Cooling

Keep Cool When It’s Hot Outside

Here are a few ideas for ways to save energy and money when it’s hot outside!

Close outside doors, windows and blinds or curtains during the day when you’re out of the house, especially on the east and west sides. If safe to do so, open your windows at night or in the morning to let in cooler air.
Avoid producing heat inside during the hottest part of the day. Do laundry, run the dishwasher, etc., in the early morning and late evening hours when it’s cooler. Use an electric pressure cooker or a slow cooker instead of the oven.
Consider installing a whole-house fan to draw cooler outdoor air into the house in the evening hours so you can turn off your air conditioner (A/C).
Plant deciduous trees or install awnings to shade your home, especially on the south and west sides of your house. Before planting trees, make sure they won’t interfere with power lines once they grow to their full size. Refer to our Tree Planning Guide for more information.
Consider installing a ceiling fan in frequently used rooms. Moving air can make you feel up to four degrees cooler. Ceiling fans are helpful in homes both with and without A/C.
Turn off the A/C when you’re going to be gone for an extended period.

Selecting and Installing Central A/C

If your A/C needs ongoing, expensive repairs, or if it is more than 15 years old, you should consider buying a new one. A new higher-efficiency unit, when properly sized and installed, will cost less to operate.
If you want to reduce your operating costs, look for an A/C that has a high Seasonal Energy Efficiency Ratio (SEER). A/C payback periods for homes can be very long in our service area, due to our short summers.
Buying the correct-sized unit and installing it properly is critical to efficiency and comfort. Central A/Cs must be sized, installed and set up by a licensed HVAC contractor.
For the highest efficiency, consider purchasing an A/C with variable-speed motors for the outdoor fan and compressor as well as the indoor air handler. These variable-capacity A/Cs are the most efficient available and can also provide increased comfort with reduced noise. These systems are usually more expensive and have lengthy payback periods due to our short summers.
Ask a professional to inspect your duct system. Leaky, uninsulated or broken duct systems are common and reduce the effectiveness of your central A/C and heating system.

A/C Maintenance

Routinely check your system’s filter during the cooling season. Replace (or clean if reusable) as needed. Dirty filters block normal airflow and significantly reduce a system’s efficiency and life.
If you are experiencing a problem, have your A/C professionally serviced. Ask for a tune-up that includes a check of the refrigerant charge, cleaning of the coils and an inspection of your duct system.

Everyday A/C Tips

Don’t crank the temperature down to try to cool your house faster. It will not cool your home any faster.
Check your thermostat setting. Most people can be comfortable between 74-78 degrees.
Consider installing a programmable thermostat to allow automatic adjustments for higher temperatures at night and when you are away without sacrificing comfort when you need it.
Weather strip doors and caulk windows to prevent losing cool air to the outside and warm air from coming in.
Make sure there’s sufficient insulation throughout your home to help keep the heat out.

Selecting and Installing Window Room A/C

Shop for an ENERGY STAR certified unit. ENERGY STAR certified window room air conditioners use at least 10% less energy than models built to current minimum-mandated efficiencies and significantly less than older models.
For optimal operation, install the unit in a north-facing window of the room you would like to cool, or in a shaded area.
Consider a unit with controls, such as a digital readout for the thermostat setting and a built-in timer; both can help your unit use less energy. Some units will be able to be controlled through Alexa, Google or something similar.
Bigger is not always better. Purchasing a unit that is too large is less efficient because of increased on/off cycling. Use the following chart to determine the size you need. For room A/C units, size is measured in British thermal units (BTU), an indication of cooling capacity.

AREA TO BE COOLED (SQUARE FEET)	CAPACITY NEEDED (BTUS PER HOUR)
100 – 150	5,000
150 – 250	6,000
250 – 300	7,000
300 – 350	8,000
350 – 400	9,000
400 – 450	10,000
450 – 550	12,000
500 – 700	14,000
700 – 1,000	18,000

Make adjustments for the following circumstances:

Window Room A/C Maintenance

Clean filter monthly when in use. Wash foam filters with soap and water and air dry.
Vacuum the coil fins.

Everyday Window Room A/C Tips

Install a timer on the unit if you want the room cool when you get home. Check to see the timer is rated for the amperage and voltage of your unit.

Selecting and Installing a Ceiling Fan

ENERGY STAR certified ceiling fan/light combination units are 60% more efficient than conventional fan/light units. Savings come mostly from the lighting on the fan, so if your fan doesn’t include lighting, be sure to purchase an ENERGY STAR certified light kit.
For summer and winter savings, buy a reversible fan that will create a down-draft in summer and reverse to circulate warmer air near the ceiling in winter.
Install the fan with the blades at least seven feet above the floor, one foot below the ceiling and two feet from the nearest wall.
Consider the size of the room and the size of the blades when selecting a ceiling fan. Multiple fans may be needed in rooms longer than 18 feet.

Everyday Tips for Ceiling Fans

Switch the fan and light off when you leave the room. Fans don’t cool rooms — they cool people. When circulating air passes over your skin, it picks up evaporating moisture, making you feel up to 4 degrees cooler.
If your ceiling fan has a reversible motor, reverse the fan during the winter months to produce a gentle updraft, which forces warm air near the ceiling down into the room.

Selecting and Installing an Evaporative Cooler

Select a unit that has two or three blower speeds and a thermostat that automatically turns the cooler on and off.
Sizing an evaporative cooler is less critical than sizing an air conditioner. The suggested guideline is about 3 cubic feet per minute (CFM) of airflow per square foot of area to be cooled.
Place your evaporative cooler in a place free of outdoor obstructions, vents or combustion appliances. Make sure you can plumb a water supply pipe to it.

Evaporative Cooler Maintenance

Have your cooler serviced twice a year — once before the cooling season and once during the summer.
Have the unit professionally winterized before the winter season.

Everyday Tips for Your Evaporative Cooler

Evaporative coolers can cool outdoor air by about 15 to 20 degrees. The lower the humidity, the more effective the cooling is. Cooled air from an evaporative cooler will add humidity to your home.
Leave at least one window open while operating an evaporative cooler. The cooler air will go to the rooms with airflow and push the existing air to the outside.
During moderate temperatures ( 85 degrees or lower), use just the evaporative cooler fan to draw cooler outdoor air into the home without using the cooling media to cool the air.
Expect to use about one-third of the electricity needed to operate an air conditioner of similar capacity. However, your cooler will use anywhere from 3 to 15 gallons of water per day.