Keeping the Heat Out of Your Home

The Heat is here!  What are you going to do about it?

One of the basic principles of thermodynamics is that “heat goes to cold”.  In other words, warm air is always seeking cooler air.  In the summer, this means that when the temperature is hotter outside, it’s trying to get into your house, (assuming it’s cooler inside).   Heat can be transferred through conduction, convection, or radiation.

An example of radiant heat is the solar gain that comes through your windows.  To reduce solar gain, concentrate your efforts on east- and west-facing windows because the sun angles are lower and the rays have a more direct path into your home.

• When replacing these windows, look for low “E” windows with a rating of .35 or less and  a solar heat gain coefficient less than .40
• Less costly options are solar shades, which are custom fitted and removable casings that allow you to see through the window.
• Window film is another option that provides visibility to the outdoors.
• At the very least, close the curtains
• Cheapest option:  aluminum foil, which blocks radiant heat very effectively.

An example of conduction is the heat transferred from your hot car into your garage when you get home.  Avoid putting hot objects in your home until they’ve cooled off, including autos, garbage cans, and indoor/outdoor furniture.

An example of convection is warm air coming into your home via open windows, poor weather-stripping and frequent opening and closing of doors.  Convection is also the phenomenon that occurs when the upper floors get warmer than the lower floors.

• You can use convection to cool your home in the evening by opening windows on opposite sides of and on different levels in your home.
• Set up a strong fan to blow air out an open window on the upper floor.  This will draw in cooler air below, which will force the warm air in the home to rise and exit upstairs via the open window.

The main idea is to keep your home as cool as possible in the first place, to reduce the need for mechanical cooling and increase overall comfort.  Once interior walls and furnishings have heated up, they will take a long time to cool back down.  This brings us to the final tip:

• Flush the home’s air in the morning before 8 a.m.  Open all the doors and windows and run fans for a half hour, then seal everything up tight.