I am working on a OS model that has zone WSHP in a residential high rise (500,000 sf). On the condenser loop there is boiler and a cooling tower keeping the loop temp between 50-90F. The loop is set up with the boiler and cooling tower is series with a SP of 50F after the boiler and a SP of 90F after the cooling tower.
When I use a variable speed cooling tower the cooling tower doesn't keep the condenser loop below 90F and I get a ton of cooling hours not met. I have used all three variable speed cooling towers in OS (default, Cool Tools, and York) and I get the same result.
I have had this issue before and have been able to just use a single speed cooling tower and the loop is kept at the setpoint and my unmet hours go away. For some reason with this model, when I use a single speed cooling tower I get the following error :
* Severe * CoolingTower:SingleSpeed "1 SPD COOLING TOWER". Tower performance input method requires valid nominal capacity.
The nominal capacity is not an editable option for the cooling tower in OS. I know I can write a script to hard enter the nominal capacity, but I also want to know why this isn't working. I also am curious why the variable speed cooling towers are not working. Has anyone run into these issues? Does anyone have an idea on how to fix them?
Thanks
