Thursday, May 22, 2008

Building to the Weather - Part 4 of 7: Eaves, at work and play

Eaves do very important work.
From a practical perspective, they help to keep the rain water that drips off of a building's roof away from its walls. Water on the walls will become trapped water inside the walls, which quickly leads to mildew, mold, and rot. Similarly, eaves keep icicles from forming directly on a building's outer walls (an icicle on the wall can become an icicle dripping down the wall, leading again to water inside the wall).















Eaves that stick out 6" are just barely deep enough to keep rain off; a 9"-12" overhang is better. The Carriage House eaves shown here are 18" deep. Copper gutters - now worn out and removed - originally sat in the curved brackets running along the edge, adding 4" more depth as well as redirecting the water.

Eaves are also for play, of course - they make the carriage house fun to look at. And without eaves, this building would just be an awkward box with bumps. The length of the eaves, their edge moldings, and the rows of brackets underneath all come together to create a roof that visually shelters what's inside and delights the eye. The corbels facing both ways at the ends of the dormer windows and the at the barn's cornerssee the first photo) are just frosting on the cake.

The eaves here have another job - quite visible in the second picture. This is the south view of the western end of the barn - the eaves keep the summer sun from shining in the windows. This photograph was taken in early May, when the shadow line of the eaves is below the small windows in the stable - the sun will not shine in these windows again until late August. With the extra 4"of gutter, the windows would be shaded earlier and later in the year. Because the sun's path across the sky changes with the seasons (due to the Earth's tilt and rotation around the sun), in winter the sun will be low enough in the sky to shine below the eaves, and into those windows, bringing light and heat to the space inside.

That's a lot of creative 'green' stuff for an ordinary building detail to do. 


Here is the whole series:

Part 1 - http://www.jgrarchitect.com/2008/04/building-to-weather.html

Part 2 - How does the carriage house work with the sun to minimize wind chill?
              http://www.jgrarchitect.com/2008/04/building-to-weather-2.html

Part 3 - Why bother with a cupola?
             http://www.jgrarchitect.com/2008/05/thats-pretty-amazing-cupola-with-all.html

Part 4 - Eaves? they're important?
             http://www.jgrarchitect.com/2008/05/eaves-for-work-and-play.html

Part 5 - How a floor plan makes a difference:
             http://www.jgrarchitect.com/2008/06/no-tech-warmth-with-low-tech-aid.html

Part 6 -  A look at how these concepts were used at the Big House:
             http://www.jgrarchitect.com/2008/09/big-house-is-green-too.html

Part 7 - Shutters:            

             http://www.jgrarchitect.com/2008/03/shutters-ok-i-know-that-they-were-for.ht















Read Building to the Weather - Part 3.

Read 

Sunday, May 11, 2008

Building to the weather - Part 3 of 7: Original AC, or how to keep your barn from burning up, and your horses cool


 What a great architectural flourish at the top of the Park-McCullough carriage barn! An amazing cupola - with all its roof angles and arched vents.

It's also an important part of the cooling system. A vent at the top of a hay barn is essential: stored hay gets hot - hot enough to burst into flame. The vents let that heat escape out into the air.
They also help to keep the barn cool for people. Heat rises, so if there is an opening at the top of a building warm air trapped inside will escape. As that warm air goes out, replacement air has to come in from someplace else. If there is an opening - a door or window - lower down in the building, new, cooler air will flow in. If the vent at the top is smaller than the opening below, the amount of air coming in is greater than the amount that can easily go out. And more air wants to come in behind it! The air going out has to rush making a breeze.

In the summer, when the windows are open and the doors to the hay loft are open, a breeze will keep the carriage house, the workmen, and the horses cool.


Here is the whole series:

Part 1 - http://www.jgrarchitect.com/2008/04/building-to-weather.html

Part 2 - How does the carriage house work with the sun to minimize wind chill?
              http://www.jgrarchitect.com/2008/04/building-to-weather-2.html

Part 3 - Why bother with a cupola?
             http://www.jgrarchitect.com/2008/05/thats-pretty-amazing-cupola-with-all.html

Part 4 - Eaves? they're important?
             http://www.jgrarchitect.com/2008/05/eaves-for-work-and-play.html

Part 5 - How a floor plan makes a difference:
             http://www.jgrarchitect.com/2008/06/no-tech-warmth-with-low-tech-aid.html

Part 6 -  A look at how these concepts were used at the Big House:
             http://www.jgrarchitect.com/2008/09/big-house-is-green-too.html

Part 7 - Shutters:            
             http://www.jgrarchitect.com/2008/03/shutters-ok-i-know-that-they-were-for.ht