Research And Insight

A new way to deliver a chilled water system

Grundfos Distributed Pumping will change the way you deliver chilled water systems. The innovation at the heart of this is the move towards decentralised pumping. Under this system, a network of smaller pumps can respond more quickly the needs of your users, creating optimal building comfort and maximizing energy efficiency.

This new pumping principle is as flexible as it is efficient, meaning that it’s ready to meet the growing demand for cooling by taking building comfort and efficiency to new levels.

The global cooling demand has doubled in less than 20 years

Global use of energy is projected to increase almost 25% by 2050. In the past 20 years alone, the global cooling demand alone has nearly doubled, making it critical to rethink chilled water systems and improve energy efficiency.

Distributed Pumping has the potential to save up to 54% energy

Many buildings operate with centralised and inefficient chilled water systems. Replacing balancing and control valves with distributed pumps can reduce total pump energy consumption for a chilled water loop by 54%, amounting to substantial energy savings.

Around 45% of chilled water pumps run at peak-load most of the time

It’s estimated that 45% of pumps within chilled water systems are running constantly at peak load. Yet this level is rarely needed since chilled water systems only operate at peak consumption a very small fraction of the time – roughly 1-3%.

Many buildings are running inefficient chilled water systems. There is often one, large pump running at peak load and research shows that they are often over-pressurized and have low Delta T.

This often happens because the chilled water system was badly commissioned or hastily designed, even before it started to operate. It can also happen because the building it services has changed purpose or design since it was built. No matter what the reason, an inefficient chilled water system can cause high energy bills and unhappy occupants.

In this video, you can learn more about why a chilled water system might run inefficiently - and how Grundfos Distributed Pumping can minimize energy consumption while maximizing indoor comfort.

The typical challenges

When it comes to chilled water systems, many buildings are still working with inefficient, decades old solutions. As a result, these chilled water systems will typically experience a number of challenges, such as poor pump control, low Delta T and difficulty complying with building energy codes, as well as complexities in design, installation and commissioning.

Inefficiency occurs when a chilled water pump sized for full system flow and maximum pressure loss operates at too high a speed. This results in over-pressurisation and low Delta T. Control and balancing valves have to throttle the flow and pressure. This is like controlling the speed of a car with a handbrake.

Inadequate commissioning and poor chilled water pump control also lead to imbalanced systems and excessive energy use. And it’s not only energy waste that’s the problem; indoor comfort for occupants is also compromised. On top of this, there’s the risk of legal penalties if energy consumption requirements aren’t fully complied with.

How you can optimise

When optimizing energy efficiency in buildings, the focus is often on energy creating systems such as boilers and chillers. However, as energy distribution has a significant impact on overall energy consumption, an increased focus towards energy distribution is necessary.

A system can utilise intelligent pumps on each floor of a building to achieve this optimal energy distribution – eliminating the need for valves in the building since the pressure is provided only when and where it’s needed.

Replacing valves with pumps will ensure optimal pressure and flow to each terminal unit at all times. This kind of demand-driven system enables easy commissioning, an automatically balanced system throughout a building’s lifetime, improved Delta T, seamless integration and minimum pump pressure. All of which means significantly reduced energy use.

The solution

Grundfos iSOLUTIONS offers a new pumping principle for chilled water systems called Distributed Pumping. It requires no control-, balancing- or PICV valves since these are replaced by smaller intelligent pumps such as the Grundfos MAGNA3. The overall pressure in the system is therefore significantly lower as each pump generates only the amount of pressure needed.

In addition to this, the large primary pump is exchanged with a smaller, intelligent pump such as the Grundfos TPE3, enabling significant CAPEX savings. These intelligent pumps are connected to sensors so that operation adjusts to the demand. And this system design results in substantially lower energy usage and total expenditures.

Ultimately, Grundfos Distributed Pumping is the most efficient way of circulating chilled water in HVAC systems today. It’s able to take building comfort and efficiency to new levels, saving OPEX, commissioning time and energy. So, with Grundfos Distributed Pumping for commercial buildings, you can fully control a chilled water system, minimise energy and costs, and ensure a much more comfortable indoor climate.

Explore Distributed Pumping solutions

Grundfos Distributed Pumping makes it easy to balance chilled water systems and to use them to enhance comfort in buildings. The solution replaces traditional balance and control valves with intelligent pumps.

Grundfos Distributed Pumping helped Ngee Ann, a large university building in Singapore, increase Delta T by 28% and reduce total pump energy by 54% – all while providing optimal comfort for building users.

Read the case

SOURCES

Source¹: Global cooling report; International Energy Agency, June 2020

Source²: Grundfos Case Ngee Ann Polytechnic (Polytechnic Block 22), energy savings calculation of Distributed Pumping compared to conventional system

Source³: Seasonal load changes, when calculating Energy Efficiency Ratio EER and Integrated Part Load Value IPLV for chilled water systems