There are several ways to beat the heat at home. An air conditioner (central, wall or window-mounted), a swamp cooler, a ceiling paddle fan and a portable tabletop fan are popular means. However, each of these systems will be required to work harder if an attic is not properly ventilated.

Most homes are required by building code to have passive attic ventilation such as eave, gable or ridge vents. Unfortunately, more often than not, passive ventilation is not enough to adequately reduce the 150-plus-degree temperatures that hot weather can generate in an attic. This "hot box" effect in the attic acts as a giant radiator, transferring attic heat to living space below. This compounds the cooling problem, and sends utility bills and tempers soaring.

The first step in keeping your cool involves beefing up passive ventilation. This usually means increasing the number and type of vents. For example, additional eave vents can be added, a gable vent can be installed where none exists, or a ridge vent can be installed. Wind-driven turbines also might be considered.

Insulation also keeps living space comfortable. Attic insulation should be up to par in terms of thickness and quality. Most climates require a minimum of R-38 insulation in the attic. Many homes contain less than half of that amount. What's more, old attic insulation often becomes compacted, a condition that significantly reduces its effectiveness.

Old, compacted insulation should be removed and replaced with new blown-in or batt insulation. Existing insulation that is not compacted and in good condition can be supplemented by simply adding more material until the desired thickness has been attained.

In addition to passive ventilation and insulation, there are active means that can make a marked difference in comfort and on the utility bill. Unlike passive ventilation, active ventilation systems employ mechanical equipment to exhaust hot air. Two of the most widely used are an attic fan and a whole-house fan.

An attic fan draws hot air out of the attic and discharges it to the exterior. The hot air is displaced by cooler air which is drawn in from vents located at the eaves. An attic fan is generally placed at one of the highest points on the roof. Where a gable exists, an attic fan can be affixed to the inside face of the gable. In either case, the fan requires an electrical circuit, and more than one fan can be installed depending on the volume of air in the attic.

There are three basic ways to operate an attic fan: use of a switch, a timer or a thermostat. When a switch is used, the fan will operate only when it is turned on. A timer will turn the fan on and off at appointed times each day. The one that we like the best is an integral thermostat which will automatically turn the fan on and off at pre-set temperatures.

Some people confuse an attic fan with a whole-house fan. While they perform much the same function, they are in fact quite different. A whole-house fan does everything that an attic fan does, and then some. The air movement caused by an attic fan is confined strictly to the attic. A whole-house fan, on the other hand, ventilates an entire house, including the attic.

A whole-house fan draws in fresh air through windows and passes it through the attic where it is exhausted through gable and other roof vents. You cool your home and attic at the same time, and get the added benefit of fresh air.

The louvered-shutter intake system of a whole-house fan is typically installed in the attic floor at a central location of the home such as a hall. Installation is relatively simple. First, check that the attic area where the louvered shutter is to be installed is free of electrical, mechanical or plumbing obstructions.

Use a template supplied by the manufacturer to cut a ceiling opening and remove the wallboard or plaster. Next, cut sections out of the ceiling joist where the fan will fit. Support the cut joists with headers between them. Frame the other two sides of the opening by installing blocking between the headers. Build a platform of one-by-sixes to fit over the perimeter of the opening for the fan to rest on. Complete the job by connecting electrical wiring to the fan and by installing the louvered shutter from below using screws.