Cooling Mode

architects, cleveland, washington, sustainability, residential designLet’s take a look at passive cooling and how my home utilizes naturally occurring phenomenon and techniques to cool the space. However, you have to realize that the term “cooling” in this context is a relative term.  This approach will never give you the ability to have a 72 degree indoor air temperature when the outdoor air temperature is 90. Rather, this approach will provide you a relatively comfortable in door environment while reducing the consumption of planet’s non-renewable resources and just might leave our planet a little better.

The three primary components of a cooling system are insulation, reduced Sun exposure, and evaporation. All three components must be addressed with equal importance to ensure the maximum passive cooling effect. The insulation portion of the equation has been earlier discussed in “The Earth Mode” discussion.

If you also look at a previous discussion, “It’s Location”, you will see that the structure is oriented to take full advantage of the Sun and prevailing winds of Cleveland, Ohio. This however does create problems as the seasons change. During the winter, when it becomes desirable to use the Sun, we don’t want the wind. During the summer, when it becomes desirable to utilize the wind, we don’t want the Sun. The question now becomes what techniques do we utilize to both maximize and minimize these two naturally occurring phenomenon during the changing seasons.

Cooling and ventilating this home is achieved by century old techniques that reduces heat gain attributed to direct sunlight exposure and encourages air circulation by maximizing wind exposure. Sunscreens and appropriate roof overhangs are an integral part of the design and are used to reduce solar gain by blocking the Sun during the summer months while still providing daylight.

The interior volume of the home is designed as an integrated “windcatcher” used to increase evaporation by increasing air volume and air speed through the structure. The South elevation is the “intake”, the open interiors become the shaft, and the small north facing operating roof windows becomes the exhaust. By having a large intake and a small exhaust, the speed of the interior air currents increase in speed.

There are additional benefits as well. Combined with the simple rectangular plan, choice of materials, and open interior space, this cooling and ventilating system reduces the need for mechanical ventilation, improves indoor air quality, reduces the possibility of hazardous materials in the form of mold, and cools the home after the Sun sets.

Next we will discuss the actual construction of my home. You might want to look around your home or the neighborhood to become familiar with how it is done where you live.