By James Dulley, Published September 25 2009
Time of year plays role in appliance decisionsDear Jim: My wife tells me it is more energy efficient to use small cooking appliances instead of the electric range, but I prefer the range. How do I determine how much it costs to use various kitchen appliances? – Richard W.
Dear Richard: The electric range, oven, refrigerator, and dishwasher are the primary electricity consumers in most kitchens. Many times, using smaller countertop kitchen appliances can result in less electricity usage overall, but not always. Many factors, including the time of the year and your HVAC (heating, ventilation, air-conditioning) system determine this overall electricity usage.
For example, if you use the kitchen range during the winter, all of the electricity used for cooking ends up heating your house and reducing the heating load on your furnace so it is not all wasted. The drawback is the heat from a range is basically resistance heating which is very expensive. Heat produced from a gas or oil furnace or a heat pump costs much less.
During the summer, things are reversed. If you air-condition your house, the heat from cooking makes the air conditioner run longer so the costs of cooking is effectively increased. The moisture given off from cooking also increases the air-conditioning load.
It is simple to determine how much an electric appliance costs to use. The nameplate on an appliance lists the wattage or amperage it consumes. Multiply the wattage by the amount of time (in hours per use, per week, or per month) it is used and then divide this by 1000. This gives you the kilowatt-hours used. Multiply this number by your electric rate in dollars per kilowatt-hour. If the nameplate lists amperage, multiply it by 120 to get watts.
Large quantities of food are usually most efficiently cooked on the range or in the oven. Most newer self-cleaning ovens have heavy wall insulation so they bake and roast efficiently. A good rule of thumb is to use the smallest cooking appliance possible for the amount of food. For just cooking a couple of hamburgers, a countertop toaster oven is ideal. If the quantity of burgers requires you to cook them only several at a time, choose the large range oven.
Another consideration is how many consecutive items you have to cook. If you are going to bake a cake, roast meat and then bake potatoes, use the large range oven. The mass of the oven holds heat from one food item to the next. This eliminates the preheat cycle and provides even cooking. Using a high-quality slow cooker, such as a Crock-Pot Trio, can also be an energy saver. For fast cooking, a pressure cooker dramatically reduces cooking time.
A small countertop convection oven is efficient. The convection oven has a small fan to circulate the heated air around the food to cook it faster. Reducing cooking time reduces the total kilowatt-hours consumed and the heat generated in your kitchen.
Some foods cook better without the convection air, but they will take longer. Of course, using a microwave oven saves electricity because the cooking times for small quantities are very short.
Dear Jim: During mild weather, I use ceiling paddle fans and have them in most of the rooms. I have been told to keep them all running for the best cooling. Is this the correct way to use them efficiently? – Jim C.
Dear Jim: What you have heard it not correct. Ceiling fans do not cool the air at all. They make you feel cooler by creating a breeze over your skin. This breeze increase the heat loss and moisture evaporation from your skin. Both make you feel cooler.
The electricity a ceiling fan uses ends up as heat in the air so running one actually makes the room slightly warmer. If you are not in the room to feel the breeze, running one just wastes electricity.
Send inquiries to James Dulley, The Forum of Fargo-Moorhead, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.dulley.com