Success Story
BAScontrol-E36 Supports Variable Pressure Simulation for Education and Testing
When Francisco Barrantes attended AHR Expo 2025, he entered Contemporary Controls' 50th Anniversary Sweepstakes and won a BAScontrol-E36 36-point Edge Controller.
Barrantes is a BMS Design Engineer at Asesoria en Automatizacion Industrial S.A.(AAISA) in Costa Rica. For more than 20 years, AAISA has provided engineering services, specializing in HVAC systems for clean rooms and controlled environments in the medical device industry.
Barrantes has more than 35 years of experience in the building automation industry. As a BAS systems designer and consultant, he teaches basic HVAC courses, including control theory, sensing elements, actuators, and controllers.
"Once I had the controller in my hands, I began to think about how to use it proactively in my training for mechanical, electrical, and control engineers," Barrantes said.
He decided to use the BAScontrol-E36 to build a demonstration unit to simulate a variable pressure system using a (Proportional/Integral/Derivative) PID control loop, similar to those commonly used in air handling units (AHUs) that feed variable volume units (VAVs).
Figure 1: Variable Pressure demonstration system with BAScontrol-E36
Barrantes' objectives for the demonstration unit were:
- To demonstrate how a DDC controller regulates static pressure in a duct.
- To simulate different scenarios with varying pressure setpoints.
- To show how the PID control loop maintains constant pressure despite disturbances generated within the system, such as the opening and closing of VAV boxes.
One of the biggest challenges was locating a centrifugal motor-fan assembly that could generate reliable performance data, such as compression, flow rate, and power, on a small scale. Simulating static pressure in a duct and controlling it with a PID loop proved difficult.
After testing several fan types, Barrantes successfully implemented a centrifugal fan paired with a small duct and a variable louver, capable of simulating a static pressure control loop in the 0–0.5 inches of water column (IWC) range—a common pressure measurement in clean room environments.
Figure 2: Centrifugal fan 1/25 Hp, 1800 rpm, 143 CFMS
Then, a small variable speed drive (VFD) was added to handle a variable airflow rate from 0 to 60 Hz. The completed unit achieved a flow rate of 143 CFM at the duct discharge.
Next, Barrantes implemented BAScontrol-E36 which features 36 universal I/O points and supports BACnet/IP and BACnet MS/TP client/server operation. It is webpage-configurable and freely programmable using Contemporary Controls' Sedona Application Editor (SAE) which is included in the BAScontrol Toolset—a free set of software tools to configure, test, emulate, and archive controller operation on a Windows PC.
Figure 3: Block diagram PID demonstrator
"Contemporary Controls provided the BAScontrol-E36 controller and also instructed me on its use in Spanish," said Barrantes. "With simple yet powerful Sedona programming, I implemented a static pressure control loop capable of handling setpoints of 0.5, 0.1, 0.15, and 0.25 IWC."
Figure 4: Sedona programming with enhanced PID instruction and other instructions using the Sedona Application Editor (SAE)
The BAScontrol-E36 includes edge-connected features, such as a graphical dashboard for real-time PID loop performance, trend monitoring, and remote control. The controllers' programming capability allows users to remotely configure I/Os from a web interface and develop custom operating screens (GUI) from their own web server. These dashboards can display both digital and analog variables, generate trend graphs, and write/read variables of the same type.
Figure 5: BAScontrol-E36 Dashboard feature for temperature and pressure PID controls
"Users can turn the HVAC equipment on and off, change a setpoint, graph process variables, and create a complete system interface," said Barrantes. "This capability makes the demonstration unit an excellent educational tool. Additionally, the controller's USB-Wi-Fi accessory enables wireless access, allowing users to interact with the system without opening the controller's enclosure."
To learn more, visit the BAScontrol-E36 product page.