HOW TO OPTIMISE THE SUCCESS OF A HEAT NETWORK
Heat networks are increasingly seen as important technology to enable the UK to meet net zero targets. So, what should planners and consultants consider when it comes to ensuring the pipework can optimise the energy efficiency of a heat network? Here, we talk to our Business Development Manager Rob Oakley, who answers some of the key questions specifiers are asking.
This does really depend on the nature of the project, and there are different products that are manufactured to meet the differing needs of specific applications. However, broadly speaking, there are several overarching considerations to take into account:
The CIBSE CP1 Code of Practice for Heat Networks (2020) provides the minimum standards to ensure that any heat network meets the necessary energy performance targets. Whilst not a legal requirement, this Code of Practice is widely regarded as the benchmark for regulation. For example, the Department for Business, Energy and Industrial Strategy (BEIS) has indicated an intention to legislate on the principles of CP1.
Thermal performance
Whatever the scale of the project, the thermal performance of the pipework is key to the success of the heat network system. The CIBSE CP1 Code of Practice outlines the minimum thermal insulation thicknesses for different pipe diameters.
To meet the requirements of CIBSE CP1, the pipework insulation should be considered during the early stages of each project and further calculations for heat losses should be implemented at the stage two feasibility stage, as well as at the design stage (Stage 3).
Flow rate and pipe size
The rate at the fluid flowing inside the pipe also another element that plays a critical role in how efficient and effective the heat transfer is across a network. Any adjustment to the flow rates – which is proportional to the diameter of the pipe – can lead to significant differences in heat output. For example, a larger diameter pipe will allow for a significantly higher flow rate. Similarly, heat losses are proportional to pipe diameter.
Reducing the system flow rates saves pump energy (and costs), increases system Delta-the chances of the network overheating. Minimising the size of the pipe will also reduce its surface area – and in turn, the potential for heat loss. However, undersized piping could limit or prevent the possibility of future expansion opportunities.
The CIBSE CP1 Code of Practice does provide some guidance on a velocity-based pipe sizing approach to help support this element of specification, but as you can see, there is a clear balance to be found between network pressure, heat loss as well as the overall capital cost. Choosing a supplier that can provide advice on this and engaging early is vital to determine the best solution.
Installation
An obvious one, but the installation time will impact upon the critical path, scheduling and costs of the project. As such, it’s important to consider products that can save time and labour costs.
Maintenance
Ultimately, investors, developers, landlords and end clients want their heat network scheme to be low maintenance – without additional costs. Choosing a reliable and durable system that can offer this reassurance should be a key part of the initial design, planning and specification stage.
We have a comprehensive range of pre-insulated pipes within our Uponor Ecoflex collection. The thermal insulation properties of this make it an ideal specification for heat networks, as well as for single use heat pump installations. The range comprises a vast choice of sizes and formats for different applications as well as jointing options and accessories and has been used all over the world on large projects. Click here to read more.
Within the Uponor range there are three distinct Ecoflex product lines that have been designed for different services:
Within each category there a several product variations. For example, Ecoflex VIP – our flagship product with the highest insulation values, is available within the Uponor Thermo and Aqua ranges. Click here to discover more detail about the Ecoflex range and Ecoflex VIP. And the Uponor Ecoflex Thermo Twin HP, designed for heat pumps include flow and return pipe alongside conduits for electrical and sensor cabling in a single packaged pipe.
Thermal performance
Ecoflex has been engineered to offer superior insulation performance. I think this is the key benefit that it offers a revolutionary low lambda value insulation material that complements the CIBSE CP1 Code of Practice at <0.004 W/mK. This performance is 10 times better than soft foam insulation and 5 times better than hard foam insulation.
It is manufactured with a combination of cross-linked microcellular polyethylene (PE-Xa) foam, or highly effective PUR foam, an advanced EVOH oxygen barrier and a water repellent closed cell structure providing specifiers with the reassurance that the pipe will maintain a consistent temperature, regardless of the length.
Installation
As Ecoflex can be bent rather than cut to achieve changes in direction, it requires fewer joints and fittings. In fact, the bending radius of Ecoflex enables the pipe to manoeuvre around tightly branched networks and existing features such as trees, or buildings, which reduces the need to create joints – and this also means less inspection pits. This flexibility can reduce the installation time of the pipes by up to 20% compared to hard foam insulated flexible pipes, and by more than double compared to steel pipes.
Furthermore, the outer diameter of Ecoflex Thermo VIP is up to 30% smaller than alternatives on the market. This means that the trenches can be narrower – again, saving time and labour costs.
Ecoflex also does not require specialist trades for installation and is supplied with connection ends in place, so the pipe is ready for connection straight away.
Reliability and maintenance
As Ecoflex can be installed as one continuous pipe, there are less joints that pose risk to the system. Furthermore, plastic piping is corrosion resistant, so the lifetime of the product is extended providing peace of mind for clients. This also means the formation of biofilms, sludge and debris is far less likely to occur than in copper systems.
