Keep Your Home Cool in Hawaiʻi

Practical energy saving tips for renters and homeowners, plus upgrades and rebates to know

Staying cool in Hawaiʻi is not just about comfort. It can also make a real difference in your monthly energy costs. That is why Lōkahi Federal Credit Union, in partnership with Hawaiʻi Energy, is launching a blog series focused on practical ways to better your energy efficiency.

This kickoff post covers cooling strategies that make sense for Hawaiʻi, whether you rent or own, and whether you live in a single family home, townhome, or high rise, with or without AC. Many of these are low-cost steps you can try right away. Others are longer term upgrades you can plan for over time, including options that may qualify for Hawaiʻi Energy rebates.

Things that work for almost everyone

These are low-cost moves that help in most situations.

Block heat before it gets inside

Closing blinds or curtains on the sunny side of your home can block up to 45 percent of sun heat from entering your home, especially in the afternoon. Also, using a light colored curtain or add a liner with a white or reflective backing helps bounce heat back toward the window. 

Let the trade winds work for you

When it is cooler outside than inside, open windows to let air flow through. A simple setup is to open a windward window for fresh air and crack a leeward window to let warm air escape. If you use a window fan, place it on the leeward side to blow hot air out and open a window on the windward side to pull cooler air in.

Use fans to feel cooler

Fans do not lower the room temperature, but they create a breeze that helps you feel more comfortable. Aim airflow where people are and turn fans off when no one is in the room. When using a ceiling fan, set it to a counterclockwise direction to create a downdraft that produces a wind chill effect.

Switch to LEDs where you can

Older bulbs can add heat fast. LEDs run cooler and use less energy.

Use smaller kitchen appliances for meals

If you are cooking something small, a toaster oven or countertop air fryer can use about one third to one half as much energy as a full sized oven. These efficient gadgets reduce heat in your kitchen and makes clean up easier.

Try induction cooking

Induction heats the cookware directly, so less heat spills into the room while you cook. If you rent, a portable induction burner can be an easy way to try this without changing your kitchen, just avoid sharing that outlet with other high wattage appliances. If you own, an induction cooktop or range can be a longer term upgrade, but it may require a dedicated higher voltage circuit, so check your specs and electrical setup first. Cookware needs to be induction compatible, and the quick test is whether a magnet sticks to the bottom of your pot or pan.

Watch the dryer heat, too

Dryers can warm up a space quickly. If you are running loads during the hottest part of the day, try shifting them earlier when you can. If a replacement is on your radar, heat pump dryers are a newer option that recycle warm air in a closed loop, do not require venting, and can reduce energy use compared to standard dryers. We will cover laundry and heat pump dryers in a future installment.

Window tint

If your space gets strong sun through the same windows every day, solar control window film can help reduce heat gain. In fact, they can block up to 50 percent of sun heat. If you live in a condo or have HOA or building guidelines, check with your building or property management before installing any film.

If you need to use AC, focus on the room you use most

A window AC can be an efficient way to cool one room. If a window unit is not an option, a portable AC can also work, but it needs to vent hot air through a window hose, and some models may need to be drained in humid weather. For the most efficient AC, look for ENERGY STAR^® certified dual inverter models with an efficiency rating (CEER) of at least 11.4. For any new cooling measure, be sure to check if your HOA, landlord, or building allows these.

Other AC options

AC options are numerous with many pros and cons to each. We’ll have a comprehensive guide to AC options in a future installment. When considering any new home cooling upgrades, use Hawaiʻi Energy rebates on qualifying models and installations.

Renters

Beyond the above tips, there are other strategies that can help make a noticeable difference without permanent upgrades.

Create a cool zone

Pick one room, usually a bedroom, and focus your effort there with shading, fans, and fewer heat sources.

Try renter friendly window upgrades

Removable shade solutions, such as blackout curtains and thermal liners with tension rods, can help a lot. Before you buy, it is worth checking whether your building has any preferences on curtain or liner color.

Homeowners

In addition to previously covered cooling strategies, homeowners may consider the following:

Pair AC with a fan

A ceiling fan can help you stay comfortable with the thermostat set a few degrees higher.

Consider upgrading to a more modern cooling system

If your AC is 10 plus years or older, or struggling to keep up, consider upgrading to a newer, more efficient system. An upgrade can use as much as 50% less energy and improve comfort. We will cover the different AC types and what tends to work best for different homes in a future installment.

Maintenance is key

A clogged filter or blocked vent makes your system work harder than it needs to, causing it to consume more energy. If your split or central AC system has not been serviced in a while, a tune up can help it run more efficiently. Hawaiʻi Energy offers a $75 instant rebate when the tune up is performed by a participating contractor. See the AC Tune Up rebate details.

If you have an attic

Heat can build up under the roof and make the rooms below feel warmer. Insulation can help slow heat moving into your living space. Some homeowners also look at a solar attic fan to help pull hot air out, and Hawaiʻi Energy offers a $75 rebate for qualifying models.

If window upgrades are on your list

If you are replacing windows anyway, focus on options designed to reduce heat gain from the sun. A good rule of thumb in warm climates is to prioritize a low Solar Heat Gain Coefficient (SHGC), and look for ENERGY STAR^® and NFRC labels so you can compare performance.

Townhomes

Upper floors often run warmer. Try shading and airflow upstairs in the late afternoon and evening, and close doors to rooms that heat up the most.

High rises and condos

Sun facing windows can turn a unit into a greenhouse. Curtains, shades, and fan placement matter a lot here. If your building has guidelines for window coverings or film, check before installing.

Ready to take the next step

If you’ve been thinking about some of these upgrades but they have felt out of reach, we’re here to help. Give us a call at 808.440.5380 and we can talk story about financing options for energy efficient and energy saving improvements.

FAQ

What are the easiest ways to keep a home cool in Hawaiʻi without AC

Start by blocking sun heat with curtains or reflective liners, using trade wind cross ventilation when it is cooler outside, and using fans to feel cooler in occupied rooms. 

Do fans cool a room

Fans do not lower room temperature, but they can make you feel cooler by creating airflow. Turn them off when no one is in the room.

What can renters do to keep an apartment cooler

Choose one room as a cool zone, use removable blackout curtains or thermal liners, and improve airflow with fans and window placement, without permanent upgrades.

Are Hawaiʻi Energy rebates available for cooling upgrades

Hawaiʻi Energy offers rebates on qualifying models and installations, including certain tune ups and equipment. Check the current rebate details and eligibility before you buy.