Control Options For Energy Recovery Ventilators

Greenheck offers a full range of control options for energy recovery units. From the basic offering of sensors mounted and wired by Greenheck to the advanced offering of a microprocessor controller, there are controls to fit nearly every application.

Sensors Provided by Greenheck

Greenheck's selection includes a standard offering of temperature, pressure, and current sensors that take measurements throughout the unit. The sensors are routed back to the unit control center to be interfaced with a field-mounted (by others) Building Management System (BMS) controller.

Space Temperature Control

Space temperature control is available on units with DX cooling, electric heat, or indirect-gas heat. The unit will be equipped with the following terminals to allow a room thermostat (provided by Greenheck or others), humidistat (provided by Greenheck or others), or BMS to send the following signals:

• A call for cooling
• A call for heat
• An occupied/unoccupied signal
• A call for dehumidification.

Discharge Temperature Control

Discharge temperature controls are available on models ERH, ERCH, ERT, and APEX.

Analog Discharge Temperature Control

The analog discharge temperature control is a series of unit-mounted thermostats that will control the following:

• Occupied/unoccupied mode based on BMS control or 7-day time clock (by Greenheck or others)
• Heating/Cooling mode based on outdoor air dry bulb temperature
• Discharge temperature will be controlled with a temperature sensor mounted at the unit discharge
• Discharge dew point will be controlled with a temperature sensor mounted after the cooling coil.

Microprocessor Discharge Temperature Control

One of the main advantages of the microprocessor controller is the ability to communicate with a BMS through networks such as Lon, BACnet, or Modbus. This allows the BMS to not only monitor the energy recovery unit, but also to control unit parameters.

The microprocessor controller offers improved control effectiveness through easy monitoring and adjustment of unit parameters by way of a LCD readout and a simple keypad. Some of the adjustable parameters include:

• Discharge temperature or room temperature (optional room temperature sensor)
• Discharge dew point temperature
• Occupied/Unoccupied schedule
• Heating and cooling lockout temperatures
• Time delays.

There are also many functions built into the controller to maximize the energy efficiency of the unit. Some of these functions include:

• Automatic supply discharge temperature reset that minimizes heating and cooling costs
• Automatic discharge dew point temperature reset based on a room humidistat (optional)
• Economizer control based on outdoor air temperature and supply temperature (optional).

Downloadable Greenheck Literature
Viewable with the Adobe Acrobat Reader
(Click here for more information or to download the Acrobat reader)

Catalog:

Energy Recovery Controls Catalog (374k)

Installation, Operation and Maintenance Manuals:

Microprocessor Controller (#469690) (424k)

Microprocessor Controller Start-Up Guide (483k)

Carel User Manuals :

Carel LonWorks User Manual

Carel PCO2 Modbus User Manual

PCOweb (BACnet) User Manual

Generic Carel User Manual

Carel Interfacing Boards:

PCO1000BAO PCOWeb (MSTP-RS485 Interface Board)

PCO1000WBO PCOWeb (Ethernet Interface Board)

PCO20000F0 (Lonworks Interface Board)

PCOS004850 (Modbus Interface Board)

Downloadable Controller Software

If interfacing Greenheck’s microprocessor controller with a BMS through LonWorks, BACnet, or Modbus, the following software may need to be downloaded. Please refer to the controller Start-Up screen to see what version of the software is installed.

BACnet (linked to Carel’s Website for BACset program download)
ER DDC1 v3.00 or v3.01

LonWorks
ER DDC1 v3.00 - Program Download
ER DDC1 v3.01 - Program Download