Maintain CFM set point
I was thinking on how this systems from EBM can increase or decrease the motor rpm due to maintain the cfm set point when the duct impedance increase or decrease.
I saw that they are using a static pressure sensor but how they can manage the motor speed with the pressure?
I didn't watch the video, but can say that variable speed blower operation is done all the time by static pressure setpoint. The static pressure is measured by a transducer, which converts pressure to an analog electrical signal. A controller is then programmed to respond to this signal (the signal could be 4 to 20 milliamp or 0 to 10 volts DC) and send a similar signal to the variable frequency drive (VFD) which then ramps up or down according to what is needed to hold the static pressure setpoint.
Originally Posted by Domia
To maintain a consistent cubic feet per minute (CFM) setpoint would likely involve a different type of design than what I described above, which is commonly used for systems employing variable air volume boxes (VAV) in various zones throughout the building. With what I described above, the CFM will vary in order to maintain a constant static pressure.
- Electricity makes refrigeration happen.
- Refrigeration makes the HVAC psychrometric process happen.
- HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.
A building is NOT beautiful unless it is also comfortable.