Primary Loop Piping is commonly used in heating systems that run needing multiple temperatures or contstant temperature at the hydronic boiler is required.
Primary Loop Piping allows non condensing boilers to maintain a heat level in the boiler high enough to allow the boiler to run at its most efficient state. Primary Loop Piping keeps high efficiency boilers running more efficiency.
Primary Loop Piping also works well with condensing boilers allowing proper flow through the boiler for the highest rate of heat delivery.
Primary Loop with the same temperature as the Heat Source
Primary Loop with one temperature the same as the Heat Source and one temperature that can be lowered
Example of a 2 pipe primary loop with one zone set at the heat source output temperature and 4 additional zones with adjustable temperature.
The 4 additional zones can be adjusted as high as the heat source temperature or as low as needed.
The heating layout allows for a simple adjustment of the entire heating system output temperature as compared to outside temperature.
Many modern boilers (Either Condensing or Non-Condending Types) have an indoor outdoor reset capability and using thus piping layout will allow the most cost effective use of your boiler. Effective use of a single indoor outdoor reset acress the entire heating load.
Primary Loop with two mixing valves