INDUSTRIAL AND COMMERCIAL HEATING AND COOLING SPECIAL FEATURES This month: Hybrid heating; cooling at 22 Bishopsgate; fan coil innovation UNLOCKING THE POTENTIAL OF HEAT NETWORKS Figure 1: Indicative heat-zoning output undertaken on behalf of Bristol City of the city where heat networks are theoretically the lowest-cost option to achieve heat decarbonisation The rollout of heat networks are a key plank of the governments Heat and Buildings Strategy. To identify the urban areas most suitable for networks, the government has published a new document on zoning, as Andy Pearson reports O n 8 October 2021, the government published a consultation on proposals for heat network zoning in England (bit.ly/CJNov21HNZ). Heat networks transfer heat (hot water/and or cooling) from a central source or sources to buildings, including dwellings, public buildings, and business and commercial premises. As such, they are able to unlock the use of large-scale recovered waste heat from industry, rivers and mines. The heat zoning proposals envisage central and local government working with industry and local stakeholders to identify and designate areas within which heat networks are the lowest-cost low carbon solution for decarbonising heating. If adopted, certain buildings within declared zones could be mandated to connect to a heat network. The proposals are underpinned by three CIBSE documents CP1: Heat networks: Code of practice for the UK (2020); Design guide: Heat networks; and Guidance note: Domestic hot-water temperatures from instantaneous HIUs. A lot of things are coming together on the heat networks front, says Phil Jones, an independent energy consultant. The consultation is the governments first step in addressing barriers to the implementation of heat networks in England. It says there is significant potential for the number and scale of networks to increase dramatically by central and local government working together with industry to designate areas in which networks can be deployed as a low-cost solution for decarbonising heating. Heat networks are sometimes characterised by high upfront capital costs with long payback periods. In addition, the risk of heat loads not connecting to networks can create uncertainty, which government says hampers investment. Zoning is intended to tackle this by providing investors with connection assurance, because it will be mandatory for key buildings to connect to networks, as long as it is costeffective (and practical) to do so. To ensure an established customer base for heat, all new buildings, large public sector and large non-domestic buildings, and communally heated domestic premises would be required to connect to a heat network within a prescribed timeframe. Jones says its about providing a demand so that a heat network operator can be certain that at least the mandated buildings will connect, leading to a viable project. Developing a heat network also requires coordination and agreement between the developer and a range of parties, which can be challenging and deter investors. Zoning tackles this by taking a central strategic approach to heat decarbonisation and giving the government the www.cibsejournal.com November 2021 39 CIBSE Nov21 pp39-41 Heat networks guidance.indd 39 22/10/2021 16:25