Green heat network providers

Neal Herbert of GTC discusses how heat networks are revolutionising heat and hot water delivery in new homes, playing a key role in the UK’s ongoing shift to sustainable, low-carbon developments.

The integration of renewable energy into developments is becoming a crucial consideration as the UK continues its journey to reduce reliance on fossil fuels.

Heat networks are poised to play a significant role in the nation’s path to net zero by 2050. To meet this ambitious target, those shaping current and future housing and commercial developments must have a clear understanding of the technology, design parameters, sizing, installation, and ongoing operation of these systems, which are increasingly replacing gas networks.

A clear understanding of how heat networks function both technically and in relation to end users will be key to successful implementation. It’s also important to note that various types of heat networks are available, offering flexibility based on a site’s specific requirements.

How heat networks work

Heat networks use a central plant to generate heat, which is then distributed through a network of highly insulated pipes to multiple buildings or units. The design of these pipes should consider the layout of the development, heat losses from the pipes, while ensuring the network can handle the required flow rates and temperatures for efficient heating and hot water delivery.

Design parameters

When integrating a heat network, the building layout and zoning are crucial. Buildings should be designed to allow for easy connection to the central heating plant, ensuring even and efficient heat distribution and proper routing of piping. Thoughtful zoning of heating requirements can help to reduce the load on the system.

If a central heat hub is specified, adequate space must be allocated for the plant and distribution system. The location of the heat generation plant should be carefully considered early in the planning process to ensure unobtrusiveness and effectiveness.

Each building or home must also have space for a heat interface unit, which controls the heat and hot water delivery. These units are typically installed in utility or plant rooms.

The internal heating systems should be compatible with the heat network, including considerations for radiators, underfloor heating, and other methods of heat delivery. The location of systems’ controls, such as smart thermostats, is also important to ensure users can manage their heating effectively.

For precise specification, it’s important to understand the temperature and pressure requirements of the heat network to ensure building systems – especially distribution piping and radiators – can accommodate these levels. As heat networks generally operate at lower temperatures than traditional gas heating, this may affect the selection of internal heating solutions. Prioritising high-efficiency design is key, ensuring that the heat network’s temperature aligns with the building’s specific heating needs.

Sizing the heat network

Sizing is essential to ensure the development has adequate heating capacity. Collaboration with engineers is necessary to estimate the heat demand for the entire site, factoring in building size, insulation standards, occupancy levels, and external temperature variations.

Engineers typically perform heat-load calculations to determine the capacity of the central plant, as well as the required size of pipes and heat exchangers.

Energy efficiency & sustainability

Heat networks offer an excellent opportunity to integrate renewable energy into a development. Considerations should include how renewable heat sources can be incorporated into the system to reduce reliance on fossil fuels, and ensuring the buildings are well-insulated and airtight to improve network efficiency.

Smart controls, including heat meters and interfaces for monitoring, should also be factored into the design.

Regulatory & planning considerations

Heat networks must comply with national and local building regulations, particularly those related to energy efficiency, carbon reduction, and safety. In the UK, this includes compliance with Part L (Conservation of Fuel and Power) and Part G (Sanitation and Hot Water), which govern heating system design as well as system installation.

Some local authorities may also have specific heat network requirements, so close coordination with planning authorities is essential to align with local energy strategies.

Maintenance & operational considerations

Heat network designs should facilitate easy access for maintenance and inspections, including the provision of dedicated plant rooms, service ducts, and clear pathways for equipment access.

In conclusion, when integrating heat networks into new developments, careful consideration of space planning, energy efficiency, regulatory compliance, and future scalability is critical. Working with engineers and other specialists ensures the design is efficient, sustainable, and future-proof. The building envelope and occupant comfort must always be prioritised to ensure the system operates optimally and meets both environmental and user needs.

Neal Herbert is managing director at GTC