How to Conserve Energy at Home

By: Zolton Cohen

Conserving Energy in the Kitchen

In the winter, firing up a gas or electric oven or range contributes to the heat needed to keep the house warm. So, in addition to the smells of cooking food, you also receive the benefit of the extra heat from the oven and range top's burners or heating elements.

That heat is unwelcome in the summer. And if the home has air-conditioning, those systems are called upon to remove the heat and dump it outside the house. Therefore, during summertime, conventional cooking practices are doubly inefficient. First you generate heat you don't need or want, and then the A/C has to come on to remove it from the house.


For optimum energy efficiency, it makes sense in any season to use cooking appliances appropriate to the volume and type of food being cooked. Baking a few potatoes can be accomplished quickly and at much less energy cost in a microwave oven than they would require using a conventional oven. Countertop toaster ovens and broilers can prepare a wide variety of foods, and they don't produce the amount of heat or consume nearly the energy that a full-size range does.

When possible, cook foods together in the oven that require similar temperatures. And use lids on pots on the range top not only to prevent heat from escaping the top of the pot but also to reduce cooking time. An oven or rangetop burner can often be shut off before the food is completely cooked, and the food can be allowed to "coast" until it's ready, using the heat built up inside the pot or pan. If this prevents the oven's burner from firing up one last time, that's energy saved. Below are additional guidelines to help you conserve energy in the kitchen.

Proper Ventilation

Ventilation is important in a kitchen to remove cooking odors, humidity, heat, and combustion by-products from gas ranges and ovens. Most kitchens are outfitted with a hood or microwave over the range that comes with filters to strain grease and other pollutants out of the air. Some range hoods, however, do not vent directly to the outside of the house. So although they may filter some cooking grease and oil out of the air, they are ineffective in terms of removing heat, humidity, and combustion pollutants from the kitchen environment. An upgrade to a true outside-venting range hood can help remove cooking heat from the house, reducing the need for air-conditioning in the summer.

Prepare Big Batches of Food

In busy families it makes sense from a logistical and time-management point of view to make large batches of frequently eaten foods, like soups and spaghetti sauce, to be frozen for later use. Volume food processing like this also pays energy dividends. It takes much less energy to turn on the range once to cook a big pot of something rather than to turn it on multiple times to cook smaller portions.

Refrigerator Use

Refrigerators consume a relatively large portion of the household energy budget, but there are several simple things you can do to get the most bang for your refrigeration buck.

Just as combining driving trips in your car reduces the amount of gasoline your car guzzles, it makes sense to open the refrigerator door once to remove all the food you need at any one time. Opening the door repeatedly pulls cool air from within and causes the compressor to come on, making your electric meter spin. Anticipate what you're going to remove from the refrigerator, open it, remove what you need, and then quickly close it again.

It's also a good idea to allow warm foods to cool to room temperature before moving them to the refrigerator. That way energy won't be required to do work that can take place naturally. In the winter, leaving warm foods to cool outside of the refrigerator (if this can be safely accomplished from a food-safety standpoint) contributes a small amount of heat to the house.

Check Condensation Control Switch

Many people don't realize it, but most newer refrigerators incorporate small heating elements in their fronts. Why does a refrigerator need a heater? To prevent condensation in the area where the doors contact the front of the cabinet.

The narrow space between the upper freezer and lower refrigerator on conventional top-freezer refrigerators, and along the sides of those areas, are difficult to insulate adequately. As the compressor and refrigerant cool the interior of the fridge, some of the cold leaks out onto the steel cabinet enclosure. On a humid day, moisture in the air condenses on those cool surfaces just as it would on a cold beverage glass in the summer. When this happens repeatedly, mildew and mold can begin to form on the surface of the refrigerator in these areas, as well as on the vinyl door gaskets.

The solution to this problem is to insert tiny heating elements in the front of the refrigerator, just large enough to slightly warm those front surfaces to the point that condensation no longer forms. While the heaters don't draw a large amount of electricity, they're on constantly. That's fine in the summer when the feature is needed. But in the winter the heaters are not required in the generally drier indoor air, so that electricity is going to waste.

Refrigerators equipped with these condensation-prevention heaters contain a small control box, usually on the back wall. Alongside a switch in the control box might be a label that says "Prevents Condensation/Saves Energy -- On/Off." During the winter, simply moving that switch from the On to the Off position will shut down the heaters, thus saving electricity.

Don't Be Lazy When Washing Dishes

By hand: Washing dishes by hand is never high on anyone's list of favorite activities. Techniques for doing this mundane task, however, can save energy. Domestic water heating makes up nearly a quarter of the typical family's utility bill, but intelligent use of hot water while dishwashing can reduce that by a significant amount.

A surprising number of people attack the task of dishwashing by first opening the hot water faucet to its "full Niagara" position and then running dirty dishes in and out of the stream to first wash and then rinse. In the process of cleaning up after a meal they waste gallons of water -- and also the energy that heated that water.

A better way to wash dishes by hand is to close up the drain and run a couple of inches of hot water in the bottom of a sink, along with some liquid dish detergent. Then turn off the faucet. Wash glasses, cups, and silverware in this soap-concentrated water, and rinse off the soap over the same sink filled with water. The hot water used for rinsing runs into the sink, filling it up further for the larger items to come. And the soap used to wash these first items is retained as well.

Next stack plates in the soapy water and start washing them. Remove them as each is washed, and stack them in the bottom of the adjacent sink. When a good pile has accumulated, run water over the stack and remove and rinse each plate in turn. The water running from the plates as they are removed helps do a preliminary rinse on the next plate below, allowing it to do "double duty" on its way down the drain.

When everything has been washed, don't drain the wash water out of the sink yet. There are several gallons of hot water left in there -- water you paid to heat. Allowing it to cool off gradually adds some heat to the kitchen, which forestalls the furnace or boiler from coming on. In the summer you'll want to drain the hot water as quickly as possible in order to avoid adding its heat to the air-conditioning load.

: Newer dishwashers on the market are more energy efficient than earlier models, and they use less water for each load. But there are still some tricks for using them that can further decrease their water and energy use.

Newer dishwashers are equipped with sensors that determine how long the wash cycle runs in order to get dishes clean. The sensors detect food particles in the wash water. As long as the sensors "see" food particles in the wash water, the wash cycle will continue. Knowing that, the inclination is to rinse each dish nearly clean before putting it into the dishwasher. Bad idea.

Rinsing dishes under running water wastes water that you paid to heat. The dishwasher is going to use water to go through a cycle anyway, so let it do its job and clean the dishes the way it was designed. Rinsing the dishes before putting them into the dishwasher essentially consumes enough water to wash them twice. In addition, rinsing the dishes actually fools the internal sensors into believing that the wash cycle is nearly complete before it has had time to work. With few food particles to sense, the cycle goes almost immediately to rinse. The result can be dirty dishes once you open the door.

Modern dishwashers give you the option of using heat and a fan to dry the dishes. That heat is provided by an electrical coil in the bottom of the unit. Resistance heating coils like this require electricity, so shutting that feature off if you don't require instant drying will result in electrical energy savings.

The kitchen isn't the only room in your house that uses quantities of hot water. We'll learn about energy conservation in the bathroom and laundry room in the next section.