{"id":25448,"date":"2023-06-30T13:34:51","date_gmt":"2023-06-30T18:34:51","guid":{"rendered":"https:\/\/iaeimagazine.org\/?p=25448"},"modified":"2023-06-30T13:34:51","modified_gmt":"2023-06-30T18:34:51","slug":"energy-use-of-home-appliances","status":"publish","type":"post","link":"https:\/\/iaeimagazine.org\/electrical-fundamentals\/energy-use-of-home-appliances\/","title":{"rendered":"Energy Use of Home Appliances"},"content":{"rendered":"<p>How is the energy use of home appliances calculated? Let\u2019s start by looking at how you calculate the usage of power.<\/p>\n<h2><strong>Power Usage<\/strong><\/h2>\n<p>Let\u2019s start with the example of two cyclists who pedaled 10 miles and used the same amount of energy (218 calories). In this example, one has a faster time than the other. This cyclist demonstrated the most <em>power. <\/em><\/p>\n<ul>\n<li><strong>Power<\/strong> is the rate at which we do work.<\/li>\n<li><strong>Energy<\/strong> is the capacity to do work.<\/li>\n<li><strong>Work<\/strong> is the amount done.<\/li>\n<\/ul>\n<p><strong>Measuring Power<\/strong><\/p>\n<p>Units of power are not the same as units of energy (i.e., Btus, calories). Units of power are measured in terms of units of energy used per some unit of time.<\/p>\n<p>Examples of Units of Power include:<\/p>\n<ul>\n<li>Watt (W) = 1 joule of energy per second or 1 J\/S<\/li>\n<li>BTU per hour (BTUs\/h) = 1,055J<\/li>\n<li>Horsepower (hp) = 550 foot-pounds per second or 550 ft lb\/S<\/li>\n<li>Calories per second (cal\/sec)<\/li>\n<li>Kilowatt (kW) = 1000 watts<\/li>\n<\/ul>\n<p><strong>Calculating Power<\/strong><\/p>\n<p>Power can be determined by the following formula:<\/p>\n<p style=\"padding-left: 40px;\">Power = Energy (or work) \/ Time<\/p>\n<p style=\"padding-left: 40px;\">Or<\/p>\n<p style=\"padding-left: 40px;\">Energy = Power x Duration of Usage (Time)<\/p>\n<p><strong>Example<\/strong><\/p>\n<p>On a winter day, a home needs 1 x 106 or 1,000,000 BTUs of fuel energy every 24 hours to maintain the interior at 65\u00b0 F. At what rate is the energy being consumed in Watts?<\/p>\n<p><a href=\"https:\/\/iaeimagazine.org\/wp-content\/uploads\/2023\/06\/2023-03-EnergyUse-FIG1.jpg\" data-rel=\"lightbox-gallery-SgR7q8hs\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-full wp-image-25401\" src=\"https:\/\/iaeimagazine.org\/wp-content\/uploads\/2023\/06\/2023-03-EnergyUse-FIG1.jpg\" alt=\"\" width=\"838\" height=\"484\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p style=\"padding-left: 40px;\">If 1 J\/s \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 = 1 Watt, and 1000 Watt = 1kW,<\/p>\n<p style=\"padding-left: 40px;\">then 12,200 J\/<em>s <\/em>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 = 12,200 Watts<\/p>\n<p style=\"padding-left: 40px;\">= 12.2 kW<\/p>\n<p>&nbsp;<\/p>\n<p>To solve this problem, you must realize the following: You know the Power (1,000,000 BTUs\/24 hours) and the time (24 hours), so you need to solve for Energy. The measurements must be consistent, so the BTUs should be converted to a consistent measure, such as Joules:<\/p>\n<p style=\"padding-left: 40px;\">1 Watt = 1 J\/s and 1 BTU = 1,055 J<\/p>\n<p>If using Joules per second instead of watts, you must convert 24 hours into seconds or divide it by the number of seconds in an hour (3600).<\/p>\n<p>&nbsp;<\/p>\n<h2><strong>Power &amp; Cost of Energy<\/strong><\/h2>\n<p>We can also use a version of the Power formula to determine Cost of Energy:<\/p>\n<p style=\"padding-left: 40px;\">Energy Use \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 = Power \u00d7 Time of Power Use<\/p>\n<p style=\"padding-left: 40px;\">Cost of Energy \u00a0\u00a0\u00a0 = Energy Used \u00d7 Cost of the Unit of Energy<\/p>\n<p>&nbsp;<\/p>\n<p><em>Example<\/em><\/p>\n<p>If a 100 W light bulb is accidentally left on overnight (8 hours), how much energy does it consume?<\/p>\n<p style=\"padding-left: 40px;\">Energy Use\u00a0\u00a0\u00a0\u00a0\u00a0 = Power \u00d7 Time of Power Use<\/p>\n<p style=\"padding-left: 40px;\">Energy Use\u00a0\u00a0\u00a0\u00a0\u00a0 = 100 W \u00d7 8h<\/p>\n<p style=\"padding-left: 40px;\">= 800 Wh or 0.8kWh<\/p>\n<p>How much energy does this cost, if electricity costs 10 cents per Kilowatt?