Natural Ventilation

Natural ventilation is fresh air. Operable fenestration (i.e. doors, windows, skylights and other vents) provides simple, direct natural ventilation into a building. Before the air-conditioned era, natural ventilation was the norm in most commercial and residential buildings. Since mechanical/chemical air conditioning grew widespread starting from the 1950’s, more fixed windows and less operable windows were employed, and fresh air was shut out of many buildings.

Today, operable windows and fresh air are back in style, esteem, and widespread use for providing indoor climate solutions. Natural ventilation is receiving renewed respect for its power to reduce energy consumption and global warming, as well as enhance personal comfort. Fresh air enhances personal comfort and offers psychological health benefits. Natural ventilation helps meet green building goals, and in fact this has been formalized so that LEED credits can be earned under Indoor Environmental Quality for Natural Ventilation, Daylighting and Views.

In addition to environmental benefits, lower energy consumption means cost savings on building operations. When buildings have natural ventilation systems centrally programmed to maintain median daily temperatures and to ‘rinse’ buildings nightly with outside air, less air conditioning is used during the day. Additionally, when buildings occupants are given accessible switches to control windows, skylights, and HVAC (Heating, Ventilation and Air Conditioning), occupants enjoy the feeling of personal control and feel more contented in their daily work.

A wide variety of commercial and residential projects are ideal for incorporating natural ventilation, including schools, universities, libraries, offices, gyms, and homes. Many buildings are suitable for retrofit; the Functional Fenestration Inc offices have been retrofitted with automated skylight ventilation, reducing average annual HVAC use by 20%. In the new construction arena, a growing number of American cities require LEED standards for new public as well as private buildings.

In the American media, most of the noise about global warming revolves around solutions to generate alternative energy, such as solar panels and wind farms. Therefore, the goal is providing energy to maintain current high levels of energy consumption. An equally important global warming solution should be to reduce energy use, with solutions as simple as natural ventilation and fresh air, as well as more and larger windows and skylights for more natural daylight and less electric light.

Natural Ventilation Solutions

Almost any operable fenestration (opening) can supply natural ventilation: awning windows (top-hinged), hopper windows (bottom-hinged), casement windows (side-hinged), parallel windows (hinged on 4 sides), sliding windows, skylights, as well as doors. Any of these can be automated with actuators. Additional commercial vents that can be automated include storefront glazing panels and curtain wall vents.

There are several recommended strategies to maximize fresh air in a building. Awning and hopper windows (horizontal pivot windows) are the most efficient at providing ventilation, as casement windows can be negatively affected by horizontal wind direction. Placing operable windows on varied elevations, i.e. some higher and some lower, creates the best pull-through of fresh air to cross-ventilate a building. Transom windows in interior walls encourage air to continue flowing. For higher windows that can’t be easily reached, automation provides ease of operation. Tall windows offer more ventilation and light. Functional Fenestration Inc has many products to support elegant fenestration for natural ventilation and daylighting, as well as for support passive solar heating and stack ventilation designs, including:

  Chain Actuators Awning, hopper, casement windows, skylights
  Linear Actuators Sliding windows; skylights
  Tilt Turn Systems Hopper/casement windows
  Lift Slide Systems Lift Slide Doors and Lift Slide Windows
  Multipoint Hardware Tall casement windows

There is a clear line from quality products to sustainable buildings that will serve green building goals. For more than 20 years, FFI has promoted high quality European hardware, from countries where homes, windows and doors are expected to endure for years to come. Also, FFI has many products with warranties that far exceed the competition, such as our 15-year warranty on stainless steel lift slide hardware, and 2-year warranty on most actuators. Choosing quality products that will last is a wise investment in green building and in the future.

Links to Green Building Information

Natural Vent
Natural ventilation concepts for architects, environmental engineers, and commercial and institutional building management.

Natural Ventilation
Natural ventilation, stack ventilation and wind ventilation.

US Department of Energy
General information on natural daylighting, passive solar, and more.

Mixed-mode Ventilation
Using a mix of operable windows, stack ventilation, and HVAC ventilation as needed.

Forest Stewardship Council
Certification for wood products that are sustainable and environmentally friendly.