2.7 INTERNAL RECIRCULATION LOOP
The internal Recirculation Loop Assembly is located inside the unit enclosure at the rear of the
unit. In order to access this assembly, the right-rear panel must be removed, as shown in Figure
2.7.
This assembly contains a recirculation pump that connects the upper hot water outlet to the
lower cold-water inlet to the unit’s heat exchanger. The purpose of this loop is to provide feed-
forward (FFWD) temperature control by mixing a portion of the hot water outlet with the cold-
water inlet to the unit. Temperature sensors located in the hot water outlet and cold-water inlet
provide temperature data to the Edge Controller. The Controller utilizes this data to modulate
the fire rate (Air/Fuel Valve position) to precisely maintain the hot water outlet temperature at
the selected setpoint temperature.
REAR VIEW – REAR PANEL & EXHAUST VENT REMOVED
Figure 2.7. Recirculation Loop
To Next Page
Loading...
