First off, thank you for taking the time to check this out.
On our campus we are running primarily pneumatic thermostats from Johnson, Seimens, and Honeywell. (Plus some older version of the same i.e. Powers, etc.) Before coming to my current position, I had not worked with pneumatics just DDC. I have been here for about 8 months and have gotten to know pneumatics pretty well. Shortly after I started (about a month or so) my department decided to desend on an air handler and map the system and calibrate everything. I got advice for proper calibration for dampers and valves from an experienced friend. Things were going well as no one before me had ever calibrated stats correctly. Now I am having to recalibrate these same stats a few months later.
Do pneumatic thermostats need periodic calibration?
Does a change in the weather/seasons somehow affect calibration?
For reassurance purposes, a satisfied damper should be at 50% for a hot deck/cold deck application, right? a satisfied radiant valve should be closed, right?
Double Check Senario
I have a multi-zone air handler running a hot deck and a cold deck. Zone 1 is an interior room with no radiant heat and a damper actucator with a spring range of 5 - 10 psi. Calibrating the thermostat to a satisfied temperature should have a 7 1/2 psi branch pressure, correct? Zone 2 is an external room with radiant heat valve of 3 - 8 psi and a damper actuator with a spring range of 5 - 10 psi. Calibrating this thermostat to a satisfied termperature should have an 8 psi branch pressure, correct?
This is what I have been doing per the advice from my experienced friend, seems logical and correct to me but want to double check...
Thanks for reading this far. If you have any thoughts or suggestions they would be greatly appreciated. And thank you in advance for any replies.