Solutions for homeowners

Yes, you can save a lot with hydronic balancing of the radiators. Hydronic balancing is enabling the optimal use of heated water. With hydronic balancing you don’t only save costs, but also do a step further towards smarter use of energy and energy efficiency. Heating and cooling of our buildings account for 40% of energy consumption in EU and is responsible for 36% of CO2 emissions [Source European Commission]. Therefore, with hydronic balancing you also actively participate in reduction of CO2 emissions.

Although water balancing should be a standard procedure anyway for the system to work properly, it is now also perceived as an energy-saving measure. A balanced system reduces heat loss through pipes and boosts the efficiency of boilers and heat pumps. After hydronic balancing, heat loss for household heating is generally reduced by between 12% and 20%. For this reason, water balancing has been required by law for new build and renovation projects since March 2020. 

The water flow through each radiator must be individually adjusted. Large radiators require water to flow faster than small radiators. For water balancing to take place, the number of litres that should flow through a radiator per hour is carefully determined. 

The water flow can be adjusted on a radiator valve in the radiator supply connection that can be pre-set, or by using a foot valve in the radiator return connection. Dynamic balancing is preferred. This can be done using a radiator valve with a built-in differential pressure controller such as the Danfoss RA-DV Dynamic Valve™. Dynamic balancing is the most energy-efficient balancing method, because the set water flows are maintained even with varying pressure differences in the central heating system. 

Properly functioning heating system does not leave space for any over or under-heated rooms, which could result in compromised comfort and excessive heating costs. Accurately balanced heating system ensures minimal energy consumption and secures that water flow in the radiator is stable, consequently no noise or hissing sound from radiator appears.

The easiest way to identify an unbalanced system is to switch on all radiators in the home and measure the supply and return temperatures on all radiators. If the difference between the supply and return temperature is less than 20% to 25%, you can assume that the system has not been balanced. 

For example, if you heat the system to a supply temperature of 80 degrees and the return temperature at a number of radiators is 65 or higher, the water flow through the radiators is too high, meaning the heated water will not be able to heat rooms adequately.

Yes. All radiators should be balanced to ensure the central heating system is energy efficient and does not encounter any problems. The reason for this is that even a single unbalanced radiator can have a significant impact on how the system works as a whole, especially if this radiator is located close to the boiler. In practice, unbalanced radiators have 4 to 5 times higher water flows than necessary. If a radiator is never used, leaving it out will not have a negative effect on the balancing process.

No, hydronic balancing requires special knowledge. A boiler has a huge power output of at least 22,000 watts. If the volume and speed at which water circulates in the system is inadequate, this can result in faults, a shortened service life and even increased energy consumption. 
The volume of water in the system and circulation speed must be sufficient for the boiler to run continuously for at least 10 minutes. The required water volume and circulation can usually be assured if 2 or 3 radiators are always on in the living room/kitchen. If this is not possible, an AVDO bypass and/or a buffer tank can be installed, if appropriate.

Yes, hydronic balancing is also important if you opt for a heat pump. Originally, the intended purpose of hydronic balancing was to ensure the trouble-free functioning of the system. Given the current high energy prices, energy-efficient operation is of even greater importance. In fact, hydronic balancing is legally required when installing a heat pump. The efficiency of heat pumps depends to a large extent on how high the water temperature is. The higher the required water temperature, the lower the heat pump’s efficiency. With a well-balanced system, the same or even enhanced levels of comfort can be achieved at a lower water temperature. 

Installers often choose to change existing radiator valves for radiator valves with built-in differential pressure controllers. Known as dynamic radiator valves, they can be precisely adjusted to the required water flow. Dynamic radiator valves automatically maintain the set water flow and are not affected by pressure differences in the system. The purchase costs, including installation, are between €80 and €200 per radiator (based on avg. installation costs in 2021). 

The government in some countries recognizes hydronic balancing as an additional energy saving measure. Reach out to your installer to find out more.

Yes, in some countries hydronic balancing has been mandatory for both new build and renovation projects since 10 March 2020. If the boiler or heat pump is replaced or upgraded in a dwelling, this counts as a renovation project and there is a requirement for the system to be properly balanced. When replacing a radiator, it must be possible to perform hydronic balancing and adjustment measures on the new radiator. If more than 30% of radiators are replaced, it must be possible to perform hydronic balancing for all the radiators in the system. 

Water 'chooses' the path of lowest resistance, so the question is: How does resistance arise? The higher the water flow, the greater the resistance and therefore the greater the pressure loss in pipes. This pressure loss increases as the speed of the water flow rises. If the pressure loss is too high, only a small amount of water will flow through the radiators furthest from the pump. On the contrary, too much water will flow through the radiators closest to the pump. When the amount of water flowing through the radiators is too high, it causes hissing noises and unnecessary energy loss. When the water flow is too low, it causes rooms to heat up slowly or issues with rooms that are not warm enough. 

Yes, the standards require heat meters to only be used on systems that are properly hydronically balanced. This is to avoid errors when drawing up bills. In addition to hydronic balancing, the water temperature in the system must be automatically controlled based on the measured outdoor temperature. As the outdoor temperature rises, the supply temperature of the water in the central heating system will be automatically reduced. Therefore, the "heat curve" of the weather-dependent control must be precisely adjusted for this to happen. Residents must be able to control the room temperature for each radiator using thermostatic radiator valves. This gives the residents more control over the level of heating and reduces their energy consumption. These measures prevent heat unnecessarily escaping from pipes through residences and storage rooms. As a result, the total energy costs are reduced, and heat consumption is distributed more fairly among households using heat meters fitted to radiators.