Lets Orient Ourselves to the Texas Sun Path

Great home design starts with orientation of the home to the land and the sun. Unfortunately, most homes in TX are oriented to the plat and the street and not to the sun. But when we decide we have a problem with sun and windows, we do need to understand the path of the sun in the Texas year so that our modifications to windows make as much sense as possible.

The key principle to understand here is that the sun reaches its highest point in the sky in the northern hemisphere on June 21. At this time the sun reaches as high in the sky as it does all year and the sun path in the morning and evening is as far north as it will be all year.

This is the summer solstice at Fairview, TX on June 21. See image credit for more details. Each day the sun passes a little lower in height and a little farther south at sunrise and sunset. This zenith angle helps determine the size of overhangs on a well designed house. Most overhangs, alas, are just an afterthought.

This is the summer solstice at Fairview, TX on June 21. See image credit for more details. Each day the sun passes a little lower in height and a little farther south at sunrise and sunset.
This zenith angle helps determine the size of overhangs on a well designed house. Most overhangs, alas, are just an afterthought.

Each day the sun makes a path across your home that is an increment of the solstice path across  the equinox in September headed to the winter solstice.  At some point on the sun’s path, the orientation of  the sun and the overhang shading and the orientation of our windows and the configuration of your home  create a combination of attributes which causes the solar gain to cross over into a pain in the butt for the home inhabitants.

The overhang is a huge attribute to a well designed house. The summer sun, which we want to avoid is shaded. The winter sun whihc makes us warm and cozy is welcomed in. Windows can play a key role in energy efficiency. Without the overhang, we fall back to window replacment or the creattie use of window treatments to keep the unwanted sun out. Unfortunately most options also negate the winter sun also. Not all though.

The roof overhang is a huge attribute to a well designed house. The summer sun, which we want to avoid, is shaded. The winter sun, which makes us warm and cozy, is welcomed in. Window design can play a key role in energy efficiency. Alas, you are stuck with the structure and orientation you have. 
Without the overhang, we fall back to window replacement or the creative use of window treatments to keep the unwanted sun out. Unfortunately most options also negate the winter sun. Not all though.

Understanding these issues and understanding the circumstances that push you into the pain zone, are what define and outline what makes sense from a solar gain and comfort frame of reference for replacement windows or some creative use of window treatments.

Windows in the west contribute to overheating on already hot days depending on the orientation of your home’s windows and the size of the room being heated and your personal proximity to the photons, you can be overheated. Heating in the early morning happens with a east facing window and you usually in your favorite space experience the early morning solar spill. Again this takes a unique combination of temperatures, size of window, sun and orientation of the window to sun within a closed in space , to trigger the sense that the sun is making you too warm.

And not to overlook the blatantly bad design of windows on south facing walls not protected by overhangs. You see actual tall exterior walls with no overhang protection, and dormer windows, facing south. These create issues with upstairs overheating and, large solar gains in the house. These design defects underline the fact that issues with solar gain are as individual as the house and the address. These blatant issues are what call out for solutions.

As the sun retreats from its peak after June 21 to the Winter Equinox the sun that hits your home changes angle and the sun is able to reach directly into the window to give you warmth over the heating season.

This is low as the sun goes in North Texas. Here, the winter sun shines into windows and adds a little cozy warmth on a chilly day... when the overhang is designed right. Otherwise you get to solve window and sun heat gain issues.

This is low as the sun goes in North Texas. Here, the winter sun shines into windows and adds a little cozy warmth on a chilly day… when the overhang is designed right. Otherwise you get to solve window and sun heat gain issues.  image credit

Now you cannot easily change the structure of your home, but there are things you can do to reduce the impact on your home by solar radiation. You can change out the windows for better solar energy rejection and  better insulation qualities,  or you can add window treatments to manage the solar energy. To do this with thoughtfulness it is necessary to understand the path of the sun in Texas to design and implement solutions to too much sun.

Have some hot spaces at your house due to heating by the sun? Make sure you have a full perspective on all the components that impact your comfort in the home- we cover that here, but when the windows are radiating you with warmth and you don’t need warmth, it just might be time to figure out some solutions.

image credits: I swiped these great images from Paul Westbrook and a presentation he made in 2012. These images are part of a pdf – Thinking about the Box.  He has a great website too. Among many eclectic interests here, Paul gives a great introduction to his energy efficient home in Fairview, TX Westbrook House – EnerJazz Home. Paul has great pics of the shade lines on his house, these easily demonstrate the point of this whole page. You will find these pics in the pdf link above.

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