Kitchen
There’s a lot of technology in the modern kitchen: appliances, ventilation, hot water, and lighting. It’s a good place to start because there are many ways to save energy, and very few involve the HVAC system (which is the most challenging area to understand). The “energy tips” are separated by appliance, beginning with a selection of the kitchen overall. From the experts:
2.1 COOKING IN GENERAL
In the heat of the summer, cook and bake in the evening so the house has all night to cool off. Or just serve salad, fruit, and iced tea for supper.
Use only as much water in a pan as you need to cover what you’re cooking.
A warped or rounded pan that doesn’t make full contact with the stove burner element wastes most of that heat.
Match the pan to the burner size. A six-inch pan on an eight-inch burner wastes almost half of the energy.
Cut large items into smaller pieces, and they cook faster.
Use a double boiler for cooking vegetables (then to keep them warm).
Use lids to keep the heat in pans (unless a recipe advises you otherwise).
Place crockpots and portable pressure cookers outside in the summer to save on AC costs and to keep that humidity out of the house.
2.2 STOVETOP
When washing dishes by hand, fill one sink with an inch or two of soapy water and the other with rinse water. If you have a farmer’s sink (one big sink with no divider), use two plastic tubs.
Put a pan on the stove burner before turning it on.
Cooking with a high gas flame is the main reason why pans turn black on the bottom.
A solar kettle is a thermos-size bottle that you put on a windowsill. It uses direct sunlight to heat water up to boiling! It’s great for campers, or a free cup of hot java at a winter sports event.
Electric burners keep radiating heat for a few minutes after you turn them off.
Clean the burner pan—the metal bowl that sits under a burner to catch spills—because blackened burners absorb more heat. Keep them clean and shiny so they reflect heat upward toward the cookware.
2.3 SINK
You don’t need to rinse dishes before putting them in the dishwasher. Just scrape off any food and liquids. If you aren’t running the dishwasher right away, rinse dishes thoroughly (with cold water) so nothing cakes on.
If you wash dishes by hand using the two-tub method, well, newer dishwashers may use only two gallons of water. Can you do better than that?
Plug up the kitchen sink and open the hot water tap. By the time the water is good and hot, there are three gallons of water in the sink. That’s three gallons of water going down the drain.
In warm weather, rinse out pots and pans right away to cool them down so they don’t release heat and humidity into the house. Let them air cool in the winter when heat and moisture are beneficial.
Collect all that cold water that literally “goes down the drain” while waiting for hot water. Save it in a pot or bucket and use it to water plants, to change out the pet’s water (cats love fresh water), for ice cubes, to top off the aquarium, or toss it out the door into the yard, garden, or flowerbed.
2.4 MICROWAVE
The microwave is the most efficient way to reheat food and leftovers. It’s not suitable for thawing foods, however.
Microwaves are more efficient than a convection or conventional oven.
It doesn’t take nearly as much energy to reheat food as to cook it, so cook double portions and have leftovers.
Match the size of your oven to the job: full-size oven for a roast or turkey, microwave, or tabletop convection oven for smaller portions.
2.5 OVEN
Moisture or sweat on the oven door may indicate a tear or crack in the door gasket, which wastes a lot of energy from escaped heat.
Use glass or ceramic (versus metal) dishes in the oven. You can set the heat lower because they’re so efficient.
Turn the oven off ten minutes before it’s finished cooking.
Crack open a window when using a gas oven. Gas burners extract oxygen from the air as part of the combustion process.
Cook outside when you can. Keep all that heat, smoke, and grease out of the house. Many people like to barbeque outside. I deep-fry outside. All that vaporized grease doesn’t muck up the stove and the kitchen. It’s a great way to keep all that cooking heat out of the house and far away from the AC unit’s cooling coils.
Bake several items in the oven to save on per-item cooking costs.
Use a countertop toaster oven for small cooking jobs. Spend a little more for a quality unit with a timer and temperature control. My toaster oven browns better than the big, stove oven.
Use the self-cleaning feature on the oven right after you’ve cooked something in the oven because it’s already hot and doesn’t have to heat all the way from room temperature.
Don’t use the self-cleaning oven feature very often (it uses a lot of power), and run the exhaust fan when you do to exit any fumes.
