Can Polymer Pipe Improve District Heating Sustainability?

Though electricity generation often takes centre stage in the journey to Net Zero, heating is another crucial area to consider. This is where district heat networks are emerging as a key solution. Such systems consist of a centralised heat source that supplies heating and hot water to multiple dwellings through underground pre-insulated pipes.

District heating pipe prices, sustainability and installation are all key considerations for the construction sector. Thanks to using one large central plant, it is easier to maintain and offers economy of scale for that heat source. Most importantly, district heating benefits in its ability to work with low carbon applications and save energy.

As we move away from third generation heat networks powered by fossil fuels, fourth generation schemes offer a lower operating temperature for increased energy savings. These lower temperatures are ideal for low carbon heat sources such as heat pumps, along with other means of renewable heating including waste heat and solar thermal energy.

The Promise of Polymer

It's clear that heat networks can play a significant role in reducing carbon emissions. At the same time however, it must be kept in mind that material choice in district heating pipework is important for maximising performance.

While traditionally made of steel, polymer district heating pipes are emerging as an alternative choice. As the latter suits lower flow temperatures, heat losses can be reduced to improve energy efficiency.

REHAU's large diameter reinforced polypropylene (PP-R) has a material lifespan of over 50 years, and can provide heat loads of up to 16MW for underground heating pipes. Unlike steel, there is minimal risk of the inner pipe corroding, which can cause network failures and disruption.

PE-Xa pre-insulated flexible pipes can be easily utilised to fulfil the requirements of most builds. This trait, combined with the innate durability of PE-Xa, demonstrates how polymer can help futureproof the way heat is generated for buildings.

Reducing the Burden

It’s not just in practice that polymer could make pipeline heating systems more sustainable. The material also has the potential to generate greater carbon savings across building sector processes.

It has become evident that the weight of a material can have a significant impact on the emissions produced. This is especially the case during the transport of pre-insulated pipework to construction sites. As PP-R is up to 37% lighter than steel, it has the potential to reduce the carbon footprint of this often-overlooked operation.

REHAU’s own findings demonstrate the difference that can be made through informed material choice. Through sample project calculations, it was revealed that PE-Xa pipes can cut carbon emissions from transport by up to 67% compared to steel use. This statistic goes to show how choosing a fully polymer district heating system can also make associated undertakings more sustainable.

Building on this, polymer enables greater efficiency in installation. As a lighter material, there is reduced need for mechanical handling equipment to install underground pre-insulated pipes. With less requirement to transport and operate such apparatus for projects, fuel-intensive processes can subsequently be reduced.

Furthermore, REHAU’s polymer pipes eliminate expansion loops and reduces directional change bends used in steel counterparts. Installation is therefore quicker, which can help to speed up project completion. Less time on site results in reduced overall costs and more projects being installed. It is through these changes in processes that building professionals can take further steps to decarbonise.

The capacity to reduce carbon emissions in both construction and application highlights polymer pipe as a key solution for district heating. By making the right material choices, the construction sector can make greater progress toward Net Zero targets.

Click here to find out more about REHAU’s range of district heating solutions.