No one likes to spend more than they need to on electricity – especially in Hawaii.
Hawaii residents pay more per kilowatt than anyone else in the country. It’s important to cut costs anywhere you can without sacrificing comfort.
What’s the most efficient way to run your AC?
Should you turn it off while you’re at work or just turn the temp up?
What else can you do to ensure your AC is running in top shape?
Each home is unique so let’s go over everything you need to know.

A/C Efficiency Tips
Running your AC unit in an efficient setting with proper maintenance can help you save money and stay comfortable.
- An efficient AC keeps your energy bills down.
- You can avoid overworking your system, leading to a breakdown.
- Your system will do a better job of keeping your air clean.
- Your home will stay at a consistent temperature.
At Island Comfort, we want to empower you with information to care for your system and save money. Use the tips below to make sure you’re following best practices for energy efficiency.
Turn It Off When You’re Not Home
It’s always best for your system and wallet to turn your AC unit off when you’re not home.
Some argue it requires more energy to start your unit up and pull the temperature down, but that’s not true. Leaving your A/C unit on requires more energy and overworks your system. Take any chance you can to give it a break.
If you have pets or your home gets overwhelmingly hot during the day, keep our unit on but turn the temperature into the high 70s or low 80s.
Set the Temperature as High as Possible
It’s tempting to set the thermostat low on sweltering days, but your AC won’t appreciate it.
You want to keep your thermostat set as close to the outdoor temperature as possible.
Keeping your AC unit at 75 (instead of 70) when it’s 90 out will prevent overworking the machine to keep the house cool. If you set it too low on hot days, your unit might never shut off.
Don’t Fiddle with the Thermostat
Set your desired thermostat temperature and leave it alone. Every time you change the temperature, your AC runs to keep up. You could end up running the unit longer than needed and waste energy.
Make Sure Your Windows and Doors are Well-Sealed
Hawaii’s jalousie windows are nice for drawing in cool trade winds but they do nothing to help your HVAC system.
Proper seals around your windows and doors prevent cool air from seeping out and warm are from creeping in.
It’s also smart to avoid running heat-generating appliances like ovens so your AC doesn’t compete with them.
Insulate Your Attic
Your attic is the barrier between the sun and your home. Have you ever touched a sunny rooftop? It’s extremely hot!
Without insulation, the heat from the sun penetrates and heats your home. Your AC unit must work overtime to keep the air cool. If you live on a sunny part of the island, your AC unit might never turn off!
Attic insulation can also prevent your freshly cooled air from escaping.
Change Your Filter Regularly
A clogged filter interferes with air intake. Your system won’t be able to pull in – nor blow out – sufficient air.
You’ll also notice your unit gets extremely dusty as debris accumulates around the outside of the filter.
Ideally, change your air filter every 60 to 90 days. If someone in your home has allergies or you have pets, change it every 30 to 60 days.
The EPA recommends filters with a MERV rating of at least 13 if your system allows it.
Keep Your AC Set to “Auto”
Again, it’s better energy-wise for your unit to turn on and off throughout the day instead of running constantly.
Setting your AC fan to “on” means it will never shut off – even after your home has reached the desired temperature.
Keep your thermostat on “auto” and set your temperature to around 75-degrees for ideal efficiency.
Make Sure Your Evaporator Coils are Clean
Dust from a dirty filter also builds up around your evaporator coils.
Your evaporator coils dehumidifies your air. When they’re dirty, your AC will blow out warm or balmy air.
Need cleaning or tune-up? Let the experts at Island Comfort handle it. We’ll also replace any faulty parts to prevent emergency repairs and charge your refrigerant.
Supplement Your AC with a Ceiling Fan
Ceiling fans don’t change the temperature of a room. They do, however, increase the wind chill which makes it feel cooler than it actually is.
For example, you could set your thermostat to 80 degrees but a ceiling fan would make it feel 76 or 75.
Your AC unit will run much less often if you can keep the temperature set higher. A ceiling fan only costs about 1 cent to run per hour. An AC unit, however, costs about 36 cents. You’ll save plenty of money.
Run the Appropriate Size AC Unit for Your Home
Every home has specific AC needs.
If you have a large home but rely on several small window units, you’ll definitely notice the cost of your electric bill. You’ll also waste more energy if your central unit is too small for your home.
In many cases, a ductless mini-split system can help you compromise.
Let our experts investigate your home, listen to your needs, and help you find the best system for your home. Installing a new system could save you money overall.
Consider Your Thermostat’s Location
Is your thermostat near a sunny wall? How about a drafty window?
If your thermostat is in an unusually warm place in your home, it will read a higher temperature than the rest of the house.
Your AC unit will continue running to keep up with that set temperature.
If you can’t move the thermostat, at least set it to a higher temperate to compensate for the warmer location.
Need a Tune-Up? Call the Friendly Experts at Island Comfort
Confused as to why your energy bill is so high? Annoyed by inconsistent temperatures? Our experts at Island Comfort will come to investigate and diagnose the problem with a smile.
You can count on us to find the best ways to save money without sacrificing quality and comfort.
Watch our videos to see what Island Comfort customers across Oahu, Kauai, and Big Island have to say!