diff --git a/vitamins/psu.scad b/vitamins/psu.scad
index 6175ba7..e12eff2 100644
--- a/vitamins/psu.scad
+++ b/vitamins/psu.scad
@@ -39,6 +39,7 @@ function psu_face_grill(type)        = type[3];     //! Is this face a grill
 function psu_face_fan(type)          = type[4];     //! Fan x,y position and type
 function psu_face_iec(type)          = type[5];     //! IEC connector x,y, rotation and type
 function psu_face_switch(type)       = type[6];     //! Rocker switch x,y, rotation and type
+function psu_face_vents(type)        = type[7];     //! Vents array position x,y, rotation, size and corner radius
 
 function psu_name(type)              = type[1];     //! The part name
 function psu_length(type)            = type[2];     //! Length
@@ -166,6 +167,7 @@ module psu(type) { //! Draw a power supply
             fan = psu_face_fan(f);
             iec = psu_face_iec(f);
             switch = psu_face_switch(f);
+            vents = psu_face_vents(f);
 
             multmatrix(psu_face_transform(type, i))
                 translate([xo, 0, -t]) {
@@ -208,6 +210,14 @@ module psu(type) { //! Draw a power supply
                                     translate([switch.x, switch.y])
                                         rotate(switch.z)
                                             rocker_hole(switch[3], 0);
+                                if(vents)
+                                    for(i = [0 : len(vents) - 1]) {
+                                        // vent is of form: [ [pos.x, pos.y, angle], [size.x, size.y], corner radius ]
+                                        vent = vents[i];
+                                        translate([vent[0].x, vent[0].y])
+                                            rotate(vent[0].z)
+                                                rounded_square(vent[1], vent[2]-eps, center = true);
+                                    }
                              }
                         }
 
diff --git a/vitamins/psus.scad b/vitamins/psus.scad
index be98751..8d00c69 100644
--- a/vitamins/psus.scad
+++ b/vitamins/psus.scad
@@ -105,14 +105,23 @@ S_300_12 = [
             1.5,// thickness
             [],// cutouts
             false,// grill
-            [],[],[]// fan, iec, rocker
+            [],[],[],// fan, iec, rocker
+            [// vents
+                // [ [pos.x, pos.y, angle], [size.x, size.y], corner radius ]
+                for(x = [0:21], y = [-1,1]) [ [-7*x+215/2-34, (115/2-5)*y, 0], [3, 25], 1.5 ]
+            ]
         ],
         [// f_top, top
             [],// holes
             0.5,// thickness
             [],// coutouts
             false,// grill
-            [215/2 - 47.5, 115/2 - 37.5, fan50x15]
+            [215/2 - 47.5, 115/2 - 37.5, fan50x15],
+            [],//iec
+            [],//rocker
+            [// vents
+                for(x = [0:4], y = [-1,1]) [ [-7*x-215/2+48, 28*y, 0], [3, 25], 1.5 ]
+            ]
         ],
         [// f_left, front (terminals) after rotation
             [],// holes
@@ -140,14 +149,24 @@ S_300_12 = [
             1.5,// thickness
             [],// cutouts
             false,// grill
+            [],[],[],// fan, iec, rocker
+            [// vents
+                for(x = [0 : 21]) [ [-7*x+215/2-34, -25, 0], [3, 10], 1.5 ],
+                for(x = [0 :  1]) [ [-7*x, -1, 0], [3, 25], 1.5 ],
+                for(x = [0 :  2]) [ [-7*x-215/2+20, -1, 0], [3, 25], 1.5 ],
+            ]
         ],
         [// f_back, left after rotation
             [// holes, offset from center
-                [215/2 -  32.5, 15], [215/2 - 182.5, 15]
+                [215/2 - 32.5 - 13/2, 15], [215/2 - 182.5 - 13/2, 15]
             ],
             1.5,// thickness
             [],// cutouts
             false,// grill
+            [],[],[],// fan, iec, rocker
+            [// vents
+                for(x = [0 : 21]) [ [-7*x+215/2-34-13/2, 25, 0], [3, 10], 1.5 ]
+            ]
         ],
     ],
     // accessories to add to BOM