Cooling Your Property Naturally

Keeping the heat out of the building should have been his first line of defense. That can be accomplished four ways: first, installing thick, dense insulation in the attic and outer walls; second, blocking the sun from the windows either with a roof overhang, window awnings, or window coverings; third, shading the building; fourth, reducing heat-producing appliances and lights.

This hotelier opted to keep the original bricks and exterior framework. That decision prevented the use of thick insulation so the R value was inadequate to keep the interior cool in the summer. Insulation has improved since this renovation was done. Today, approaches to insulating the exterior walls could have given a high R value without modifying the exterior framework and facade. There are new insulations that give a high R value which contributes to guest comfort; as an added benefit, some don't contain formaldehyde. Dense-pack cellulose insulation is my favorite of what I've seen because of its higher R value, low energy use due to containing high amounts of recycled content, and low manufacturing pollution. Walls with a high R value will go a long way to creating interior comfort for your guests and your staff.

Windows allow about 40% of your heat gain into the building. By keeping the straight, unadorned exterior of the original building design, large overhangs weren't possible. They would have shaded the second floor windows in the summer, keeping those rooms cooler; the first floor windows wouldn't have been helped by four foot overhangs though. Window awnings would have also kept the sun out, and again keeping the rooms cooler, but would have changed the look and feel of the exterior. Exterior solar shades can also be effective in blocking the heat from entering the house. The challenge every architect has is balancing form and function. The form was authentic and original, but didn't help the function of cooling the house. Finding a way of imitating the original design while giving the functionality would have been ideal. Interior window coverings were used for keeping the sun and heat out, but inadequate because the heat was allowed inside before they could do any blocking. It takes eit

Shading the building was another option; shading can reduce interior temperatures by as much as 20 degrees F (11 degrees C). Being in a congested area with small lots and the need for ample parking limited his options in this approach to keeping the building cooled. Trees are a good way to shade a building; work with your local nursery to select the best tree so you can get the right height, spread and shape to give you your best shading. Vines, grown on trellises which are set away from the house so that air can circulate, also help to keep the building cool. Growing the vines on trellises keeps the plants from attaching themselves directly to the building facade, where damage can be done.

Venting the heat from the building was his second line of defense. Natural ventilation is an option that works best in climates of cool summers or cool nights, breezes being an important aspect of that equation. Open windows and doors and a whole-building fan are good venting options. Creating a chimney-effect where you bring cool air in lower levels of the building, say the basement or first floor, rises as it warms, and exits from openings higher in the building, is a viable passive venting system. Setting up such a chimney effect creates a low pressure system so more air is pulled in through the lower-level openings. Cross-ventilation, leaving doors and windows opposite each other open, is most effective when the ventilation path is long; that may require leaving some doors and windows closed so the air current travels a longer distance, effecting more cooling than a short path would.

The roof allows about one-third of the heat gain in building. Attic ventilation, where you have one square foot of vent per 100 square foot of ceiling space, evenly divided between soffit and rooftop, works to reduce heat gain from the attic. A vented attic can be about 30 degrees F (16 degrees C) cooler than un-ventilated attics. Attic ventilation in conjunction with attic insulation is the best way to block heat from entering the living space and remove heat build up from the attic. Turbine vents are valuable in that they catch any bit of breeze and pull heat from the attic space; I consider them active, natural ventilation -- a great benefit without using any electricity.

And finally, whole-building fans are affective in venting both the building and the attic space of heat. The biggest drawback to this approach is that it consumes electricity. Its advantage over natural venting is that it can accomplish the air exchange more quickly.

Of course, reducing heat sources from the inside will help too. Interior heat sources include lighting and appliances like the water heater, refrigerator/freezer, dishwasher, oven/range, and dryer. Vent the utility room directly to the outside to minimize heat transfer into the rest of the building. Buy energy efficient appliances because they not only use less energy but also generate less heat. Convert from incandescent to compact fluorescent bulbs to save energy and produce less heat.

Cooling strategies to consider:
* Walls/Windows
- install awnings or solar shades
- insulate
- plant shade trees and vines climbing trellises
- use heavy interior window coverings
* Interior
- isolate heat-generating appliances and directly vent that room to the exterior
- replace heat-generating appliances
- replace incandescent with fluorescent lighting
*Roof
- insulate
- lighten the roof color
- plant shade trees
- replace or coat roof with a bright, shiny metal material
- ventilate

Learn more from:
Green Builder

You also have "mechanical" ways of cooling buildings. Geothermal cooling, air conditioners, heat exchangers, and solar cooling.

Natural cooling is an ECOnomically Sound approach for your property.