I suppose the converse applies: cook in the oven after the self-cleaning cycle because it’s already hot.
Keep the oven preheat time to a bare minimum. You may not need to preheat at all, except with bread and pastries.
Self-cleaning ovens are more energy-efficient because they have more insulation in the back and sides (the self-clean mode gets very hot).
If you like to peek into the oven while cooking, get an oven with a window in the door and a light inside.
Convection ovens use 20 percent less energy than regular ovens because the air circulates continuously inside, and you get better heat distribution (and sometimes faster cooking time).
2.6 REFRIGERATOR
Defrost a freezer whenever there is more than ¼” of ice buildup. Turn off the freezer first, then place pots of hot water to loosen the ice. Don’t use anything sharp to scrape the ice off.
Allow at least one inch of space on all sides of a refrigerator or freezer for airflow.
Unclutter the top and sides (great spot to slide baking sheets or a pizza pan) of the refrigerator to allow air movement.
Freshness extenders absorb ethylene gas in the crisp drawer to keep fruit and vegetables fresh longer and cut down on waste.
Recycle your old refrigerator. (They’ll probably put a new, efficient compressor in, refurbish all the gaskets—hey, why not do that stuff and keep it for a few more years?)
Label items in storage containers in the fridge so you don’t have to stand there with the door open to find what you’re looking for.
Cover foods, and especially liquids, placed in the refrigerator to keep the moisture in. It’s better for the foods, and the refrigerator doesn’t have to work extra hard to extract that humidity from the air.
Many refrigerators have a small heater built into the outer walls to keep moisture from condensing. See if you can turn that feature off via an energy- or power-saving switch. Keep an eye out if you do, in case there’s condensation.
If your refrigerator is near a heat source—sunlight, the stove, the dishwasher— boost efficiency by relocating the fridge to a cool, shady location.
It’s usually less expensive to buy one big refrigerator than to keep your old one for extra storage and buy a second, smaller fridge because the old one is probably a real energy hog.
Set the refrigerator and freezer at recommended temperature settings: 40°F and 0°F, respectively.
Clean the gasket in the fridge door. Gummy jam or foodstuffs can stick so much they rip the gasket off the door.
Clean dust and lint out of the air-grill on the bottom of the refrigerator. Pull the unit out once a year to dust off the metal heat-exchange grid and fan blades (if they’re accessible) at the back.
Tiny drain holes inside the fridge can get plugged. When you open the fridge door, moisture condenses on inside surfaces, and then drains to a pan at the bottom of the unit (then evaporates into the house). If the drain holes are plugged, the condensate stagnates inside the fridge.
2.7 FREEZER
A manual defrost refrigerator uses half the energy of an automatic defrost model. Defrost frozen foods in the refrigerator before cooking them.
A full freezer performs better than an empty one. If necessary, fill containers with water and freeze them. When the power goes out, that ice keeps everything cool.
Ice built-up on the coils inside a freezer makes it work harder to keep setpoint temperature. If you live in a humid climate, icing happens faster as the moisture condenses out of the air.
2.8 DISHWASHER
Skip the “pre-wash” cycle on the dishwasher and use the economy cycle instead.
Dishwashers have built-in water heaters to increase the temperature to 140145° F, so it’s okay if you set the water heater to a lower temperature.
The dishwasher uses the same amount of energy no matter how many dishes there are in the load. Rinse off dishes (with cold water) until you have a full load to run.
Pots and pans go on the top dishwasher rack, so they don’t block full waterspray flow everywhere. Otherwise, fill the racks to optimize energy and hot water use (per the manufacturer’s recommendations).
“No heat” drying in the dishwasher saves about 7 percent of the energy.
Match your dishwasher cycle to the load. For example, “light wash” dishes that have been rinsed off in the sink already.
Gallons of water used per cycle:
- Eight for pots and pans
- Five for normal cycle
- Three for light and china
Older dishwashers use eight to fourteen gallons of water. Newer models use six and a half gallons, down to as little as one and a half gallons. Don’t worry, even with a paucity of water, they clean very well.
Don’t block the vertical airflow path in the oven. No foil on the racks, and stagger multiple pans on different shelves. The food cooks faster and more uniformly when air circulates freely.
