heat gains control for cooling

Heat gains control is crucial in cooling strategies and involves shade, landscaping and insulation...

How to control heat gains

To get heat gains control you should…

1) control heat infiltration through windows and other weaker structures;
2) control heat infiltration coming from the sunlight striking onto the walls or onto the roof of the house
3) control the re-radiation and sun reflection in the surrounding ground areas of the home.

Means for heat gains control

In regions with cold, temperate and hot-mild climates, there are a well know set of methods that can provide comfortable inside temperatures: vegetation, overhangs, orientation of the home, proper sizing and location of the windows and mechanical devices like shutters, blinds or awnings.

If you live in hotter climates you should also consider other cooling methods like water ponds, ground covers, etc.

Shutters, awnings, ground covers…

Awnings, blinds and other mechanical shading devices are excellent means to contain heat gains.

In hotter climates, a filtered zone with ground covers is also advantageous to reduce the high summertime temperatures and the heat gains. They can act as a second line of outdoor cooling, besides vegetation…

Thermal mass

Thermal mass is a features you may want to consider in many climates.

High thermal mass materials (masonry walls, for instance) can act as heat sponges, absorbing heat in the sunny hours on hot days. But as they will also release the heat later, it may be necessary to use some nighttime ventilation and mechanical cooling (fans or even air-conditioning), preferably during off-peak cost hours.

In some cases, high thermal mass structures are designed to get the cool night air, in order to release the heat absorbed during the sunny hours.

See, for details and limitations: Thermal mass uses

Windows Size

Be aware with the glazing area of your windows, or with skylights. Large windows are excellent for cross-ventilation and cooling through breezes, but they can also be a source of over-heating (in summer...) or a source of unwanted glare and heat.

Even shaded windows with a modest size and a good type of glass (to avoid heat gains), can affect negatively the home’s inside temperatures.

Skylights and roof windows

Conventional skylights and roof windows are often a bad option in hot climates, mainly in the summer, when sun is higher in the sky. They can lead to very high solar heat gains, unless shaded...

In hot climates, if you want a skylight (for day-lighting…) prefer a sun-tunnel/tubular one. This new type of skylight is very effective at blocking the heat.

Heat gains through ground areas

Re-radiation and sun reflection in the surrounding ground areas of a building are typical source of heat gains. Vegetation, properly located, can eliminate or reduce it to low levels.