<\/p>\n<p>&nbsp;<\/p>\n<p style=\"padding-left: 40px;\">Cost of Energy \u00a0\u00a0\u00a0 = Energy Used \u00d7 Cost of the Unit of Energy<\/p>\n<p style=\"padding-left: 40px;\">Cost of Energy\u00a0\u00a0\u00a0\u00a0 = .8kWh \u00d7 10 cents<\/p>\n<p style=\"padding-left: 40px;\">= $0.08<\/p>\n<p>&nbsp;<\/p>\n<h2><strong>Energy Consumption<\/strong><\/h2>\n<p>We know that power is calculated by power = energy\/time or energy = power x duration of usage (time). By modifying this formula slightly, we can determine the energy consumption per day of appliances by applying the following formula.<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption \/ Day<\/p>\n<p style=\"padding-left: 40px;\">= Power Consumption \u00d7 Hours Used \/ Day<\/p>\n<p>Where:<\/p>\n<ul>\n<li>Energy Consumption will be measured in Kilowatt hours (kWh) &#8211; like on your utility bills.<\/li>\n<li>Power Consumption will be measured in Watts<\/li>\n<li>Hours used per Day will be the actual time you use the appliance.<\/li>\n<\/ul>\n<p>Since we want to measure energy consumption in Kilowatt hours, we must change the way power consumption is measured from watts to kilowatts (kWh). We know that 1 kilowatt hour (kWh) = 1,000 Watts hours, so we can adjust the formula above to:<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption \/ Day\u00a0 ( KWh )<\/p>\n<p style=\"padding-left: 40px;\">=\u00a0 Power Consumption\u00a0 ( Watts \/ 1000 ) \u00d7\u00a0 Hours Used \/ Day<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Example 1: Calculating Energy Use of a Ceiling Fan<\/strong><\/p>\n<p>If you use a ceiling fan (200 watts) for four hours per day, and for 120 days per year, what would be the annual energy consumption?<\/p>\n<p>Use this formula:<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption \/ Day\u00a0 ( KWh )<br \/>\n= Power Consumption\u00a0 ( Watts \/ 1000 )\u00a0\u00a0 \u00d7\u00a0 Hours Used \/ Day<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption per Day\u00a0 ( kWh )<br \/>\n=\u00a0\u00a0 ( 200\u00a0\u00a0 \/ 1000 )\u00a0\u00a0 \u00d7\u00a0\u00a0 4\u00a0\u00a0 ( hours used per day )<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption per Day\u00a0 ( kWh )<br \/>\n= ( 1\/5 )\u00a0\u00a0 \u00d7\u00a0 4 Energy Consumption per Day\u00a0 ( kWh )<br \/>\n=\u00a0 4\/5 or 0.8<\/p>\n<p>So, the Energy Consumption per Day is 0.8 kWh To find out energy for 120 days, do simple multiplication:<\/p>\n<p style=\"padding-left: 40px;\">0.8 x 120 = 96 kWh<\/p>\n<p><strong>Example 2: Calculating the Annual Cost of a Ceiling Fan<\/strong><\/p>\n<p>If the price per kWh for electricity is $0.0845, what is the annual cost to operate the ceiling fan?<\/p>\n<p style=\"padding-left: 40px;\">Annual Cost<br \/>\n= Annual Energy Consumption (KWh) \u00d7 price per KWh Annual Cost<br \/>\n= 96kWh \u00d7 $0.0845\/kWh<br \/>\n= $8.12<\/p>\n<p><strong>Want Another Example?<\/strong><br \/>\nIf you use a personal computer (120 Watts) and monitor (150 Watts) for four hours per day, and for 365 days per year, what would be the annual energy consumption?<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption\/Day (kWh)<br \/>\n= (270\/1000) \u00d7 4 (hours used \/ day) Energy Consumption per Day (kWh)<br \/>\n= 1.08<\/p>\n<p>So the Energy Consumption per Day is 1.08 kWh.<\/p>\n<p>To find out energy for 365 days, do simple multiplication:<\/p>\n<p style=\"padding-left: 40px;\">1.08 kWh \u00d7 365 days<\/p>\n<p style=\"padding-left: 40px;\">\u00a0= 394.2 kWh<\/p>\n<p>If electricity is $0.0845 per kWh, the annual cost would be:<\/p>\n<p style=\"padding-left: 40px;\">Cost = 394.2 kWh\u00a0 \u00d7\u00a0 $0.0845\/kWh<br \/>\n= $33.30<\/p>\n<h2><strong>Energy Usage of a Standard Refrigerator<\/strong><\/h2>\n<p>What is the energy consumption of a refrigerator with a wattage rating of 700 Watts when it is operated for 24 hours a day?<\/p>\n<p><strong>Step 1<\/strong><\/p>\n<p>To solve, use the following formula:<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption<br \/>\n= Power Consumption \u00d7 Number of Hours Operated<\/p>\n<p>Where:<\/p>\n<ul>\n<li>Energy Consumption = Watt Hours (Wh) or KiloWatt Hours (kWh)<\/li>\n<li>Power Consumption = Watts (W) or kW (KiloWatts)<\/li>\n<li>Number of Hours Operated = Hours (h)<\/li>\n<\/ul>\n<p>For the example above:<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption = 700 W x 24 h<\/p>\n<p style=\"padding-left: 40px;\">Energy Consumption = 16800 Wh<\/p>\n<p><strong>Step 2<\/strong><\/p>\n<p>To convert from Wh to kWh, remember that 1kWh = 1000 Wh<\/p>\n<p>&nbsp;<\/p>\n<p>To solve, set up as a ratio and use linear algebra to solve for ? 