2.9 STOVE VENT HOOD
Run the vent hood not just to exhaust smoke and cooking odors but humidity. In the summer, the AC has to extract that moisture from the house air.
The exhaust flow should go outside, not into the attic.
A multi- or variable-speed stove vent hood fan lets you match the exhaust rate (and fan noise) to the needs: to purge smoke, odors, steam, and fumes at different rates.
Wash the kitchen vent hood filter. Standard stove vent hoods draw exhaust air through a wire-mesh filter. Grease condenses out of the airflow and collects in the wire mesh. Pull the filter out periodically and run hot water through it to melt away the oil and grease.
Some cook surfaces have a downdraft exhaust (a grate in the middle of the stovetop that sucks air down through the stove). That kind of exhaust method draws several times more air than updraft exhaust fans (in a vent hood above the stove) because hot air rises naturally, helping with the exhaust flow.
2.10 GARBAGE DISPOSAL
Put fresh produce waste in a compost pile for some great mulch in the spring.
Grind a fistful of ice cubs every month in the garbage disposal to sharpen the blades and clean up the interior surfaces.
Cooking is all about heat, mostly boiling water. A little bit of science helps to understand how and why some of the above energy-saving techniques work. Also, if you know the why you won’t have to remember all the individual energy tips.
2.11 THE THERMODYNAMICS OF WATER
It takes one calorie of heat to raise the temperature of one gram of water 1°C. You need eighty calories of heat (the “latent heat of fusion”) to melt one gram of ice into water at 32°F. It takes 530 calories of heat (the latent heat of vaporization) to change one gram of 100°C water (boiling) into 100°C steam. Note: the same quantity of heat extracted drives these processes in the opposite direction, toward freezing.
Starting with ice at 0° C
- + 80 calories to melt
- + 100 calories to boiling
- + 530 calories to steam
Note: Food calories are actually “kilocalories” or 1000 heat calories.
2.12 DON’T STAND IN THE FREEZER DOOR.
Heat entering the freezer causes ice to melt. Every gram of melted ice sucks eighty heat calories out of the fridge. After you close the door, the freezer must add another eighty calories of heat to turn that water back into ice. By the time the freezer has reached equilibrium again, you’ve wasted enough energy to bring two grams of water from 0°C to 80°C – almost boiling!
2.13 KEEP A FIRE EXTINGUISHER HANDY.
If you get a fire on the stove, the first reaction is to throw water on it. Electric burners? Water! So not good. Class C fire extinguishers are rated for electrical fires. Keep a fire extinguisher a step or two away from the stove. Know how to use it.
Check it yearly to be sure it’s in good working order.
2.14 PUT A LID ON IT.
A covered pot comes to a boil faster than without a lid. It takes 530 calories/gram to create that steam, calories that come from the water. If you trap the steam inside, pressure builds up and less heat escapes from the system through evaporation.
2.15 USE A PRESSURE COOKER FOR HIGH–ELEVATION COOKING.
A pressure cooker has a tight-fitting lid that traps steam inside. On a higher setting, at a pressure of 15 psi (your auto tires, by comparison, are at 40 psi), the boiling point rises from 212°F to 250°F. Everything cooks faster, using less energy.
2.16 WATER BOILS FASTER AT HIGHER ELEVATIONS.
At sea level, water boils at 212°F. For each increase in five hundred feet of elevation, the boiling point of water drops by 1°F. At 7,500 feet, water boils at 198°F. So, the same pot of water on the same burner setting comes to a boil faster. That saves energy, except the food must be cooked longer at the lower temperature.
2.17 WATER CAN’T GET HOTTER THAN BOILING.
Turn the burner down once you get a rolling boil going. Simmering with a few bubbles is just as hot as a furious boil and uses less energy. Note: first, reach a good boil before dropping back to simmer to be sure you’re at 212° F.
2.18 STEAM YOUR VEGETABLES.
The less water you use to cook your vegetables, the less energy required to bring the water to a boil. A steamer basket inside a pot needs less water than a pot full of water. You also don’t lose all the minerals to the water. A pressure cooker uses even less water than a steamer—and gets the job done faster.
