Balancing a chilled water system

Everyday life involves the use of cooling systems for buildings, industrial applications etc. to keep comfort at an optimum level. From the various cooling solutions available, one and very common is the chilled water system. The electrical energy consumption of such system might constitute up to 35-60% of a building’s total energy consumption. Hence, energy optimization becomes a very important topic.

Grundfos offers a Cooling as a Service solution (CaaS) for optimizing and balancing your chiller plant to deliver the demanded cooling with the lowest energy consumption. This is done by an automated solution which monitors and improves the interaction between the various parts of your plant’s HVAC system as explained step-by-step below.

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Water balancing

One of the most important factors in a chiller plant system is water balancing. If the water flow is not sufficient e.g. in the air handling units or in the evaporator of the chiller, the heat transfer can be greatly reduced which causes the coils not to absorb the required heat. The side effect is an increased energy consumption, as the chiller will not be operated according to rated conditions which are causing poor efficiency. It can also be the case that the water flows are much higher than rated, which will lead to energy waste as the chilled and condensed water pumps are operating at a higher frequency than required. To ensure correct water balancing, Grundfos CaaS uses flow meters and frequency drives as an add-on to your chiller plant to correct flow balancing at all loads.

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Temperature control

What if the cooling demand could be fulfilled by less compressor work? Often the chilled water forward and return temperatures can be increased while still maintaining the same comfort level. In general, the efficiency can be increased by 2% for every degree the chilled water supply temperature is increased. This can be done by implementing temperature control and flow control which are used by Grundfos CaaS, to find the sweet spot of the chiller in a combination of temperature, flow, and energy consumption.

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Outdoor climate control

When the outdoor temperature and humidity are changing, the dew point temperature will either increase or decrease. Grundfos CaaS uses outdoor temperature and humidity sensors as well frequency drives to ensure the cooling tower fans are not operated at higher speed than needed to dissipate the heat from the condenser. This helps to decrease the energy consumption by lowering the fan speed.

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Electrical energy meters

For continuous monitoring of the entire chiller plant efficiency, measured in kW/RT, Grundfos CaaS utilizes electrical energy meters to monitor how much energy is being consumed to deliver the required refrigerant ton. In combination with Grundfos CaaS automated control system, it is possible to always adjust, control and measure that the chiller plant is delivering the demanded cooling at the lowest cost.

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Condition monitoring

Imagine that your condenser pumps are failing and are causing your chiller plant to shut down! This would be a worst-case scenario causing customers and guests to escape your building or standstill of your production. No worries, Grundfos CaaS includes condition monitoring which can predict coming failures in your chiller plant, giving you enough time to get the faulty components changed before failure.

If you want to find out your potential energy savings and how Grundfos CaaS can help you lower your energy costs and save CO2, you can try out our free saving calculator here:

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Energy saving calculator