Solar Decathlon: window slats

First, the fundamentals. We've covered this before. The Earth's axis has a tilt of 22.5°. This is why we have seasons and why the days get longer and shorter as we orbit the sun. We here in Washington DC are located at a latitude of 38° (rounded for ease of math). So the sun never passes directly overhead even at the height of summer. Over the course of the year the angle the sun hits the southern exposure of the buildings changes from 38° at the Equinoxes... Equinoxii... Equinoxen?... Sept 22 and March 22 to 16° at the Summer Solstice (June 22) and to 60° at the Winter Solstice (Dec 22). By putting slats over your windows you can see out, keep out the summer sun, and let in more winter sun.

This side view of window slats shows how they offer varying protection based on the angle of the sun.

So obviously these would be popular at the Solar Decathlons.

These metal slats protect the deck. You can see that the slats are at an angle to allow in more winter sun than a standard horizontal model.



These two pictures show a fixed horizontal model modified to allow windows to open. A cable runs through the metal tubing that connects the slats.

These fixed horizontal slats are on tracks so they can be slid aside.

These were designed for shielding sliding glass doors. The whole thing slides aside and has the added feature of allowing sections to swing up to become huge slats that are spaced further apart.

QOk, but why would you want one on your house? Won't awnings do much the same thing?
AAwnings don't typically stick out far enough to provide the same solar protection and do very little except right around noon. Mostly they keep the rain off.

QI have blinds that can be easily lifted out of the way or adjusted to let in more light or block it completely.
ABut the sun has to come into the house before the blinds work. The outdoor slats keep the sun from getting in and heating the house.

They also offer the benefit of acting as shutters during storms. Hail and hurricanes are much less likely to smash your windows with slats over the windows. The rest of the house, however, is on it's own.