What is hydraulic balancing of a system?
It means balancing the flow of the heating medium (hot water) through the peripheral parts of the system (pipes, radiators, valves), aiming to provide a uniform temperature in all rooms heated or provide diverse temperatures, if such are the expectations of the user. Professional design of a system in theory takes into account all factors, but “cold” and then “hot” balancing is the responsibility of the contractor-installer.
An element of flow balancing is the appropriate gradation of the diameters of the pipes used (e.g. DN28-22-18-15), similarly as it happens in the human bloodstream, where the aorta branches into a network of thinner vessels down to capillaries. On the water return line from the boiler, identical diameter graduation takes place in the opposite direction DN15-18-22-28. Other factors of hydraulic balancing of the system include:
- Damping orifices;
- Presets of thermoregulation valves;
- Shut-off valves;
- Distributors with flow control.
What is the purpose of hydraulic balancing?
The heating medium (water) is the carrier of heat. Imagine that one molecule of water delivers one portion of heat. This means that the more water molecules flow through the radiator, the more heat will be delivered to this radiator. If a little amount of water flows through a large radiator, it will not heat well! Therefore, the amount of medium flowing through must be adequate to the radiator of any size.
From the boiler, a specified quantity of water is pumped into the circuit by means of a circulating pump. This water needs to be properly divided to all radiators in accordance with their heating demand (size). The circulation pump installed in the supply line pumps water into the circuit, and sucks it back on the return line. This means that after passing through each radiator, the water returns to the boiler.
What can be the result of a lack of hydraulic balancing in a system?
A new radiator is linked into an old system. The new radiator has a larger hydraulic resistance than the other old radiators. Only the old ones are emitting heat, the new radiator is lukewarm at best. It is ignored in the distribution of water. The solution is to tighten the valves (increase the flow resistance) in all the old radiators.
Two parallel radiators are linked into the system (without valves), one very small and one very large. Where will the water flow? Certainly, it will flow to the small radiator and then return to the boiler (suction). The large radiator creates a greater flow resistance. Water flows where it is easier and shorter. In the return line, it is sucked towards the boiler.
Two identical radiators are linked to the system, downstream the circulation pump, with pipes of the same diameter and the same length. One of them has a thermostatic valve, the other has no valves. Where will the water flow? Well, it will flow mainly through the radiator without a valve, since the thermostatic valve has a flow resistance several times larger than the radiator without a valve. The radiator with a valve will emit much less heat than the radiator without a valve.
Several identical radiators with fully open valves are linked into the system in parallel at different distances from the boiler. Where will the water flow? Mainly through the first radiator and back to the boiler. The flow, and thus the emission of heat by the second and subsequent radiators will become weaker, and the farthest radiators can be completely omitted…
Examples of poor operation of the system which is the result of a lack of or poor hydraulic balancing are plenty. Defective, uneven flow of hot water through radiators results in that the entire system does not cool water sufficiently, does not collect the appropriate amount of heat from it.
Water which is too hot returns to the boiler… The boiler overheats and works inefficiently. The whole heating process is not optimal, and even ineffective and inefficient. The premises are heated unevenly, and thermal comfort is unsatisfactory. Hydraulic balancing applies to systems with all types of radiators, as well as underfloor heating.
REGULUS ®-system radiators – characteristics
REGULUS ®-system radiators have a very low water capacity and low weight.
This is a particularly important feature in modern, controllable and programmable heating systems.
Small water charge in the heating system + low weight of radiators – small thermal inertia of the system – low cost of bringing the system to the temperature required for effective operation – easy energy saving by briefly lowering the temperature in heated rooms.
REGULUS radiators quickly start and quickly finish working after reaching the desired room temperature. Each additional heat gain (sunshine, waste heat) will be suitably discounted. REGULUS radiators guarantee maximum thermal comfort. The hotter the building the more justified is the use of these dynamically heating radiators. A necessary condition for the correct operation of the system with a low total weight of radiators is the correct hydraulic balancing. Their benefits will then be fully utilised.
A system with a large amount of water, through its large heat capacity, can mask design errors or effects of a poorly chosen boiler. They will be associated with higher operating costs. In the case of such a system, it is best to maintain a constant temperature of the medium (heating water), which in turn limits the ability to control the amount of heat input (e.g. spring, autumn).
Installation requirements for REGULUS®-system radiators:
- due to the low water capacity and rapid heat dissipation, radiators should be used in systems with forced circulation;
- the system should be built avoiding unnecessary bypasses, and above all “traps” entrapping air and impeding the circulation of the heating medium;
- the system should use a gradation of pipe diameters in order to obtain the correct hydraulic resistance distribution and uniform circulation of the heating medium through all radiators or adjustable distributors;
- radiators must always be installed horizontally;
- REGULUS®-system radiators are compatible with electric, gas, oil and solid fuel boilers equipped with automatics (subject to the applicable provisions specifying the conditions for the construction and operation of such systems);
- after installation, the system should be filled very slowly with the heating medium (avoiding turbulent flow) and carefully vented;
- after careful venting of the system and performing a leak test, perform the “hot” adjustment. It is usually performed by the installer. Users with appropriate knowledge can perform the adjustment themselves. This is usually done by presetting thermostatic valves (it is also possible to create orifices in the system or to throttle the flow on shut-off valves). After successful adjustment, the system should run evenly and quietly, and the boiler should turn on rarely for longer periods of time.
Failure to adjust the system will result in frequent and short turning on of the boiler (high fuel consumption), as well as noisy operation.
Other great advantages of REGULUS radiators is the large heat exchange surface, high thermal conductivity (copper + aluminium) and high resistance to corrosion.
WARRANTY – 25 years.