About Cooling & Air Quality


Your home’s largest energy consumer is your electric water heater. Use our guide to learn about the most common types of water heaters used in Hawaii and decide on the best option for your home.


You can download the PDF here.


Air Conditioners

Air conditioners draw heat out of the house, then replacing the hot air inside with cooled air. Their effectiveness will depend on choosing the right type and size of system.

  • Central air conditioners (packaged unit) – Central air conditioners circulate cool air through a system of supply ducts throughout the home. Warm air flows back to the central air conditioner through return ducts and registers and is released outside the home. Ideal for single family homes with multiple rooms.
  • Central air conditioners (mini-split unit) – A split central air conditioning system is more commonly called a “Ductless mini-split system”. They differ from packed unit types in that, as their name suggests, they do not use ducts throughout the home. They are typically added as a retrofit where installing distribution ductwork is not feasible. Ideal for single family homes with multiple rooms.
  • Window or room air conditioners – Window or room air conditioners cool rooms rather than the entire home. If they provide cooling only where they're needed, room air conditioners are less expensive to operate than central units, even though their efficiency is generally lower than that of central air conditioners. Ideal for all types of homes.

    Click for available cooling rebates


    House Fans

    Fans are an ultra-efficient method of cooling, and can even reduce the need for AC (yes, we said it!) when positioned well. Know your fan types and how you can maximize chill:



    Dehumidifiers & Purifiers

    These days, air quality matters just as much as cooling. Learn the difference in equipment:

  • Dehumidifiers remove moisture from the air to reduce humidity. (Note: air conditioners already remove moisture, so you would not typically have both.)
  • Air purifiers or air cleaners remove contaminants from the air to improve your home’s breathable air quality.

    When shopping, look for the ENERGY STAR for products, which are at least 15% more energy-efficient than standard models.


    No matter what you’re using, aim for maximum efficiency.

    Cooling equipment is only as effective as the space it’s in. Good habits combined with equipment will ensure you get the most cool for your buck. Here are a few simple ways you can prepare your home:

  • Don’t waste your precious AC – make sure doors and windows are sealed well while using.
  • Heat from sunlight can force your AC and fans to work 25% harder! Close blinds and drapes ahead of time or while using.
  • Consider reducing indoor heat by cooking with non-oven/stove tools when you can. For example, microwaves don’t produce excessive heat and reduce energy use by 2/3!