Home Appliances – Energy Consumption vs. Conservation

According to the EIA, U.S. residential, commercial and industrial customers consume 25 percent of the electricity generated worldwide, with more than 30 percent of that consumption, or 1.14 trillion kWh, used in homes. This seemingly high level of energy consumption in the residential sector can be attributed to the energy required to operate home appliances. Even though the efficiency of many appliances has improved significantly in recent years, the sheer quantity of appliances, ranging from large refrigerators to smaller toasters, hair dryers, and vacuum cleaners, in operation today creates a huge draw on the power grid.

Most of the larger wattage items like ranges and dishwashers can be significant energy consumers. They are only on for short time spans and do not use as much energy as the appliances that draw fewer watts but run continuously.

Refrigerator/Freezer – Top Energy Consuming Kitchen Appliance

There have been significant improvements in the overall energy efficiency of refrigerators/freezers over the past 30 years:

• In 1979 a typical refrigerator consumed between 120 and 300 kWh per month.
• Since 2001 the monthly consumption of newer models ranges between 31 and 64 kWh.

The difference is annual usage levels of 400kWh per year as compared to the 1970s energy usage levels of literally thousands of kWh. There are a number of factors to consider in selecting a refrigerator/freezer:

• Model size
• Freezer orientation (bottom freezers are more efficient)
• Temperature settings
• Placement

But, regardless of the model year and these factors, the following steps are recommended to further reduce energy use:

• Check for and use a power-saver switch.
• Set the thermostat for the refrigerator between 36 and 38 degrees F; and the freezer between 0 and 5 degrees F.
• Defrost when the ice build up reaches a quarter of an inch.
• Inspect (and replace as necessary) the seals.
• Establish common sense refrigeration habits (e.g. know what you want before opening the door, cool hot food before placing it in the refrigerator, and label food to reduce time required to find food).

Dehumidifiers – High Wattage and Extended Use

Dehumidifiers, prevalent in humid and wet areas, typically run continuously, drawing between 60 and 1,000 watts, depending on capacity. In fact, an average dehumidifier comes in at 785 watts, consuming 160 kWh per month. The primary drivers of energy use of an average dehumidifier are the length of time it runs and the setting of its humidity level. But there are other actions to take to ensure dehumidifiers act as efficient as possible:

• Close off the room where the dehumidifier is located to ensure it can efficiently remove moisture.
• In basements, avoid the continuously running of the dehumidifier by setting the  at 50 percent humidity.
• Use a digital reader for greater accuracy.

Water Heaters – Power Intensity Personified

Heating water reportedly uses 12 percent of  U.S. home energy use, averaging over 400 kWh per month. The primary drivers of this high level of energy use include:

• Type of water heater (e.g. standard, solar or without tank)
• Size
• Temperature setting
• Length of showers
• Use of hot vs. cold water in washing clothes

But, regardless of the model and specific water use habits, there are a number of measures that can be taken to improve energy efficiency:

• Set the thermostat equal to or below 120 degrees F
• Insulate the first 6 feet of pipes connected to the hot-water storage tank
• Limit the buildup of sediment by removing a quart of water every quarter
• Capture the energy in used water via the installation of a drain-water-heat-recovery system

Cooling System – An Ever-Increasing Requirement

The use of air conditioning in U.S. homes has more than doubled since 1980 (27 percent to 55 percent market penetration). The primary factors that determine the number of watts consumed in cooling a home include the type of unit, its capacity, time of operation and efficiency rating. Typically using between 200 and 1,800 kWh per month, the key variable is the specific device itself:

• Window units generally use between 200 and 650 kWh per month
• Heat pumps range higher between 600 and 1,800 kWh per month
• Central Air is surprisingly more efficient at 300 to 900 kWh per month

Specific steps can be taken to improve the overall efficiency of a home’s air conditioner, regardless of the device and the aforementioned operating factors:

• Inspect the unit annually for proper fluid levels, coolant charge and insulation
• Close vents in infrequently used rooms
• Purchase/install a programmable thermostat to automatically switch of the air conditioning as the outside temperature cools
• Ensure the attic is well insulated (at least 16 inches)

Heating System – Energy Hungry and Necessary

Viewed as one of the most necessary home appliances, the energy usage for heating systems ranges between 100 and 3,500 kWh per month. The type of unit is a primary determinant of a homeowner’s actual use:

• Electric Furnaces consume 1,500 to 3,500 kWh per month
• Heat Pumps consume between 900 and 2,000 kWh per month
• Portable Heaters operate on 200 to 300 kWh per month
• Baseboard Units use between 100 and 500 kWh per month

Besides purchasing an efficient heating unit, many of which operate at 97 percent efficiency, there are a number of relatively inexpensive measures that can be implemented to lower the energy use of heating systems, namely:

• Use a programmable thermostat
• Locate the thermostat away from sources of direct heat or cold
• Set the thermostat at the lowest possible temperature without sacrificing comfort
• Seal and insulate the ducts
• Remove all blockage from the vents
• Routinely replace filters