Installing the NH-D15 is a breeze. You start by identifying which CPU socket you have, in our case it is the Intel LGA 2011-3, after that it’s as simple as following the detailed installation guide for that platform.
All of the different parts for the mounting kit are identified in the instruction guide with detailed illustrations and unique names, which make the process even easier as it eliminates the possibility of confusing components. In total there is about 6 steps to the whole installation process on our platform, but there will be others as you have to install the included back-plate for Intel’s mainstream 115x sockets.
The first step is securing the NM-IBT2 bolts into the threaded sockets on our motherboard, these bolts will provide posts for the mounting bars to attach to. Once we have them securely fastened, we then place the two NM-IMB2 Mounting Bars on top of the posts in the desired mounting position, making sure the holes on the bars are aligned properly with the posts.
Once the posts are on we’ll secure them with the four NM-ITS1 Thumbscrews, you may want to use a screwdriver to ensure they are properly fastened, but be sure not to use excessive force as you can strip the threaded sockets on your motherboard.
Once we have that sorted out, we then apply the thermal paste. We don’t go into details on how to do that, as there’s clearly no wrong way to do it (unless you’re putting it on your toast instead of the CPU, that’s obviously the wrong way to do it).
We’ll then place the heatsink itself without the fans installed on top of the threaded posts on the NM-IMB2 Mounting Bars, and then carefully tighten the spring-loaded screws onto the posts. You’ll want to tighten the screws until they stop, and not force it to go any further as applying too much pressure to your CPU can result in serious damage.
Once the heatsink is securely mounted to the motherboard, we’ll attach the fans starting with the first (center) one. When doing so, you’ll want to be careful with inserting the fan between the two towers as you don’t want to bend the fins on any of the stacks.
Its worth noting that while we had no problem getting the second fan to fit over our Crucial Ballistix Elite memory modules, it does stick out a few millimeters higher than the first one. This shouldn’t be a problem for most people looking at this cooler as most “enthusiast” level cases should have ample space to accommodate the added height. Still, users with memory modules taller than 45mm or smaller cases may have issues installing the second fan.
Speaking of fans, while the NH-D15 is technically capable of being used with up to three 140mm or 120mm fans, the extra mounting clips needed are not included in the box and Noctua does not sell them separately either. This means that if you wanted to get every last drop of cooling performance out of this cooler, you’ll be forced to improvise. That being said, Noctua says that they don’t recommend installing a third fan anyhow, as it does not affect performance enough to justify the extra costs and noise. Still, for some of us the option would be nice.