système de chauffage à eau chaude à deux tuyaux

OBS: [Chauffage à eau chaude] Dans le chauffage à deux tuyaux [...] il existe des canalisations distinctes pour l'alimentation des corps de chauffe et le retour de l'eau chaude vers la chaudière. On distingue le chauffage à deux tuyaux à distribution supérieure ou chauffage en parapluie et le chauffage à deux tuyaux à distribution inférieure ou chauffage en chandelle.

CONT: Two-pipe hot water heating system ... Two-pipe system divides into two classification: the system with direct return and the system with the reversed return.
OBS: [Hot water heating systems.] Two-pipe systems. For large installations the supply of hot water needs to be kept separate from that water which has been cooled by passing through a convector. To accomplish this, one pipe is used to supply the hot water, which then empties into another pipe used for return. This type of system provides the water at as high a temperature as possible.