Cool Tips for a Lower Electric Bill

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Real Estate


Home prices are high, so tips on saving money makes Hawaii a tiny bit more affordable. We are big advocates for solar PV panels, but also advocates for responsible electricity use, in general. The use of air conditioners (AC) is one of the bigger triggers to a high electric bill. Whenever possible, open the windows to let Hawaii’s trade winds cool your home. Set your ceiling fans to blow downward to create a wind chill effect. Turning on a fan instead of an AC can have significant monthly savings.


Use a tinting film, awnings, blinds or landscaping on south and west facing windows to block the afternoon sun. Solar window film or tint can reflect 80% or more of the incoming heat.


Medium-colored curtains with white plastic backings reduce heat gains from the sun by 33%. There are also solar blinds products to consider as well.


A solar-powered attic fan will draw hot air out and reduce attic temperatures. There are also ridge and eave vents to increase ventilation. Insulation in the attic can keep heat from transferring to your home. Feel the ceiling on a hot day, if it’s hot – these are possible solutions. Be sure to discuss these ideas with your roofing professional when roof work is about to be done. Light colored roofs and exterior surfaces will stay cooler. And if you already have a solar-powered attic fan, you might check that it’s still working properly before summer.


If you haven’t yet replaced incandescent light bulbs, CFLs and LEDs use 75% less energy, last longer and produce less heat.


When AC is necessary, find the right size for your home with the AC calculator on An undersized unit will not cool effectively. An oversized unit will result in inefficient performance and high humidity levels.


An energy star AC will be more efficient than standard models. A higher EER or SEER means the AC is more efficient. Clean the AC filter once of month and keep the cool air in by closing doors and windows when the AC is on. Set the thermostat as high as possible, each degree above 75 saves approximately 3% of the energy used to cool your home. While the AC is on, run the ceiling fans to help circulate the cool air. And do not set the AC to a colder temperature when you first turn it on as it will not cool faster. A programmable thermostat can turn off the cooling when the home is unoccupied.


Properly placed trees can reduce AC costs by 15-50% compared to an unshaded home. Here are some landscaping tips if you have some room to plant around your home:

·      Use native trees and shrubs on the warmer east, west and south facing sides of your home.

·      Plant trees on the south side to shade the roof, but be sure not to block solar panels

·      Plant medium size trees on the west side to block afternoon sun.

·      Shrubs and groundcover plants near driveways, sidewalks and lanai’s help reduce heat radiation.

·      Shrubs can shade walls, but allow space for air flow and avoid dense foliage next to walls, to reduce high humidity/mildew growth.

·      Prune plants near windows so they don’t block trade winds.

·      Shade AC units with trees, without blocking air flow around the condenser.

·      Use plants instead of fences and walls to form boundaries around properties.


A trees shade and the evaporation of moisture on its leaves can reduce surrounding air temperatures by as much as 9 degrees and temperatures directly under trees can be as much as 25 degrees cooler than the air above unshaded asphalt.


Be sure to plant trees that grow higher than 30 feet at least 30 feet away from overhead lines.