SCARE: You do not need to cover the outdoor A/C unit; it could actually do MORE HARM than good in some cases. Many air conditioner units are built to endure snow and ice's harshness during the winter months. If you cover the air conditioner, it could trap moisture causing unnecessary rust or even lead to freezing condenser coils. Covering your A/C can also encourage animals to seek shelter under the cover, potentially causing them to get stuck inside and cause a breakdown.