The Antec P150 enclosure comes with a 3-speed, 120mm TriCool case fan installed on the rear panel. The fan is setup to exhaust the internal case air out the back of the case along with the Neo HE power supply. Ambient room air enters the case thru openings in the front and rear.
As you can see in the previous picture, the stamped case fan grill is the open honey comb style that is minimally restrictive to airflow, especially at the lower (quiet) fan speeds. Hard-core purists may still elect to remove the stamped grill for maximum airflow with minimum noise. The slotted openings along both sides and across the bottom of the front bezel allow cool room air to enter the case. There is also an array of small holes above the expansion card slots on the back of the P150 for letting air into the case.
The Antec labeled fan has a maximum rating of 2,000 rpm, 79 CFM, 12.9W and 30 dBA.
A small 3-position selector switch is attached to the fan inside the case and allows selecting: low, medium and high speed operation. This lets the end user set the fan speed for the desired balance of airflow and noise.
When set to low speed the fan is virtually silent — at mid speed the fan becomes barely noticeable — but at high speed the fan will be considered rather noisy by most users.
Even though the P150 does not come with a front intake fan, Antec has made provisions for installing one or two 92mm case fans in front of the lower HDD bays.
Adding two low speed (quiet) 92mm case fans will further increase the P150’s already good case cooling capabilities. This option may be of particular interest to those running a large array of high-speed hard drives and/or high-end video cards