How to connect pipes to the heating manifold whose diameter exceeds the cross section of its outlet pipes
Hello. Can outputs of different diameters be installed on the heating collector?
Evgeny.
Expert Answer
Hello, Eugene.
If I understand correctly, then you want to install the distribution manifold in an existing heating system. In this case, the purchased switchgear has output nozzles of a smaller diameter than the supply and return branches of the system, right? It is unfortunate that you did not provide accurate information about the parameters of the circuits used, and, nevertheless, I will try to help in this matter.
So, to connect to the heating manifold lines, the diameter of which exceeds the cross section of its outlet pipes, it is quite possible. Moreover, the advantage of this solution will be that the hydraulic resistance of individual circuits is reduced. This will increase the thermal efficiency of the system, and in addition, the circulation pump will operate in a more gentle mode. But this is only if the collector and the pump for pumping the coolant are selected correctly. Otherwise, narrowing of the sections and insufficient productivity of the pumping equipment will lead to thermal starvation of the heating system.
For this reason, it is imperative to calculate whether the collector can deliver at least 120 watts of heat to each individual branch per square meter of the area of the heated room. The cross section S of the outlet pipe of the comb can be calculated by the formula:
S = √354 × (0.86 × P / dT) / V, where P is the required amount of thermal energy in kilowatts (those same 120 W per square meter), dT is the temperature difference in the supply and return lines in degrees Celsius), V - coolant velocity (usually from 0.4 to 0.7 m / s).
In addition, be sure to calculate the size of the comb itself, otherwise its volume will not be enough to provide hot water to all circuits. This can be done both by special formulas, and using online calculators, which can be found on the Internet. To roughly estimate the size of the switchgear, add the diameters of all outgoing branches - the comb section must necessarily be larger than this value. Compare the results with the parameters of the distribution manifold that you plan to use, and you will have an idea if the heating can provide a comfortable temperature in the house.
