Your case airflow has everything to do with the Noctua cooling capabilities it absolutely has to have fresh air input, some cases just do not provide that as they stand but sometimes you can do a little modding to get the airflow you need.
Below is a picture of repositioning my front drive bay and opening a direct airflow path to the Noctua.
You can also change out the cooling fans the pic below are Scythe Slip Steam 120mm 110cfm fans, to improve the cooling and looks IMO, I'm not crazy about the tan colored stock fans.
You can also see in the picture above the rest of the fans have been relocated outside the case, which also improves airflow.
Just a couple of suggestions.