Most homeowners like the convenience of portable air conditioner units, but venting is a problem for a room with only casement windows. According to Air & Water Inc., portable air conditioning units do not require permanent installation but require venting from a wall or window (see References). The AC unit works efficiently by exhausting hot air during the cooling process. Portable air conditioner units generally come with a standard window kit and use the kit to vent hot air to the outside. Casement windows open like a door and will not fit standard window kits. For this reason, homeowners will have to be resourceful and find air vents that will work with a portable unit. If not, the unit will not cool the room effectively and hot air will blow into the room.
Dryer air vents are a solution for venting a portable air conditioner unit in a room with casement windows. You will need to purchase two dryer vent kits to vent the unit. Two four inch holes are cut through the wall either to the side of the window or under the window. Portable air conditioner units usually come with an exhaust hose for the warm air that comes from the condenser. The holes are for running the exhaust hose from the air conditioner unit to the outside. From the outside, the dryer vents will appear as two neatly stacked vents. Mesh covering is also a way to protect the vents and to keep debris out of them.
Some alterations are a must when venting a portable air conditioner unit using casement windows. Plexiglas gives homeowners another option for venting. You will need to cover the entire window with Plexiglas and cut a five inch hole through the glass to run the exhaust hose to the outside. Foam strips will provide insulation to the Plexiglas by placing the strips around the edges. According to Sylvane, the standard length of an exhaust hose is five feet and overextending the vent hose will decrease efficiency (see References). The use of Plexiglas will still allow light to still come through the window.
Wall ventilation is another way to provide venting for a portable air conditioner unit. You will have to make a homemade vent for casement windows. The vent can exhaust the hot air outside, to another room or the garage. If you want the air to exhaust from the outside, then you will have to cut a hole next to the window. The jigsaw is the best tool for cutting the hole through the wall. A good size for the vent hole is around five inches or large enough to fit an exhaust hose. Find a place for the hole that is not near any wiring or plumbing. You will need to seal the edges of the hole with a silicone caulk.