Your air conditioning unit should not be covered during winter – or, for that matter, any other time of seasonal year.
It isn’t important to cover your outdoor air conditioning unit, even in the winter time. All external HVAC equipment is specially crafted to withstand harsh weather conditions and extreme temperatures from sweltering summers to biting winters.
However, if you live in an area that’s partial to hail you may want to cover your AC Unit – especially if there is an oncoming storm. Also, if you live in an area that sees blizzards, it is important to keep excess snow out of your AC Unit.
If you do need to cover your external AC Unit, one way of doing it is to use a large sheet of tarp and securing that with rope and duct tape.
Alternatively, you could purchase an air conditioner cover, which are relatively cheap!