2.19 A POT FULL OF BOILING WATER KEEPS ON COOKING AFTER YOU TURN THE HEAT OFF.
If you cover a pot (to keep from losing heat through evaporation), it won’t drop in temperature very much for quite a while. The thicker the pan (cast iron versus stainless steel) and the greater the contents, the more heat it retains. Burners on electric stoves retain their heat for some time. Gas burners, not so much.
2.20 HOT AIR RISES.
The air inside an oven at 450°F rises very fast. So fast that when you open the oven door to check out your cake, the oven temperature can drop by 10°F. As soon as you close the door, you’ll see the heating element turn red to heat the oven back to the setpoint temperature. You not only have to heat the oven all over again, all that escaped heat becomes a load on the AC system in the summer.
2.21 PUT A NAIL INSIDE BAKING POTATOES.
Have you seen aluminum “potato nails” advertised online to cook potatoes faster? Steel nails have a high thermal conductivity; aluminum is even better! That nail sticking out of the spud conducts heat into the middle and cooks it from the inside, too. Be sure to punch holes in the potato skin with a fork halfway through the baking time. Otherwise, the pressure builds up inside the skin, and the potato might explode. Talk about pressure-cooking!
2.22 MUST–HAVE KITCHEN APPLIANCES.
Do you really need that electric can opener, food processor, electric grill, slow cooker, electric fryer, electric rice cooker, ice cream maker, electric tomato strainer, electric bread maker, electric food mill, espresso machine, milk frother, electric juicer, air fryer, dehydrator, and that electric immersion cooker? Dare I suggest to sweep the kitchen with a broom instead of vacuuming?
2.23 COOK SEVERAL ITEMS AS LONG AS THE OVEN IS HOT to reduce the energy used per dish. I keep several baked potatoes in the fridge for leftovers. (Cooked potatoes that have been in the refrigerator overnight have three times the resistant starch, which is very healthy.)
2.24 USE THE STOVETOP VENT.
All the steam from cooking adds heat and moisture to the air in your kitchen. In the summer, the HVAC system has to remove moisture from the air. The vent hood removes it, too, along with the grease, smoke, and odors. I purchased an older house a while back. The kitchen ceiling was yellow with grease! That’s where oil from the frying pan ends up if the stove vent hood isn’t ducted outside.
2.25 THE STOVE VENT HOOD SHOULD SEND THE EXHAUST OUTSIDE.
Kitchen vent-hood air should go out the back wall directly outside or up a flue and out the roof. The kitchen exhaust should not go into the attic. Grease building up inside the attic—a fire hazard! Not to mention odors and moisture and all the mischief they can cause.
2.26 LEFTOVERS WERE THE ORIGINAL FAST FOOD.
What can be more energy-efficient than cooking up a batch of baked potatoes and tossing them in the fridge? Now you have fixings for hashed browns, microwave baked potatoes, potato cakes, and potato salad—healthy snacks! Ditto for a batch of spaghetti sauce. People buy sauce in big jars all the time and refrigerate leftovers; what’s wrong with chilling your homemade recipe? Warm-up smaller portions in the microwave or a toaster convection oven.
2.27 CRACK OPEN A WINDOW WHEN YOU RUN THE STOVE VENT FAN.
When you run the exhaust vent over the stove, it sucks a lot of air out of the kitchen. The central HVAC has long since dehumidified, cooled, and/or heated that air. And now all that conditioned air is going outside? If you crack open a kitchen window an inch or two while the exhaust fan is running, most of the “makeup air” comes from outside.
2.28 DON’T STAND IN THE REFRIGERATOR DOOR.
There’s a reason why refrigerators have crisper drawers for fruit and vegetables. They isolate fresh produce from the dry air in the fridge. (Otherwise, the produce desiccates quickly.) When you stand in the door trying to decide what you need, hot and humid air gets into the fridge, and cold, dry air escapes. Once you close the door, the system must cool down and dehumidify that air.
2.29 AIR–DRY DISHES IN THE DISHWASHER.
Before you read this book, you’d think: great idea! Now, hopefully, you wonder: what about all the humidity you’re dumping in the air? Although: Unless the dishwasher has a dedicated air vent to blow air outside (they don’t, but maybe they should, at least in the cooling months), all that moisture ends up in the house.
