Existing Conditions
The existing boiler piping arrangement limits the temperature reset of the hot water heating to above 140°F, in order to protect the boiler from damaging flue gas condensation.
Retrofit Conditions
It is recommended that the boiler piping arrangement be changed to a true primary / secondary loop. This will allow the secondary (building distribution) loop to be reset below 140ºF while keeping the boiler water temperature above 140ºF. With this strategy, the building will not be overheated in low heating load conditions.
Further Benefits