Removing ice dams by using of а transient air hole

The presence of ice crusts and icicles on roofs is an urgent problem since they influence the safety of people and property which are under cornices of roofs. There are a lot of methods to stop icicle formation on the roofs. But most of them are in need of expensive and complex equipment. At present article is used a way of stopping forming ice dams by creating a "cold attic". Tehnique of a transient air hole was offered to make it. The transient air hole can change its section area depending on wind speed. Such a constriction allows entering into the attic a big volume of cold air. Also, it helps to prevent a noise which is provided by a usual air hole. This concept was confirmed by a heat balance of the attic.