Flexible heat pump systems for high-efficiency heat networks

Heat networks, combined with the latest heat pump technology, are key to cutting carbon emissions according to the government’s Heat and Buildings Strategy. Stimulation for this approach is being provided by the Green Heat Network Fund (GHNF) which was launched in March.

The GHNF is a three-year, £288m capital grant fund, which opened to applicants in March 2022 – a core element of the Government’s Heat Network Transformation Programme (HNTP). At present, it is estimated that around 2% of the UK heat demand is delivered through heat networks, with ambitions to reach 18% by 2050.

It is hoped that through the provision of targeted commercialisation and construction funding, the GHNF will help tackle some of the barriers to this mass approach to low carbon heating. In the coming years officials plan to identify heat network zones through a mapping exercise, where viable locations around the country will be earmarked.

Beating fuel poverty

Apart from reducing carbon, heat networks have a key role to play in beating fuel poverty. Electric storage heaters still form a large proportion of heating provision in social housing; an expensive and inefficient solution that continues to be installed, despite its unsuitability. Heat networks are an ideal alternative, allowing housing associations to dramatically reduce costs for their tenants – often by as much as two-thirds.

When compared with fossil fuel heating, until recently, heat pumps were more expensive to run, however that has now changed. A recent study by energy contract provider, Verivox, revealed that heating expenditure with a heat pump is around 39% lower than in applications using natural gas. Even with a less efficient heat pump, costs are around 11% lower, says the company.

Additionally, it is likely that the levies currently placed on electricity will move over to gas, making ‘the electrification of heat’ an even more appealing prospect. Compared with gas or oil boilers, heat pumps generally last longer, providing further savings in whole-life costings, helping to counter the cost of initial investment, which is higher than ‘quick fix’ storage heaters.

The heat pump solution

Heat pumps are particularly well-suited to this type of heating provision as they are modular, so district heating schemes can be designed to heat any number of properties of all sizes – from flats to detached houses.

Heat pump systems can also run in tandem in multiple bases and plant rooms to provide heating and hot water for an almost limitless number of buildings.

When it comes to maintenance, having a central plant makes things a lot easier; particularly in tenanted homes. Servicing and repairs can be carried out without entering properties. Overall, maintenance is very straightforward as there is no combustion element with no need to clean or replace components. Monitoring of operational efficiency and adjustments can often be carried out remotely.

The latest heat pump technology

The latest heat pump technology offers ultra-high efficiencies, with high or low temperature options that fit seamlessly into heat networks of either the district or communal variety. The manufacturing industry, for example, often requires low temperature processing, whereas hospitals and hotels need water at temperatures not usually associated with heat pumps; recent technological developments mean that there are now a number of high temperature solutions, offering water up to 90°C. Cooling is also a consideration, particularly in urban areas and communal workspaces. Many commercial heat pumps can do both.

In heat pumps where refrigerant is required – common in larger scale schemes – choosing an option that can utilise refrigerants with a lower Global Warming Potential (GWP), will enhance environmental benefits and ensure future-proofing. CO2 is one such alternative.

The ability to monitor and operate the heat pump remotely is also key – to prevent downtime and minimise the need for site visits. Smart operation, touch panels on the plant itself and remote access via any internet enabled device, make off-site automation far more viable.

Meeting the demands of modern living

There are two types of heat networks: district heating and communal heating.

A communal network supplies heating and hot water to a number of customers within one building – the most likely option for commercial buildings. The district version consists of a local energy centres supplying heating and hot water to multiple properties (domestic dwellings, for example).

At the moment, according to market data collected by the government, 85% of the heat networks are of the communal variety. In the future this balance needs to shift to a more equal footing – heat networks have great potential in the UK’s cities, where individual renewable applications may not be viable.

Let’s not forget that heat pumps can also provide cooling, helping built-up environments adapt to climate change, while contributing to halting the ongoing grip of global warming.

Engie Spectrum Water

The pioneering Engie Refrigeration Spectrum Water supplied by Klima-Therm, is an ultra-high efficiency heat pump designed for industrial and commercial applications or integration into heat networks and district heating in housing developments.

The 12 models in the series boast nominal heat outputs of 350 to 3,100kW, a condenser leaving water temperature of up to 65 deg C, and the choice of four refrigerants – R1234ze, R515B, R513A, and R134a.

Engie Spectrum boasts outstanding energy efficiency, superb operational reliability, and the highest possible quality thanks to a combination of innovative components including oil-free turbo compressors with magnetic bearings, an efficiency-boosting open-flash economiser, and an intelligent Siemens S7 PLC.

Find out more about our full range of heat pumps.