Indoor Grill With Ventilation . #1 bathroom door air vent grille 455mm x 135mm / 18″ x 5.3 inch two sided ventilation cover t15. 65, 115, 215, 315 mm. ZHAONI Barbecue Grills Charcoal Indoor Outdoor Grill from www.amazon.com #2 bathroom door air vent grille by handua | perfect for restroom, warehouse, storage and storeroom doors | interior door transfer grill 404mm x 90mm (15.90″x3.54″) view product. The indoor grill is one of the greatest inventions around. 4.1 out of 5 stars.