Voyager II and III – Energy Recovery Modules Operation and Control Ph.TISSERAND October 2010

Energy Recovery Module installation Easy installation of the two sub-assemblies Rooftop unit is designed to receive Energy Recovery Module (ERM). Rooftop will contain all control equipment : TR1-2800®, Economizer Module (ECA), Connection Terminal, Temperature sensors, defrost pressure switch/timer relay. Rooftop ERM

Energy Recovery Module installation Easy electrical connection into the rooftop Exhaust fan power cables and actuator motor cables prepared ERM Cables connected to terminal block inside the rooftop Installation and startup procedure described in document RT-SVX42A

Voyager II / Voyager III concept Mixing between return and fresh air is not managed in the rooftop but in the ERM Return air duct is connected to ERM Voyager III In PHE version, the mixing between return and fresh air is done inside the rooftop. Return air duct is located as the same place as standard rooftop unit. In ERW version, mixing between return air and fresh air is done inside the ERM PHE Exhaust fan treat only exhaust air flow. Exhaust fan is variable speed according to fresh air % Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence Condensation evacuate via drain pipe. ERW Exhaust fan treat 100% of the air flow (Return fan). Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation. No condensate to evacuate, moisture transferred between the 2 airflow.

Voyager II PHE 125-155-175-200-250-265-290-340 GDR FRD HTX BPD EXF ROOFTOP MXD FLT ERW 125-155-175-200-250-265-290-340 LVR Voyager II Mixing between return and fresh air is not managed in the rooftop but in the ERM Return air duct is connected to ERM PHE Exhaust fan treat only exhaust air flow. Exhaust fan is variable speed according to fresh air % Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence Condensation evacuate via drain pipe. ERW Exhaust fan treat 100% of the air flow (Return fan). Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation. No condensate to evacuate, moisture transferred between the 2 airflow. HTX FLT ROOFTOP MXD EXF GDR

Voyager III PHE 275-300-350-400-500-600 ERW 275-300-350-400-500-600 GDR ROOFTOP HTX BPD EXF FLT ERW 275-300-350-400-500-600 LVR ROOFTOP Voyager III In PHE version, the mixing between return and fresh air is done inside the rooftop. Return air duct is located as the same place as standard rooftop unit. In ERW version, mixing between return air and fresh air is done inside the ERM PHE Exhaust fan treat only exhaust air flow. Exhaust fan is variable speed according to fresh air % Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence Condensation evacuate via drain pipe. ERW Exhaust fan treat 100% of the air flow (Return fan). Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation. No condensate to evacuate, moisture transferred between the 2 airflow. HTX FLT MXD EXF GDR

Legend Modulating Fresh air damper Modulating Mixed air damper FRD MXD GDR Modulating Fresh air damper Modulating Mixed air damper With 0-10VDC / 24VAC actuator Gravity exhaust damper HTX Heat recovery exchanger EXF Exhaust fan BPD By-pass damper With 24VAC ON/OFF actuator Mixed air flow FLT Fresh air flow EU3 Air filter LVR Return air flow Fresh air weather louver

Key control components - PHE version Rooftop Supply fan Indoor rooftop supply fan (ON-OFF) VarioTrane TR1-2800 (Speed inverter) Power OUT Exhaust fan Power IN Reliatel controller (RTRM-RTOM) Outdoor air T° 2-10 VDC input Mixing/Fresh air damper actuator (Voyager II only) Return air T° Mixed air T° ECA module (Economizer Control Actuator) ON-OFF input By-pass damper actuator (ON in free-cooling mode) Defrost pressure switch / timer relay

Key control components - ERW version Rooftop Supply fan Indoor rooftop supply fan (ON-OFF) VarioTrane TR1-2800 (Speed inverter) Return fan Power IN Power OUT Fixed Reference Reliatel controller (RTRM-RTOM) Outdoor air T° Return air T° Mixed air T° ECA module (Economizer Control Actuator) 2-10 VDC input Mixing damper actuator Heat wheel motor (OFF in free-cooling mode) ON-OFF input

Energy Recovery Module operation ERM operation is following the rooftop fan and economizer operation ERM Exhaust fan Rooftop Supply fan Economizer Fresh air damper Unit status Unit Fan THP 03 Fan AUTO Without cooling / heating demand OFF 0% Unit OFF Ventilation mode Cooling mode Heating mode ON Min % Min % (PHE) 100% (ERW) Unit ON Unit in free cooling ON 100% Free cooling

Ventilation mode Fresh air setting The minimum fresh air opening is setup through the ECA minimum opening onboard potentiometer (0 to 50%). Minimum opening setting could also be given by Tracker / BCU or LON BMS. CO2 sensor option has to be used to adjust fresh air % according to occupancy. On PHE version, exhaust fan motor minimum frequency has to be adjusted through TR1-2800® parameter Mechanical Cooling - Heating Unit controls cooling and heating stages with the same logic as a unit without Energy recovery option. Defrost pressure switch / timer relay INACTIVE ECA VarioTrane Example for 20% fresh air setting on PHE – Voyager III version 3.6VDC 20% By-pass damper OFF ROOFTOP 100 20 20 20 20 80 20 20 100 100

Free cooling mode Example of 100% free cooling Free cooling initiation If the zone is calling from cooling, if Outdoor air temperature is lower than return air temperature, the free cooling will be enabled. In free cooling operation, the ECA will drive fresh air damper modulating from minimum opening to 100% depending of zone cooling need and mixed air temperature. Energy Recovery control The plate heat exchanger by-pass damper is controlled in open/close position depending of fresh air damper position. In free cooling mode, the by-pass damper will open, causing fresh air to flow beside the plate heat exchanger. So, Fresh air temperature will not modified by the heat exchanger. On PHE version, as fresh air introduction increased, the exhaust fan speed increased up to 100% in order to avoid building pressurization. Defrost pressure switch / timer relay INACTIVE ECA VarioTrane Example of 100% free cooling on PHE – Voyager III version 10VDC 100% By-pass damper ON 100 ROOFTOP 100 100 100 100 100 100 100 100

Defrost mode (PHE versions only) During cold period of winter, entering fresh air is at negative temperature. Condensate water on the exhaust side of the PHE could freeze causing pressure drop to increase. A differential pressure switch will sense the pressure drop on the exhaust air side of the PHE. When threshold set point is reached (Frozen PHE), the pressure switch initiate a 5 minutes timer relay that activates the by-pass damper actuator. In absence of heat exchange, exhaust air flow will melt the ice on the heat exchanger. During defrost cycle , the fresh air flow remains at minimum setting in order to be mixed with return air . Tempered air is introduced in the zone. Defrost pressure switch / timer relay ACTIVE ECA VarioTrane Example of defrost cycle on PHE – Voyager III version 3.6VDC 20% By-pass damper ON 100 20 ROOFTOP 20 20 80 20 20 20 100 100 Water evacuation

Thank you!