Achieving calculated continuous and unimpeded airflow through the roof cavity is relatively straight forward.
Passive vs active roof vents.
That hot air can condense and cause mold growth and rotting.
Active roof vents will exchange the air inside the attic with fresh air from the outside many times faster than passive vents.
It can also get trapped in the attic and cause quick melting of the snow which then runs down the roof and refreezes causing ice dams.
Whilst it is possible to retrofit passive ventilation solutions to existing buildings it is highly recommended to incorporate passive ventilation during the design phase of any new building project.
Exhaust out hot moist air in the summer and damp wet air in the winter with roof vents.
Good attic ventilation is important for preventing ice dams in the winter.
The most common types of active vents include wind turbines wire powered vents and solar powered vents.
The benefits of passive roof vents.
This is because active airflow is more consistent than passive airflow.
Sealing any air leaks between the house and the attic provides the most benefit.
A well insulated well designed home may only need to use active ventilation for rooms where moisture is generated bathroom laundry and kitchen while passive ventilation will be sufficient for maintaining air quality through the rest of your home.
Active ventilation is a system that provides air circulation in indoor spaces using mechanical fans.
A simple passive system uses no energy will work just as well for free as a powered active system and in almost all instances has the benefit of being silent.
Attic must have 5 sq.
Hip roof with not much space vents.
The best way to get air moving in an attic is by using powered vents.
Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.
This type of ventilation is especially important for.
Ft of vent space half dedicated for air intake in the soffits and the other half for exhaust on the roof.
Blowing in more insulation is another possibliity.
In order to facilitate this exchange of warm and cool air the general rule.
You don t want that kind of hot air in your house especially not in the winter.
Passive vents are fine powered vents are almost always a really bad idea.
These can be ridge vents wind turbines or the flat vents your roofer wants to install.