20:00 let’s say you have three modules and you measure the supply and return temperatures internally, isn’t there a formula that’d solve for the mixed temperature and would be pretty close to the external temperature sensor reading? My point is: can I skip the external temperature sensors if I had to, having good internal temp sensors ?
When cautioning against utilizing the BAS for control of a remote bypass valve should the takeaway be that the BAS NETWORK should not be used? That is to say the DP transducer and the remote valve should be hardwired to the same controller?
As discussed in the presentation, various strategies can be successful and actual operation depends on modular design and setpoints that are specific to each situation. The purpose of the comment was to call attention to a common pitfall where any control item passed through a BAS may be subject to a lengthy refresh rate. For certain systems this may simply slow down response, however it is important to understand that for a modular chiller system this could in fact cause issues. A system with fairly steady, slow-changing loads may not see much of a result, but a system with rapid load swings could see alarms/shutdowns. We encourage listeners to think about whole system performance then choose the best strategy for their goals.