With temperatures rising it's time to consider some cost-effective ways to beat the heat.

The least obvious way to cool off requires the help of Mother Nature. Large shade trees have a profound affect on the interior temperature of your home. Make a simple sketch of your home showing its location on your lot. Show it to a nurseryman or landscape professional and he, in turn, will recommend a size and type of tree, and optimal planting locations. Be careful not to overplant. Too much shade can block out the sun during the cooler months and result in mold and mildew in and around the house especially on walls that face north.

Decorative window awnings constructed of aluminum or canvas are another way to ward off the sun. A negative with awnings, as with trees, is they can make the interior of the home dark and uninviting. An alternative is a retractable awning that can be lowered when needed.

Insulation is a must for every home. Floor, wall and ceiling insulation are excellent ways to combat heat. During the winter, the insulation will hold the heat in.

Insulation can be added quite economically, especially if you install it yourself. Many local utility companies offer rebates or low interest loans as incentives to install insulation because it improves the energy efficiency of the home.

While insulation R-Values will vary regionally, a median guideline would be R-19 below floors, R-13 in exterior walls and R-30 in attic space. Many older homes either contain no insulation or an amount far below the current recommended value. Frequently, the existing insulation can remain and be added to, as in an attic, for example. Exterior walls can easily be retrofitted with insulation which is blown in through small penetrations made in the homes exterior at each stud bay.

Along with adding insulation, all exterior cracks, penetrations and gaps between windows, doors and other openings should be caulked and sealed. Use an exterior grade paintable latex caulk with silicone. Large penetrations can be filled with spray foam. As an added measure, all exterior doors and windows should also be weather-stripped.

Homes constructed with flat roofs where no attic exists can have rigid foam insulation applied above the roof decking and below the roof cover. This work can be done when it becomes necessary to replace the roof cover. Reflective paints can also be applied to many flat roofs.

A more expensive alternative, but one which will pay big dividends, is replacement windows. Upgrading from traditional single-pane windows to windows with insulated glass will make a huge difference on the amount of heat allowed to enter the home. Options such as low-E glass, tinting and reflective film will add to its efficiency. Again, check with your local utility company for cost incentives.

If window replacement is not in the budget, reflective window film is a less expensive alternative. Polyester sheets available in varying shades are applied to the interior of the glass. Due to better adhesives and superior material, today's reflective window films are finer than those of yesteryear which often left a homeowner with a wrinkled or scratched mess.

Many of the problems associated with this product are cosmetic and can be linked to faulty installation by the do-it-yourselfer. For this reason, much of this type of product has been pulled from home improvement centers, and manufacturers are recommending professional installation.

Film can reduce inside temperatures up to ten degrees or more and will even help to protect window coverings, furniture and floor coverings from fading. And, unlike shade trees and awnings, the reflective window film will not darken the home.

Window screens consisting of dense vinyl fabric are an excellent way to reduce heat. These are similar to traditional window screens, but the screening is installed over the entire window, rather than just over the openable section.

This is an excellent alternative, but in some cases can take away from the appearance of the home since the screen material hides any decorative window features like grids.

Ventilating the attic can do wonders to reduce the hot-box effect. The interior of an attic can reach temperatures well over one hundred degrees which will affect the living spaces below. Ceiling insulation will help, but can be aided considerably by exhausting the hot air to the exterior.

Attic ventilation can be achieved in a number of ways. The most common is the passive type sheet metal vents installed at the eaves, gable end or on the roof. This is the type of ventilation that is required by most building codes and is minimal.

The most effective passive attic ventilation system is a ridge vent. Here, the roofing material is removed at the roof's ridge and approximately two inches of roof sheathing is removed on either side of the ridge along its entire length. Ridge vent material constructed of fabric, plastic or metal is then placed over the new opening and roofing material is replaced. This method is most effective when ventilation exists at other areas of the roof as with eave vents.

Wind-driven turbines are another means of passive ventilation, but are not nearly as effective as the other passive methods.

Active types of attic ventilation, using thermostatically controlled electric attic fans, are very effective. The thermostat can be set to turn the fan on when the attic reaches a certain temperature and will continue to operate until the attic has reached the desired temperature. More than one attic fan may be required depending upon the size and configuration of the roof.

An advantage of the passive systems is that they operate without a power source. However, an electric attic fan uses only a fraction of the energy that an air conditioning system requires and will supplement the air conditioner, allowing it to labor less and save energy.