Hot Weather Window Tips

The main source of heat gain through windows in the warmer months is from sunlight. Here are some tips for handling the sun that will help keep your house cool.

Install white window shades or mini-blinds. It’s a simple, old-fashioned practice. Mini-blinds can reduce solar heat gain by 40-50 percent.
Close south and west-facing curtains. Do this during the day for any window that lets direct sunlight in. Keep these windows closed, too.
Another good, old-fashioned solution is to install awnings. Awnings work best on south-facing windows where there’s insufficient roof overhang to provide shade. Canvas awnings are more expensive than shades, but they stop the heat on the outside of your building, and they don’t obstruct the view.
Hang tightly-woven screens or bamboo shades outside the window during the summer. They’ll reduce your view, but are inexpensive and stop 60 percent to 80 percent of the sun’s heat from getting to the window.
Plant trees or build a trellis. Deciduous (leaf-bearing) trees planted to the south or particularly to the west of your building provide valuable shade. One mature shade tree can provide as much cooling as five air conditioners (although they’re a bit difficult to transplant at that stage, so the sooner you plant the better).
Deciduous trees block summer sun, but drop their leaves to allow half or more of the winter sun’s energy to warm you on clear winter days.
Apply low-e films. Low-e films are thin metal coatings allow the shortwave radiation of solar energy to pass in, but block most of the long-wave thermal energy trying to get back out. Low-e films block most solar heat gain while transmitting most visible light. (See shop for supplies, below.)
Exotic infills. The other new technology commonly found in new windows is exotic infills. Instead of filling the space between panes with air, many windows are now available with argon, or krypton, exotic gas infills that have lower conductivity than air, and boost R-values. These inert gases occur naturally in the atmosphere, and are harmless even if the window breaks.

Read more: Home, Reduce, Recycle & Reuse

Excerpted from the Real Goods Solar Living Source Book, edited by Doug Pratt and executive editor John Schaeffer.Copyright (c) 1999, Real Goods. Reprinted by permsision of Chelsea Green Publishing Company and Real Goods.
Adapted from Real Goods Solar Living Source Book,edited by Doug Pratt and executive editor John Schaeffer.

Disclaimer: The views expressed above are solely those of the author and may not reflect those of
Care2, Inc., its employees or advertisers.

Tia P.

10:55AM PDT on Aug 27, 2008

You are right Jerry - evaporation is a cooling process, so as the water evaporates, it cools the air. That is the basis of how a swamp cooler works. However, this is only effective when the humidity is low. Adding evaporation to humid air makes it more humid and increases the perception of heat; in other words, it makes you feel hotter than it really is. That is why air conditioners are used in humid conditions - they remove humidity from the air instead by refrigerating it until the moisture condenses and literally falls out of the air. That is why air conditioning is so energy-consuming and expensive to operate.

send a green star

Connie M.

8:53AM PDT on Aug 27, 2008

Great tips! Thank you!

Jerry J.

11:55PM PDT on Aug 8, 2008

I believe that when I water my grass around my house in the evening, the air cools all around the house. Maybe that's just me. But you all try it and let me know if I'm wright.

Ronald D.

12:35PM PDT on Aug 15, 2007

Thanks for the tips.

Sandy M.

12:31PM PDT on Aug 15, 2007

Thank you for these easy tips to save money! We all need to save energy and these really are do-able.

Terri V.

8:40AM PDT on Aug 15, 2007

Good ideas!

Thomas P.

7:31AM PDT on Aug 15, 2007

Windows are cool and nice.