"Most heat that accumulates inside a house comes directly from the sun shining on to the roof or through windows, and heating the house directly," says John Krigger, owner of Saturn Resource Management, which offers energy conservation training in Helena, Montana.Planting leafy trees around the building's exterior will stop the sun from shining inside your home. "Even for the cost of going to the nursery and buying a 15- to 20-foot-tall tree, trees are still the best value," Krigger says.If the trees or shrubs shade your air conditioner, you could increase your AC's efficiency by up to 10%, according to the U.S. Department of Energy.RATE SEARCH: Shop today for a home equity line of credit.Solar screens, or mesh-like window screens, intercept up to 70% of solar energy before it gets into the house, Krigger says. Window screens are particularly effective on east- and west-facing windows, according to the U.S. Department of Energy.Window films are another option. They are transparent, metalized sheets that reflect heat before it can be transmitted through glass.

However, windows must be shut for window films to work, while solar screens do double duty, keeping sun and insects out -- even with windows open.RATE SEARCH: Make your home more livable. Shop today for a home equity loan.Go ahead, get comfortable. Lower your air conditioner's thermostat setting to 78 degrees Fahrenheit when you're at home. But let that number rise to a higher temperature at night or when you're not at home. You can save 5% to 15% on your air-conditioning bills by raising the temperature setting on your thermostat when you're away and don't need cooling, according to the Department of Energy.RATE SEARCH: Make your home more liveable. No need to invest in fancy fans. Krigger says the key is to circulate air inside the house. If possible, operate fans on your home's upper level and open the windows on a lower level. If you live in a one-story house or apartment, you should close windows near the fan and open windows in rooms far from the fan, preferably on your home's windward side, according to the U.S. Department of Energy.Moving air also helps evaporate the sweat from your skin, says Paul Scheckel, an energy-efficiency consultant in Calais, Vermont, and author of "The Home Energy Diet."

RATE SEARCH: Time for home improvements? Compare offers for home equity loans."Evaporational cooling is an incredibly efficient process for removing heat, and our bodies do it all by themselves. A little help can increase the cooling effect," Scheckel says.Perry Mastrovito / DesignPics/Getty ImagesCamp out in your basement, says Stan Cox, author of "Losing Our Cool: Uncomfortable Truths About Our Air-Conditioned World (and Finding New Ways to Get Through the Summer)." In your eco-cooled basement, a TV, couch or futon, and a cold drink may be all you need.However, Scheckel says don't open basement windows when outdoor air is heavy with humidity. "Warm, moist air will cause condensation on cool surfaces such as basement walls, ultimately increasing the humidity in your home," he says.RATE SEARCH: Need to replace the AC or the roof? Shop today for a home equity line of credit.Skip the stove-top boiling and oven baking during hot spells, Cox says. Reduce indoor heat by making microwave nachos or eating a cool salad.

If you must boil pasta for tomorrow's potluck, cook in the evening.After cooking, turn on the kitchen exhaust, and turn on the bathroom exhaust fan after a hot shower. "Remove heat and moisture at the source," Scheckel says. "Reducing humidity can help increase comfort."recharge my home ac unitRATE SEARCH: Make your home better by getting a home equity loan today."mini ac unit no windowAC efficiency is mostly a function of the technology," Scheckel says. problems with unit root"Keep the filter clean to allow for good air movement and keep the unit level so the condensation drains properly."If you swap your older air conditioner for a newer unit, you could reduce your energy costs by half, according to the Department of Energy. Look for a high-energy-efficiency ratio, or EER, or an Energy Star-qualified unit.

Higher EER ratings mean a more efficient air conditioner. Energy Star refers to a system adopted by the U.S. Environmental Protection Agency and Department of Energy to identify energy-efficient products.RATE SEARCH: Invest in improving your home today with a home equity line of credit.Put the AC fan speed on high, except on especially humid days, says the U.S. Department of Energy. On humid days, place the speed on low. The slower air movement through the air-conditioning equipment removes more moisture from the air, improving comfort in your home.Compare offers for home equity credit lines.Step in the shower, spray yourself with a water bottle or use a cool cloth on the back of your neck. And if you don't chill out right away, don't give up, says Cox, the environmental writer and scientist. "Our comfort range depends on the temperatures we have experienced in recent days and weeks," he says. "The body and mind adjust to rising temperatures."RATE SEARCH: Make your home better by getting a home equity loan now.