The high-density polyethylene (PE-HD) jacket used on the Uponor Ecoflex range is tested to ISO 9969:2016 standards for a static strength of 60 tonnes, making this a robust choice.
Uponor Ecoflex pre-insulated pipes are manufactured according to European Standard EN15632 under quality management system certification according to ISO 9001 and 14001 standards.
Our Ecoflex pipe is backed with a market leading 25-year warranty and a 50 year+ design life. Notably, with Ecoflex, the warranty is automatically applied – there is no paperwork or admin involved for the customer.
Unlike steel or copper, Ecoflex can be supplied in one continuous coiled length which can be cut to size prior to its delivery to site, if desired. Lengths do depend on each product within the ranges, but Ecoflex can be supplied up to 240 metres (or cut to a desired shorter length to reduce waste and costs).
There are two principle delivery routes for planners to choose from:
We know the value of a collaborative, consultative approach to projects such as these and can provide tailored assistance at every stage. This includes design and estimating for take offs, provision of technical guides and specification data, full, free training on installation, on site installation support, as well as ongoing installation quality reviews to check that the products are being installed in line with best practice. This helps to improve quality control and consistency to minimise the risk of issues as the project progresses.
Something we really pride ourselves on is that our support services are at no additional cost. We have over 100 years of experience and we apply this knowledge to every product and project we work on. For us, we believe it is imperative to provide our customers with value added services throughout a project lifecycle. Click here to access our online library of resources.
We always recommend engaging early on, so that we can discuss the project in full. This will allow design recommendations to be implemented more easily and cost effectively with less wasted time.
To speak to one of team about your heat network scheme, contact us today by email: customersupport.uk@uponor.com, or call: +44 (0)1923 381212.
Uponor is a member of key industry body, the UK District Energy Association (UKDEA) where we collaborate in sharing best in class technology and manufacturing standards to help drive best practice in the delivery of heat network schemes across the UK. Read our interview with Simon Woodward, Chairman of the UK District Energy Association (UKDEA) on the future outlook for heat networks in the UK.
What do you think are the key factors specifiers should consider when choosing insulated pipe for a heat network?
This does really depend on the nature of the project, and there are different products that are manufactured to meet the differing needs of specific applications. However, broadly speaking, there are several overarching considerations to take into account:
- Compliance
- Thermal performance
- Flow rate
- Installation
- Maintenance
The CIBSE CP1 Code of Practice for Heat Networks (2020) provides the minimum standards to ensure that any heat network meets the necessary energy performance targets. Whilst not a legal requirement, this Code of Practice is widely regarded as the benchmark for regulation. For example, the Department for Business, Energy and Industrial Strategy (BEIS) has indicated an intention to legislate on the principles of CP1.
Thermal performance
Whatever the scale of the project, the thermal performance of the pipework is key to the success of the heat network system. The CIBSE CP1 Code of Practice outlines the minimum thermal insulation thicknesses for different pipe diameters.
To meet the requirements of CIBSE CP1, the pipework insulation should be considered during the early stages of each project and further calculations for heat losses should be implemented at the stage two feasibility stage, as well as at the design stage (Stage 3).
Flow rate and pipe size
The rate at the fluid flowing inside the pipe also another element that plays a critical role in how efficient and effective the heat transfer is across a network. Any adjustment to the flow rates – which is proportional to the diameter of the pipe – can lead to significant differences in heat output. For example, a larger diameter pipe will allow for a significantly higher flow rate. Similarly, heat losses are proportional to pipe diameter.
Reducing the system flow rates saves pump energy (and costs), increases system Delta-the chances of the network overheating. Minimising the size of the pipe will also reduce its surface area – and in turn, the potential for heat loss. However, undersized piping could limit or prevent the possibility of future expansion opportunities.
The CIBSE CP1 Code of Practice does provide some guidance on a velocity-based pipe sizing approach to help support this element of specification, but as you can see, there is a clear balance to be found between network pressure, heat loss as well as the overall capital cost. Choosing a supplier that can provide advice on this and engaging early is vital to determine the best solution.
Installation
An obvious one, but the installation time will impact upon the critical path, scheduling and costs of the project. As such, it’s important to consider products that can save time and labour costs.
Maintenance
Ultimately, investors, developers, landlords and end clients want their heat network scheme to be low maintenance – without additional costs. Choosing a reliable and durable system that can offer this reassurance should be a key part of the initial design, planning and specification stage.
With this in mind, which insulated pipe is best suited for use in a heat network scheme?
We have a comprehensive range of pre-insulated pipes within our Uponor Ecoflex collection. The thermal insulation properties of this make it an ideal specification for heat networks, as well as for single use heat pump installations. The range comprises a vast choice of sizes and formats for different applications as well as jointing options and accessories and has been used all over the world on large projects. Click here to read more.
