summer cooling with natural ventilation in temperate and cold climates

Natural ventilation isn’t only a cooling strategy for hot climates. Natural ventilation can eliminate or drastically reduce the use of air conditioning in cold and temperate climates.

For the use of natural ventilation in hot climates, see: Home cooling Design for Hot Climates

Simpler Strategies

Common and simple natural ventilating strategies involve opening the windows of the house to capture cooler air or breezes during the coolest part of the day, namely during the night.

In temperate and cold climates, in hot weather conditions, consider ventilating the house with breezes or cooler air from nearby shaded areas till daytime temperatures are below 80-85ºF/30ºC (also do not forget to close the windows and doors during the other part of the time).

Breezes

Breezes can be directed to enter into the home by using fences, trees and other landscape elements, or architectural means. Wind creates areas of pressure that will move air into and out of the home as long as windows or other openings are conveniently located.

To capture the breezes the windows and openings hasn’t necessarily to face directly the wind path. Breezes blowing parallel to a wall can be sucked by open windows in that wall, by deflection (using casement windows, for instance).

Air from shaded areas

Breezes aren’t all. Air from shaded outdoor areas around a home can be sufficiently cooler to bring comfort to the home occupants, even without breezes.

This cooler air can be directed into the building by simply opening the windows - or by capturing the breezes using fans, pedestal fans or whole-house fans...

Openings location and air circulation

The windows or other air inlets and outlets should be properly located and dimensioned.

To maximize the air mixing (in cross ventilation) the openings in opposite sides of the home should be offset from each other. Openings directly facing each other will not favor air mixing.

Also do not forget to minimize the impact of inside obstructions to airflow. If the air inside the home doesn’t circulate properly, the effectiveness of ventilation can be lost.

Directing breezes into the house

The use of louvres and canopies can influence the direction and pattern of the breezes entering the building. See: Directing the breezes

Two-story homes

Two-story homes offer the ideal conditions for natural convection ventilation (using the natural buoyancy of hotter air, or chimney effect). Breezes (or cooler outdoor air associated to shaded areas) can be captured through low-located windows and inlets in the windy side of the 1st floor of the house, in order to exhaust the inside warmer air through windows or other openings located high in the rooms of the 2nd floor (on the leeward side of the house).

Obviously, this same strategy can be carried out for single story homes, using windows or openings that are low in the windward side of the home and high on the leeward side.

See, for more details: Convective Insulation (two-story homes)

The use of fans

For periods or situations when natural ventilation isn’t effective or desirable, fans – ceiling, pedestal, window and whole-house fans– can be a suitable and cheap cooling alternative to air conditioners.