As warmer weather taxes aging air-conditioning systems, the decision whether to repair an older rooftop unit or replace it with a newer, higher efficiency system may loom large for some commercial property owners.Most light-commercial HVAC products are for a life expectancy of 15 to 20 years. However, factors beyond the control of the original equipment manufacturer dictate the actual reliability and cost effectiveness of operating the equipment during its useful life period. That’s why it’s important to carefully examine each piece of equipment before reaching a decision to repair or replace a system. Understand the History of Your SystemA careful examination begins with the collection of all available information regarding the system, including records of the original installation, periodic maintenance, and repairs. If you do not have this information, contact servicing contractors and let them know you are evaluating your equipment to determine whether or not you will be replacing it.

Cooperation will usually follow, and you will have the opportunity to “size up” the contractor for consideration when doing future maintenance, repairs, or replacement.If you do not have a file on each piece of equipment, start one. In addition to the records you collect, be sure to include the manufacturer’s model and serial number, individual unit or site reference numbers, installation and operating instructions, warranty information, and factory- or contractor-backed service and maintenance agreements.Overall appearance of each unit will provide valuable information about the quality and attention to maintenance provided the unit. Inspect the equipment (or have a qualified technician perform the inspection), following the manufacturer’s instructions and safety warnings before removing any access panels.The cabinetry should be intact and fastened properly to minimize any air (or weather) leakage into or out of the unit. Filters, too, should be clean. Clogged or restricted filters reduce a system’s efficiency markedly, increasing the internal negative air pressure and pulling dust, dirt, and debris into the unit’s air circulating system.

Check the condition of the coils as well, looking for evidence of dirt, debris, or physical damage to the coils. Bent, damaged, or restricted coils restrict air flow, reducing unit efficiency and increasing operating costs.Arrange for a professional contractor to inspect each unit to assess its operating condition. If you can tie this to a periodic maintenance or repair call, you will save some expense. The inspection should include a complete operating review of the and portions of the equipment and an assessment of the airflow, temperature rise, and temperature split to be certain they are within the manufacturer’s specified ratings. Be present for the inspection and request that the technician review the findings with you, including the identification of problems and recommendations and quotes for corrective actions. Include this information in the unit files you have started.Review the Information You Have CollectedAt this point in the evaluation process, you likely have learned a lot about each system.

As you review the information you have gathered, determine and confirm the applicable manufacturer and contractor-supported warranty coverage that remains on each unit. Based on the records you have and inspections conducted, assess the condition of each unit. Equipment improperly maintained and serviced is likely to be less reliable and less efficient, resulting in increased operating costs and premature failures and repair costs. Consider the age of the unit, warranties or service contracts that apply, and the condition of the unit. Has it been well-maintained and what repairs are needed in the short term and the long term?Make the Decision to Repair or ReplaceStudying current operating expenses as well as projected repair and operating expenses better equips you to make the decision to repair or replace existing equipment. Compare these expenses to the operating costs of new, high-efficiency equipment. Most manufacturers can help you make this comparison by estimating operating costs based on unit efficiency and local utility costs.

In many cases, if your equipment is aged, new high-efficiency replacements will provide significant utility savings that can be factored as a “payback” in a decision to replace.A firm quote from your contractor will help you estimate the future costs associated with restoring a unit’s operating performance. Finally, as you make your decision to repair or replace, consider applicable utility rebates for the installation of high-efficiency equipment. Your local utility can provide rebate information that applies to your area.You should also consider potential savings that new equipment warranties will provide compared to out-of-warranty repair estimates. The purchase of extended warranties and scheduled maintenance programs offer additional savings worthy of your consideration. Often these warranties can be negotiated into the initial purchase price for new equipment and offer an affordable approach to future maintenance and repairs.Select a reputable local contractor who will offer future support or backup of their workmanship.