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).
Carel Interfacing Boards
- PCO1000BAO PCOWeb (MSTP-RS485 Interface Board)
- PCO1000WBO PCOWeb (Ethernet Interface Board)
- PCO20000F0 (Lonworks Interface Board)
- PCOS004850 (Modbus Interface Board)
- Microprocessor Controller v3.0 (#469690 IOM)
- Microprocessor Controller Start-Up Guide v3.0 (#469710 IOM)
- Temperature Control Package v2.0 (#461468 IOM)
- Microprocessor Controller - TAP v1.04 (#474706 IOM)
- Microprocessor Controller - TAPv2.0 (#474894 IOM)
- Microprocessor Controller - TAPv2.10 (#475595 IOM) (Pre November 2013)
- Network Interface Controller (#475262 IOM) (Pre May 2013)
- The Importance of ARI Certification
AMCA and ETL Certifications
Greenheck's Energy Recovery products are AMCA Licensed for Air Performance and ETL Listed. Click on the links below for a listing of AMCA Licensed and ETL Listed products.
AMCA Licensed Products
ETL Listed Products
To guarantee your customers are getting the performance they request, check for ARI Certification. ARI Certified products are tested for energy transfer effectiveness (sensible, latent, and total), cross leakage, and pressure drop. If a manufacturer states that their products are tested "in accordance with" ARI Standards that DOES NOT mean they are certified. To be certified, products must be tested by ARI and have annual check tests.
Click here for a listing of ARI Certified Energy Recovery products. Download the Supplemental Directory.
A psychometric chart is a design tool to graph a building's HVAC thermodynamic air conditions and processes. Properties displayed on a chart include dry-bulb temperatures, wet-bulb temperatures, dew point temperatures, relative humidity, humidity ratio, specific volume, and enthalpy. A link is provided to a downloadable software program that allows the user to electronically plot conditions on a psychrometric chart. This program version permits the user to enter state points and graph the air conditioning process, while also calculating additional air properties.
Click here to download the psychrometric charting software.
Help Text for Standard Version of Psychrometric Chart
Wording for ARI Certified Wheels, Options, and Accessories
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.