Hot water and Chilled Water Reset


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Working with chillers, you eventually hear the words, "cold water reset" This is located under the controls tab. We will select the setpoint control to OA reset This prompts us for a reset schedule We will select library to create one. The category will remain starting points. Then we will select "Schedule RESET-TEMP" Click Okay. And then click done. You'll see the reset schedule is defined and click done. This created a starting point schedule that we need to navigate to. On the left here, we select the Day schedule for Reset This allows us to edit the details First we will give the schedule a new name. Click okay when prompted Then, we can change our values to our design points. Enter our low control point of 50 And our high ambient control point of 80 degrees. Our maximum leaving water temperature is 55 degrees and our minimum temperature is 44 degrees. These are common control points. We can click done. Now we need to edit the weekly schedule. Locate it on the left and double click it. That take us to the properties screen. Again, we give it a new name. We will call it CHW Reset Week Click okay and then done. We will also edit the annual schedule and rename it CHW Reset. Click okay and click done. Then, locate the chilled water loop. Double click to open it. You'll see the reset schedule automatically updated it's name. Click done and now we will create hot water reset. Under controls, select setpoint control Select OA Reset as before Then select library Select RESET TEMP again. Click okay. Click done Select the Day Schedule again Rename the schedule again for consistency. Click okay again when prompted The defaults are the same as before However, we need different values. Enter 50 here. For the low temperature, enter 10. For the hot water temperature used when it is 10 degrees or below outside, enter 180 degrees When the outdoor air is 50 or above, we will use 160 degrees. Click done. Then, we rename the week schedule as before. Of course we need to rename the annual schedule too. You may wonder why we are renaming the schedules. This is because when we automatically create a reset schedule, it starts with the same name. Thus we couldn't continue to create new ones. Of course we need to rename the annual schedule too. In the hot water loop, controls tab, you can now see that our changes are implemented and we have hot water reset on our boiler.