Hot Water Energy Calculator

Please accept all cookies to view the youtube video content.

How does the tool work?

GF Piping Systems, together with scientists from the Ostfalia University of Applied Sciences, has developed an online calculator that can be used to easily and quickly calculate the amount of energy needed to provide hot water in buildings. 

How can such a complex calculation be done so easily?

The easy-to-use online "Hot Water Energy Calculator" is the result of extensive development work by GF Piping Systems and the Ostfalia University of Applied Sciences. The calculations are based on the currently valid DIN standards and further assumptions, which are shown. A first reference project, during which the results were simulated before optimization, demonstrates that the results of the calculations are realistic. The data evaluation is being continuously refined and verified on real buildings. The tool provides valuable input for deciding when the investment to optimize a hot water system in a building will start to pay off.

How can energy consumption for hot water be reduced?

In principle, three technical measures can be employed to cut energy consumption for producing hot water – apart from reducing hot water consumption itself:

  • repairing the insulation around the hot water pipes and fittings
  • setting the optimum operating point of the hot water circulation with the Hycleen Automation System and its electronic balancing valves
  • modernizing the installation technology: the efficiency of hot water production and of the circulation pump usually depends on the age of the technology involved. Essentially, the newer the technology, the higher the efficiency.

It should be noted that drinking water hygiene is fundamentally more important than saving energy.

What does hydraulic balancing do?

Faultless hydraulic balancing reduces the amount of circulating hot water. Lower system temperatures are made possible by reducing the thermal losses. The poorer the hydraulic balancing and the greater the thermal losses, the higher the amount of energy needed to maintain the temperatures essential to impeccable drinking water hygiene. The required pump capacity is also correspondingly higher. In addition, the increased temperatures result in a larger DeltaT to the ambient temperature, which in turn increases the cooling losses in the circulation system and storage tank.

What can the Hycleen Automation System achieve?

The Hycleen Automation System ensures the optimum operating point is set by continuously monitoring the installation's condition. Consequently, a smaller quantity of hot water circulates at lower temperatures, maintaining the specified hygiene standards of course. Unnecessarily high temperatures and flow rates caused by a non-existent, poorly adjusted or unmaintained hydraulic balancing system are a thing of the past. Piping sections that suffer high thermal losses can be identified and upgraded to improve energy efficiency by repairing deficient insulation.

Proven success

Energy consumption was effectively cut by up to 25% compared to a conventional drinking water system by using mechanical balancing valves. Read the Reference report on the energy efficiency upgrade of the hot water system for 100 apartments. 

Hycleen Automation System

Hycleen Automation System Hycleen Automation System

The Hycleen Automation System from GF Piping Systems makes it easier to meet drinking water hygiene standards in large-scale buildings and reduces energy consumption for producing hot water. It ensures stable water temperatures, flushes the pipes, maintains the circulation valves, and logs all data. Water temperatures can be lowered without increasing the risk of legionella.

The system is easy to install and commission. Electronic valves with sensors and controllers are connected to the central control unit, the master, via just one cable for suppling power and transmitting data. The master monitors the sensors, reports any abnormalities and controls the system. It can also be operated from any location using an app and integrated into the building management system.


Georg Fischer Piping Systems (Switzerland) Ltd. - GF International

Amsler-Laffon-Strasse 9

8200 Schaffhausen


GF logo on the headquarters building