1 kWh\/1000 Wh<br \/>\n= ? kWh \/ 16800 Wh<\/p>\n<p>= 16,800 Wh (1 kWh) \/ 1000 Wh<br \/>\n= 16.8 kWh<\/p>\n<p>&nbsp;<\/p>\n<h2><strong>Locating Wattage<\/strong><\/h2>\n<p>You can usually find the wattage of most appliances stamped on the bottom or back of the appliance or on its \u201cnameplate.\u201d The wattage listed is the maximum power drawn by the appliance. Since many appliances have a range of settings (for example, the volume on a radio), the actual amount of power consumed depends on the setting used at any one time.<\/p>\n<figure id=\"attachment_25400\" aria-describedby=\"caption-attachment-25400\" style=\"width: 1350px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/iaeimagazine.org\/wp-content\/uploads\/2023\/06\/2023-03-EnergyUse-FIG2.jpg\" data-rel=\"lightbox-gallery-SgR7q8hs\" data-rl_title=\"Photo 1. You can find the wattage information on the bottom or back of many appliances. Credit: thefamily8(link is external) from flickr is licensed under BY CC 2.0\" data-rl_caption=\"Photo 1. You can find the wattage information on the bottom or back of many appliances. Credit: thefamily8(link is external) from flickr is licensed under BY CC 2.0\" title=\"Photo 1. You can find the wattage information on the bottom or back of many appliances. Credit: thefamily8(link is external) from flickr is licensed under BY CC 2.0\"><img decoding=\"async\" class=\"size-full wp-image-25400\" src=\"https:\/\/iaeimagazine.org\/wp-content\/uploads\/2023\/06\/2023-03-EnergyUse-FIG2.jpg\" alt=\"Photo 1. You can find the wattage information on the bottom or back of many appliances. Credit: thefamily8(link is external) from flickr is licensed under BY CC 2.0\" width=\"1350\" height=\"1013\" \/><\/a><figcaption id=\"caption-attachment-25400\" class=\"wp-caption-text\"><strong>Photo 1.<\/strong> You can find the wattage information on the bottom or back of many appliances. Credit: thefamily8(link is external) from flickr is licensed under BY CC 2.0<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>A refrigerator, although turned \u201con\u201d all the time, actually cycles on and off at a rate that depends on a number of factors. These factors include how well it is insulated, room temperature, freezer temperature, how often the door is opened, if the coils are clean if it is defrosted regularly, and the condition of the door seals.<\/p>\n<p>To get an approximate figure for the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three.<\/p>\n<p><strong>Table 1<\/strong> shows the wattage of some typical household appliances.<\/p>\n<p>&nbsp;<\/p>\n<table>\n<thead>\n<tr>\n<td colspan=\"2\" width=\"671\">\n<p style=\"text-align: center;\"><strong>Power consumption (Wattage)<\/strong><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Appliance<\/strong><\/td>\n<td width=\"315\"><strong>Wattage (range)<\/strong><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td width=\"356\"><strong>Aquarium<\/strong><\/td>\n<td width=\"315\">50 &#8211; 1210<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Clock Radio<\/strong><\/td>\n<td width=\"315\">10<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Coffee Maker<\/strong><\/td>\n<td width=\"315\">900 &#8211; 1200<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Clothes Washer<\/strong><\/td>\n<td width=\"315\">350 &#8211; 500<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Clothes Dryer<\/strong><\/td>\n<td width=\"315\">1800-5000<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Dishwasher<\/strong><\/td>\n<td width=\"315\">1200-2400<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Dehumidifier<\/strong><\/td>\n<td width=\"315\">785<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Electric Blanket &#8211; Single\/Double<\/strong><\/td>\n<td width=\"315\">60 \/ 100<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Fan &#8211; ceiling<\/strong><\/td>\n<td width=\"315\">65 &#8211; 175<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Fan &#8211; window<\/strong><\/td>\n<td width=\"315\">55 &#8211; 250<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Fan &#8211; furnace<\/strong><\/td>\n<td