-RT pipes or PEX underfloor heating pipes with an outer layer containing an oxygen barrier layer have a smooth and glossy appearance.

2. Cutting with a Blade: Usually, oxygen barrier layers containing EVOH are not allowed to have added color masterbatch. By cutting open the oxygen barrier underfloor heating pipe with a blade, you can see that the outer layer is the natural color EVOH layer, the middle layer is the colored adhesive layer, and the innermost layer is the PE-RT or PEX layer. However, this method should not be used to identify fully natural-colored oxygen barrier layers.

3. Water Test: Some manufacturers use PE instead of EVOH to produce oxygen barrier PE-RT pipes or PE-X pipes. To differentiate these products, you can use the principle that "EVOH has a density greater than 1, while PE has a density less than 1." Place a slice of the oxygen barrier layer in water and observe if it sinks or floats.

4. Iodine Test: If genuine EVOH oxygen barrier material is used, applying iodine tincture to the surface of the oxygen barrier layer will cause EVOH to dissolve rapidly, whereas non-oxygen barrier materials will not dissolve.

5. Extrusion Machine Count: Since oxygen barrier underfloor heating pipes require at least three different materials – PE-RT or PE-X, oxygen barrier layer, and adhesive – a factory must have at least three extrusion machines. If the number of extrusion machines is less than three, then the factory likely cannot produce oxygen barrier underfloor heating pipes.

Q23"What are the types of connection methods for underfloor heating pipes?"

There are two types of connection methods for underfloor heating pipes in China: heat fusion and mechanical connection. Mechanical connection includes

quick coupling, compression fitting, and clamping, among others.

Q24 “How to Determine If Underfloor Heating Pipes Need Cleaning?”


       cleaned                                    not cleaned

1. Abnormal Coloration: The inner walls of the manifold connecting pipes appear yellow, green, reddish-brown, black, etc. This is due to the long-term deposition and adherence of calcium and magnesium ions scale and biological slime on the inner walls of the pipes.

2. Lower Room Temperature: The indoor temperature has been gradually decreasing over the years. This is because the scale buildup on the inner walls of the pipes hinders the transfer of temperature.

3. Reduced Flow Rate: The water flow rate through the underfloor heating pipes is lower than in previous years. This is caused by excessive biological slime buildup inside the pipes leading to local narrowing. Failure to clean can result in pipe blockages and inability to use.

4. Slow Water Flow: When draining each pipeline individually, some pipelines have slow water flow or even no water flow. This is due to pipe narrowing or blockages.

5. No Cleaning for Many Years: No cleaning has been conducted for more than three heating seasons, generally cleaning is recommended every 2-3 heating seasons.

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