Natural Roof Ventilation Design

When designing buildings for natural ventilation the design of the roof can play a significant role in the ventilation strategy.

Natural roof ventilation design.

Natural ventilation definition wind based ventilation cross ventilation natural ventilation definition cross ventilation. Although there are many different types of roof vents to choose from ensuring you have the right number of both intake and exhaust vents is a central part of roof design. Wind driven ventilation pressure driven flows and stack ventilation. There are three types of natural ventilation occurring in buildings.

The goal of roof ventilation is to get fresh relatively cool air into the attic and vent out hot moist air. Natural ventilation design contributes to energy efficiency in residential spaces while ensuring a supply of fresh air even without a mechanical ventilation system. Proper attic ventilation offers numerous advantages to the homeowner. And since hot air rises and is exactly what you want to vent out of your attic exhaust vents should always be installed at or near the top of the roof.

These attic or roof ventilation recommendations are based on a survey of building science literature combined with 40 years of building inspections on the observation of the locations of moisture mold ice dams condensation stains and other clues in buildings and on the correlation of. Roof ventilation choices design specifications. The pressures generated by the stack effect rely upon the buoyancy of heated or rising air. Wind moving past a building will create different areas of high and low pressure.

The use of natural ventilation to improve thermal comfort in warm periods is explained in more detail in the thermal comfort chapter. See design advice for specific building types in section 2 6 1. The windward side of the building is an area of high pressure while the leeward side roof are low pressure. Advantages of proper roofing ventilation.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. However the amount of ventilation depends critically on the careful design of internal spaces and the size and placement of openings in the building. As introduced in chapter 3 natural ventilation is a design strategy that can both reduce energy consumption and provide occupants with a positive psycho physical connection between inside and out. In buildings with attics ventilating the attic.

Intake vents located at the lowest part of the roof under the eaves allow cool. Section 1203 of the nyc building code allows property owners to deploy natural and mechanical ventilation independently or simultaneously. The specific approach and design of natural ventilation systems will vary based on building type and local climate.