width=\"315\">750<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Fan &#8211; whole house<\/strong><\/td>\n<td width=\"315\">240 &#8211; 750<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Hair Dryer<\/strong><\/td>\n<td width=\"315\">1200-1875<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Heater (portable)<\/strong><\/td>\n<td width=\"315\">750 &#8211; 1500<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Laptop<\/strong><\/td>\n<td width=\"315\">50<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Microwave Oven<\/strong><\/td>\n<td width=\"315\">750-1100<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Personal Computer &#8211; CPU &#8211; awake \/ asleep<\/strong><\/td>\n<td width=\"315\">120 \/ 30 or less<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Personal Computer &#8211; Monitor &#8211; awake \/ asleep<\/strong><\/td>\n<td width=\"315\">150 \/ 30 or less<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Refrigerator<\/strong><\/td>\n<td width=\"315\">725<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>36<\/strong>&#8220;<strong> Television<\/strong><\/td>\n<td width=\"315\">133<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Toaster<\/strong><\/td>\n<td width=\"315\">800-1400<\/td>\n<\/tr>\n<tr>\n<td width=\"356\"><strong>Water Heater<\/strong><\/td>\n<td width=\"315\">4500-5500<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h2><strong>Amperes and Voltage<\/strong><\/h2>\n<p>If the wattage is not listed on the appliance, you can still estimate it by finding the current draw (in amperes) and multiplying that by the voltage used by the appliance.<\/p>\n<p>Most appliances in the United States use 120 volts. Larger appliances, such as clothes dryers and electric cooktops, use 240 volts. The amperes might be stamped on the unit in place of the wattage.<\/p>\n<p>If not, find an ammeter to measure the current flowing through it. You can obtain this type of ammeter in stores that sell electrical and electronic equipment.<\/p>\n<p>Take a reading while the device is running; this is the actual amount of current being used at that instant.<\/p>\n<p>&nbsp;<\/p>\n<h2><strong>Phantom Loads<\/strong><\/h2>\n<p>Also, note that many appliances continue to draw a small amount of power when they are switched \u201coff.\u201d<\/p>\n<p>These \u201cphantom loads\u201d occur in most appliances that use electricity, such as VCRs, televisions, stereos, computers, and kitchen appliances.<\/p>\n<p>Most phantom loads will increase the appliance\u2019s energy consumption by a few watts per hour. These loads can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance.<\/p>\n<p>&nbsp;<\/p>\n<p><em>Dr. Sarma Pisupati is a professor with the Department of Energy and Mineral Engineering, College of Earth and Mineral Sciences with <\/em><u>Pennsylvania State University<\/u><em>. Article extracted from <\/em><u>https:\/\/www.e-education.psu.edu\/egee102\/node\/1912<\/u><em>. <\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Interested in knowing how the energy use of appliances are calculated? Let\u2019s start with understanding power usage.<\/p>\n","protected":false},"author":464,"featured_media":25402,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[23083,23293],"tags":[405,1055,23172,23294],"class_list":{"0":"post-25448","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-electrical-fundamentals","8":"category-2023-summer","9":"tag-appliances","10":"tag-calculations-and-design","11":"tag-load-calculation","12":"tag-summer-2023"},"_links":{"self":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts\/25448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/users\/464"}],"replies":[{"embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/comments?post=25448"}],"version-history":[{"count":3,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts\/25448\/revisions"}],"predecessor-version":[{"id":25451,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts\/25448\/revisions\/25451"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/media\/25402"}],"wp:attachment":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/media?parent=25448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/categories?post=25448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/tags?post=25448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}