In parkings floors, in a high rise building, for a extended coverage of 400 sq ft per sprinkler head can I use ECOH with K=11.4 or else? Pressure here is not and issue.
K11.2 is about the smallest K-Factor you will get for ECOH. If pressure is not a concern, then the K11.2 should be a couple dollars less per head. Use Tyco EC11 or something comparable from Reliable or Viking (or any other you choose.)