edtpro
Industrial
- Nov 15, 2010
- 24
Our company does environmental testing for medical and surgery centers and I've run across something I need some help understanding. I have an OR that according to the plant ops dept has a master/slave VAV set up with the master reporting supply of about 1100 CFM and the slave reporting about 800. Therefore, he is expecting about 1900 cfm of supply going into the room. When I use an Alnor hood on the diffusers in the room I am only reading about 1100 cfm TOTAL supply. In addition, there are 3 return grills in the room that are reading a total of about 1400 cfm. The room is negative to the corridor (about -.005" wg) as I would expect with these readings.
Another OR has a master/slave setup reporting abbout 2000 cfm each. But, I'm reading about 2300 total supply, 1800 return/exhaust and a positive .003" presure to the corridor.
Can someone help me understand the way master/slave VAVs operate? Is it just a simple matter of adding the two together? Are we looking at a sensor/software issue? Thanks for any help.
Another OR has a master/slave setup reporting abbout 2000 cfm each. But, I'm reading about 2300 total supply, 1800 return/exhaust and a positive .003" presure to the corridor.
Can someone help me understand the way master/slave VAVs operate? Is it just a simple matter of adding the two together? Are we looking at a sensor/software issue? Thanks for any help.