Talk us through the range, what are the available options?
Within the Uponor range there are three distinct Ecoflex product lines that have been designed for different services:
- Ecoflex Thermo for heating and cooling
- Ecoflex Aqua for warm tap water
- Ecoflex Supra for cold water or mains pipework only
Within each category there a several product variations. For example, Ecoflex VIP – our flagship product with the highest insulation values, is available within the Uponor Thermo and Aqua ranges. Click here to discover more detail about the Ecoflex range and Ecoflex VIP. And the Uponor Ecoflex Thermo Twin HP, designed for heat pumps include flow and return pipe alongside conduits for electrical and sensor cabling in a single packaged pipe.
Can you talk us through the key features and benefits of Ecoflex?
Thermal performance
Ecoflex has been engineered to offer superior insulation performance. I think this is the key benefit that it offers a revolutionary low lambda value insulation material that complements the CIBSE CP1 Code of Practice at <0.004 W/mK. This performance is 10 times better than soft foam insulation and 5 times better than hard foam insulation.
It is manufactured with a combination of cross-linked microcellular polyethylene (PE-Xa) foam, or highly effective PUR foam, an advanced EVOH oxygen barrier and a water repellent closed cell structure providing specifiers with the reassurance that the pipe will maintain a consistent temperature, regardless of the length.
Installation
As Ecoflex can be bent rather than cut to achieve changes in direction, it requires fewer joints and fittings. In fact, the bending radius of Ecoflex enables the pipe to manoeuvre around tightly branched networks and existing features such as trees, or buildings, which reduces the need to create joints – and this also means less inspection pits. This flexibility can reduce the installation time of the pipes by up to 20% compared to hard foam insulated flexible pipes, and by more than double compared to steel pipes.
Furthermore, the outer diameter of Ecoflex Thermo VIP is up to 30% smaller than alternatives on the market. This means that the trenches can be narrower – again, saving time and labour costs.
Ecoflex also does not require specialist trades for installation and is supplied with connection ends in place, so the pipe is ready for connection straight away.
Reliability and maintenance
As Ecoflex can be installed as one continuous pipe, there are less joints that pose risk to the system. Furthermore, plastic piping is corrosion resistant, so the lifetime of the product is extended providing peace of mind for clients. This also means the formation of biofilms, sludge and debris is far less likely to occur than in copper systems.
The high-density polyethylene (PE-HD) jacket used on the Uponor Ecoflex range is tested to ISO 9969:2016 standards for a static strength of 60 tonnes, making this a robust choice.
With durability and performance being key issue for specifiers - does Ecoflex have a guarantee?
Uponor Ecoflex pre-insulated pipes are manufactured according to European Standard EN15632 under quality management system certification according to ISO 9001 and 14001 standards.
Our Ecoflex pipe is backed with a market leading 25-year warranty and a 50 year+ design life. Notably, with Ecoflex, the warranty is automatically applied – there is no paperwork or admin involved for the customer.
On the practical side, how can the product be sized and delivered?
Unlike steel or copper, Ecoflex can be supplied in one continuous coiled length which can be cut to size prior to its delivery to site, if desired. Lengths do depend on each product within the ranges, but Ecoflex can be supplied up to 240 metres (or cut to a desired shorter length to reduce waste and costs).
There are two principle delivery routes for planners to choose from:
- We can deliver the product directly to site. This can be pre-cut to the required length and/or scheduled to fit with project timelines, so the product is ready to install as soon as it comes off the lorry.
- We can arrange for the product to be delivered via our distribution partners. Again, this can be pre-cut and/or, timed in line with project schedules.
Do you offer additional services to specifiers wanting to use this on product on their next project?
We know the value of a collaborative, consultative approach to projects such as these and can provide tailored assistance at every stage. This includes design and estimating for take offs, provision of technical guides and specification data, full, free training on installation, on site installation support, as well as ongoing installation quality reviews to check that the products are being installed in line with best practice. This helps to improve quality control and consistency to minimise the risk of issues as the project progresses.
Something we really pride ourselves on is that our support services are at no additional cost. We have over 100 years of experience and we apply this knowledge to every product and project we work on. For us, we believe it is imperative to provide our customers with value added services throughout a project lifecycle. Click here to access our online library of resources.
We always recommend engaging early on, so that we can discuss the project in full. This will allow design recommendations to be implemented more easily and cost effectively with less wasted time.
To speak to one of team about your heat network scheme, contact us today by email: customersupport.uk@uponor.com, or call: +44 (0)1923 381212.
Uponor is a member of key industry body, the UK District Energy Association (UKDEA) where we collaborate in sharing best in class technology and manufacturing standards to help drive best practice in the delivery of heat network schemes across the UK. Read our interview with Simon Woodward, Chairman of the UK District Energy Association (UKDEA) on the future outlook for heat networks in the UK.