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Answers and frequently asked questions

Here you can find the answers to frequently asked questions. We are always working on extending this area for you. If you cannot find the answer to your issue, do not hesitate to get in touch with us.

  • What is district heating?

    District heating is the term for the delivery of heat to supply buildings with space heating and hot water. Thermal energy is transported in thermally insulated pipe systems, which are primarily laid underground.

    Go to our district heating products​​​​​​​

  • What is the difference between local and district heating?

    The difference between local and district heating is generally a linguistic one. The term local heating is used to describe smaller, decentralised heating networks, whereas district heating refers to larger networks that generally have large transport pipes. Go to our district heating products.

  • What does the term CALPEX refer to?

    The name refers to our low-temperature flexible pipe system. It is a combination of the Italian word calore (heat) and PEX. In our product range, the carrier pipe is made from PEX plastic (cross-linked polyethylene).

    Go to the CALPEX product range.


  • What does PEX stand for?

    PE is the abbreviation for polyethylene and the X refers to cross-linking.

    This makes a particularly robust plastic pipe, which we use as an inner pipe in our CALPEX range.

  • What does PUR-KING refer to on the new CALPEX?

    What does PUR-KING refer to on the new CALPEX?

    The name refers to the PUR foam, which is used in the CALPEX product range and ensures exceptionally low thermal losses. The lambda value is currently an outstanding 0.0199 W/m*K.

    Go to the CALPEX PUR-KING product range.


  • What is a lambda value?

    The lambda value describes the thermal conductivity of a material and is one of the most important values for assessing the suitability of a substance for energy-efficient construction and renovation. Go to the CALPEX PUR-KING product range.​​​​​​​

  • What is a U value?

    The U value is a thermal transmittance coefficient used to specify the thermal insulation in pipe construction. The thermal transmittance unit is: W/m2K. This indicates how much heat (in watts W) per square metre (m2) flows through a component between the inside and outside for each degree of difference in temperature (in kelvin K).

  • What insulation materials are there?

    Main types of insulated pipes for local and district heating
    The insulated pipes needed for transporting hot water can be divided into two broad categories: rigid and flexible pipe systems. Both have their advantages and disadvantages, and the decision about which pipe system should be used in each individual case depends on the specific technical requirements.

    To the detailed report