iGRID Temperature Zone

A district heating grid is typically designed for the customers with the highest requirements of temperatures and pressures, causing a large number of disadvantages in other parts of the grid.

With Grundfos iGRID Temperature Zone, you can divide the city into smaller zones where demands are lower and thereby reduce heat losses significantly, lower the carbon footprint and increase the grid capacity.

By dividing your city into smaller zones, you can, in a decentralised way, reduce your heat losses significantly and with a very short return on investment.

Watch the iGRID Temperature Zone film and see how it works.

Demand-driven temperature optimisation

The iGRID Temperature Zone is an intelligent mixing loop, ideally connected to Grundfos iGRID Measure Points for demand driven temperature optimisation based on real-time data from strategic points in the grid. 

Additionally, it can be installed with the iGRID Temperature Optimiser for optimal temperature control based on peak shaving algorithms, weather compensation and real-time data from iGRID Pit Measure Points. 

Reducing temperatures results in significantly reduced heat losses, leading to lower carbon emissions, increased capacity in the grid and an increase of asset lifetime of e.g. pipes and consumer installations.

With these zones, you can even increase pressure where needed to reduce residual pressure in the grid.

Short return on investment

In most heating grids, several parameters lead you to operate differently than originally designed:

• The design is based on the customers requiring the highest temperature and pressure.

Installations are typically at least 20 % oversized 

• Energy renovation has been carried out – e.g. new windows, more insulation etc.

• The design peak loads are only reached a few minutes per year

• New and renovated buildings have much lower heat demands

This makes it possible to identify many smaller city zones where temperatures can be significantly reduced, leading to the short returns on investment.

The basic variants of the iGRID Temperature Zone

The iGRID Temperature Zone comes in three fundamental variants of mixing loops to meet different needs. All solutions ensure that the colder return water from the zone is mixed with the hot water from the supply line to reach the needed temperature in the zone – nothing more and nothing less.

The free solution

An efficient solution whereby pressure can be increased in the zone. By the use of a pump in the bypass, the pressure from the supply is adjusted in order to add the required return of water. Consequently, a free flow of water is created and a traditional motor valve is no longer necessary. Nonetheless, the need for maintenance is reduced due to a high degree of reliability.

This is the ideal solution for reducing heat losses to a minimum.

The shunt solution

A cost-effective solution utilising pressure from the main pumps in the existing grid. A pump in the bypass is designed to overcome pressure from the supply to add the needed flow of return water.

This solution is suggested if there is always enough supply pressure for the zone and no ambition to implement the low pressure benefits of distributed pumping.

The pressure reduction solution

A shunt solution with a pressure control valve utilised when the pressure in the zone is higher than required.

This will reduce the pumping need for mixing and pressure reduction in all buildings will no longer be required. Additionally, it will increase the lifetime of pipes and building installations.


Water loss

Globally an average of 30% of all pumped water never reaches the tap. In cities the average is even higher and can reach 60%. This water is lost due to both leakages and theft. A few examples of non-revenue water (NRW) per country are: United Kingdom 21%, Mexico 40%, United States 20%, Sweden 40%, Liberia 49%, Armenia 89%, China 21% and Venezuela 62%.

Source: Quantifying the global non-revenue water problem, R. Liemberger and A. Wyatt

Water demand

Today, more than 2 billion people are living with the risk of reduced access to freshwater sources. By 2050 the global water demand could be 30% higher than it is today. 

Sources: United Nations Sustainable Development Goal 6, UNWD Report 2018


By 2050, an additional 2.5 billion people are expected to live in cities, which accounts for 70% of the population. 90% of this increase is expected to take place in Africa and Asia.

Source: United Nations Department of Economic and Social Affairs

Solutions in action

Although cities around the world are under a lot of pressure, there are intelligent solutions available for better, more efficient, more sustainable water management. Some of these solutions are already in action, like water treatment, water reuse and demand-driven distribution which is ensuring optimal water pressure and flow and minimising pipe bursts for towns and cities all over the globe.

Ningbo doses safely and accurately for 1.5 million citizens

10 years ago, a lake water plant in the Chinese city of Ningbo needed help pumping the dangerous compound sodium hypochlorite. Today, the Grundfos dosing pumps implemented are still going strong and guaranteeing safe water for 1.5 million citizens. 

Water plant enjoys 20% energy + water savings 

In the Cambodian province of Takéo, a water supply company was struggling to supply drinking water to the small city of Doun Kaev and the surrounding 45 villages. After teaming up with Grundfos, an intelligent demand driven water supply solution solved the problem and cut water losses by 13% and pipe bursts by 29% giving villagers reliable water supply 24/7.

Pump gates bring new flow to Fuzhou’s rivers

Fuzhou, a large city in China, has had problems with dirty, odorous water in its rivers and canals for decades. A series of Grundfos pump gates brought flow once again to the water. This solution eradicated the smelly, polluted water, creating a better living environment along the populated riversides.

Want to learn more?

In order to make a positive change, we must act now. Visit the links below for further learning, including exploring current solutions for buildings as well as Grundfos intelligent pump solutions. 

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