I am trying to model a building with a direct evaporative cooler that serves multiple zones. My problem is that I am getting several hundred hours of unmet cooling loads per zone. Using hourly outputs I have calculated the effectiveness of the cooler based on supply temperature and outdoor dry and wet bulb temperatures. The effectiveness for the cooler maxes out at 51%. I ran multiple simulations, increasing the effectiveness input for the cooler from 0.1 up to 1.0. For each input the effectiveness I calculated from outputs increased until about 0.5. If I input anything higher than 0.5 it does not affect the cooler performance and the max calculated effectiveness is still only 51%.
Are there any ideas as to what is causing the evaporative cooler to lose effectiveness and not meet the loads?
Thanks for the help.
Adam Boyd
A follow up on my previous question on Evaporative cooling. I've done some further experimenting with the evaporative cooling system and found an interesting quirk in the results. When all systems are defined as evap cooling, then the cooling appears to work as it is supposed to in all systems. However, if a single system is changed to something other than evap cooling, PSZ for example, the unmet hours go through the roof for all the other evap cooling systems.
Attached is the simple file I used to perform the experiment. I can think of no other reason that this would occur other than it is a bug in eQUEST. If anyone can help me sort it out, I'd love to hear your thoughts!
Adam