I want to try to use less energy this summer. I know I will have to air-condition less, but I like it comfortably cool in my house. What things can I do to make me feel cooler with less air conditioning?—Linda L.
Using less air conditioning, especially during the hottest summer weekday afternoons, can save you money on electric bills while helping your electric cooperative reduce peak demand. This helps hold down future rate increases because less investment will be needed for additional electric generating plants.
It is possible to get by with much less summer air conditioning. After all, up until just a couple of generations ago residential air conditioning did not even exist. I recall when I was a child we had a window fan and a floor fan for a family of four. It got a little warm and we perspired, but we just accepted that in the summer, one perspires.
But summers don’t have to be all about perspiration. There are four good methods to keep comfortable without air conditioning:
1. bringing in cooler outdoor air when possible;
2. increasing the air velocity inside your house;
3. minimizing the indoor humidity level;
4. blocking heat transmission into your house.
Using all of these methods or a combination of a few can make a significant improvement. Once you become accustomed to the warmer ambient temperature, being in highly air-conditioned spaces will feel chilly.
Installing a whole-house fan accomplishes two of these methods. At night, it typically brings in cooler air and exhausts the hot air from your house. A large whole-house fan can also create a pleasant breeze throughout your house. A typical unit uses just a small fraction of the electricity a central air conditioner does.
By installing a solar chimney, the sun itself can be used to create a breeze throughout your house using no electricity. A solar chimney is a tall chimney made with standard lumber. Two sides of it are covered with clear acrylic sheets and the inside is painted flat black.
An opening at the base of the solar chimney is ducted through your house wall. When the sun shines through the acrylic on to the black interior, it gets hot and heats the air inside the chimney. Since hot air rises, it comes out the top and draws air in the bottom from inside your house to create a breeze indoors. To make it more effective, mount a turbine vent over the top outlet opening. A solar window heater with a summertime outdoor vent flap is another option.
Increasing the velocity of the indoor air can make a room feel 5 to 10 degrees cooler than still air at the same temperature. This is the theory behind using ceiling paddle fans. They use very little electricity and they can create a comforting effect—even though they actually make the room air slightly warmer.
During summer, set the ceiling fan blade rotation so it blows the air downward (turning counterclockwise as you look up) and run it on medium or high speed for the most comfort. During winter, reverse the blade rotation so the air blows upward (turning clockwise as you look up) and run it on low speed. This will gently move the warm air at the ceiling out to the walls and down. Since it is on low speed, it will not create a draft, which could feel chilly during winter.
If you plan to rely on natural ventilation through windows to use no electricity, hopefully you have casement windows. When the sash projects out from the house, it tends to catch and direct the natural breezes into your house more than vertical or horizontal slider windows.
If you do have sliders, all is not lost. Fully open the windows on the downwind side of your house. There usually is a slight lower pressure on this side so some air will be drawn from your house. Open the windows just a bit less on the windward side. This creates a faster airflow in through these partially opened windows, making you more comfortable if you sit near them.
Need a few more quick tips for keeping things cool?
• Run your kitchen and bathroom vent fans whenever you are cooking or bathing to remove the moisture.
• Use the summer weather as an excuse to grill outside more often and reduce the cooking heat in your kitchen.
• Make sure the clothes dryer vent duct is not leaking and allowing hot humid air to stay indoors.
• Block heat from entering your windows and glass doors with awnings and window film.
• Install reflective foil under the attic rafters to block radiant heat from a hot roof.
• Make sure you have adequate attic ventilation and that insulation is not blocking soffit vents.