Although I knew there were some modest cooling challenges to the Evolv ATX chassis I could not resist using the case for my latest build. The Evolv ATX TG was just too aesthetically gorgeous to pass up. I knew going in that mounting my H115i up top would lead to some heat build up that I've seen posted about on the net. I've also seen plenty of suggestions here on this forum to address those concerns. Some very good ideas I believe.
But I am stubborn. I really did not want to shim the front panel out, nor rest the top of the case on its clips, nor cut into the case in any manner. All of those are very good tips to improve airflow, but I want to resist altering the case's outstanding good looks in any way. So, although some of those existing tips would indeed result in better temps than what I am proposing, I thought I would mention a very simple tip that helped drop my temps a few degrees in the top of the case.
As a variation to the existing tip about blocking the unused open spaces on the radiator tray to prevent hot air from recycling back down, I decided to experiment a little. I placed my 280mm radiator in the center of the tray leaving equal space "open" both in front and behind the ends of the radiator. I then blocked off the front opening so hot air could not circulate down from that area. Instead of also blocking off the rear opening, I left it open and instead moved my rear 140mm exhaust fan up as high as possible in the existing mounting location. My remaining air flow set up is comprised of 2 x 140mm intake fans.
By leaving the opening at the rear of the radiator and mounting the fan high in the rear mount, this allows some hot air to indeed drop down the rear opening (as the top unmodified cannot vent all the air pushed up by the AIO cooler as we know) but then flow immediately out via the rear exhaust fan. Sounds simple but it worked well. This setup improved my loaded CPU temps by almost 5c over blocking both openings, or shifting the radiator full frontward or backward and blocking the one remaining opening. The improvement comes from evacuating some of the heat that builds up in the top directly out the back, AND by reducing some back pressure against the radiator fans cause by blocking all the unused radiator tray openings. The top still gets warm, but its definitely cooler running.
Although I am not running as cool as I would using all the other tips noted above, this air flow set up produces my best temperatures while leaving all case panels in original position. I thought this might be good to share here.