2.30 MIND THE FRIDGE.
Older refrigerators have the cooling coils on the back. Those cooling elements collect a lot of dust and grime. Wipe them off so their heat-transfer properties are optimal. Those coils depend on airflow to transfer heat away from the refrigerant. Suppose the coils are crammed up against a wall. Or the space behind the fridge is covered up with baking trays. Or a stack of tablecloths. How’s the heat going to escape?
2.31 KP DUTY.
It takes the same amount of electricity and hot water every time you run the dishwasher. It’s more energy-efficient to run a full load. If it takes a couple of meals to fill up the dishwasher, rinse the dishes and utensils and stow them in the dishwasher.
2.32 BROWN BAGGING IT.
Whatever happened to brown-paper grocery bags? Now they make you ask for one, as if it’s a real imposition. You can fit more in one brown paper bag than six plastic bags. A brown bag decomposes in months; a plastic bag takes twenty years (plastic bottles take 450 years!) Instead of asking, “Do you want your milk in a bag?” the grocery store clerks should ask, “Paper or plastic?” Or maybe, “Do you want to help the environment or destroy it?”
2.33 RUSTY VEGETABLES.
An enormous amount of fresh produce is wasted every year in America – close to 50 percent. When the California growing season ends, our produce comes from Mexico and points further south. Just imagine all the fuel wasted transporting that produce to your neighborhood grocery store. Thrown away, all of it (well, half of it). Try planning your fresh-produce purchases better, or toss the droopy stuff in a blender for a health-drink juicer. If you live in the suburbs, make a compost pile.
2.34 RUBBER STOVETOP UTENSILS.
There’s something creepy about non-stick pots and pans—spoons, spatulas! I can see why nobody cooks at home anymore: rubber chicken, rubber eggs, rubber bacon. It’s all but impossible to find non non-stick pots or pans. Fortunately, I still have Mom’s old pots and pans from twenty-five years ago. They still cook just fine.
2.35 EAT AT HOME MORE OFTEN.
I know people who eat fast food three meals a day. What a waste of good money, gasoline, time—health! Personally, I eat out maybe three times a year to celebrate one thing or another. I’m no gourmet cook, but 92 percent of the stuff I cook at home is better than any restaurant fare.
2.36 CRISPY CRITTERS.
Can somebody please invent a smartphone app that tells you if an apple is crisp and yummy and not bright and shiny outside but mushy inside? What happens to all the produce they don’t sell? I hope bananas go to a baby-food factory, apples to applesauce heaven, and veggies to the frozen mixed-vegetable farm.
2.37 THE CHILLING TRUTH.
Got something to thaw out for supper? Instead of putting it in the kitchen sink, let it thaw inside the refrigerator. That way, you don’t lose all the cold but transfer it to items in the fridge. Conversely, if you have a hot item you just finished cooking and you’ll be storing a portion in the fridge for leftovers, allow it to cool down before you put it in the freezer or refrigerator.
2.38 REFRIGERATOR STRATEGY.
Instead of opening the fridge several times preparing a meal, why not take out everything you need at once, fix your meal, open the door one more time, and put it all back.
Future Tech!
2.39 A SMART REFRIGERATOR OPERATES JUST LIKE YOUR AC.
It extracts heat out of the fridge and sends it into your house! That’s fine in the winter, but the summer? You spend electricity to (1) cool down the refrigerator and then (2) take the fridge’s (exhausting) heat out of the house. There should be a way to vent all that heat outside.
2.40 REFRIGERATORS WITH A SEPARATE CONDENSING UNIT.
They make mini-split HVAC systems (the fan is in one room and the condensing unit is outside). Why not a mini-split refrigerator? Who wouldn’t like to relocate all that refrigerator-fan and condenser-motor noise outside? Restaurants have large walk-in refrigerators and freezers with a condenser outside. Who’s going to market a similar product for homes? Never happen.
2.41 NO MORE PLANNED OBSOLESCENCE.
If your fridge goes kaput, you won’t have to buy a whole new unit, but just a new condensing unit (like when your HVAC dies, you rarely have to purchase a new air handler inside, just the outside compressor unit). Down goes corporate profit margins and stop prices if refrigerators last so long they become heirlooms.
2.42 THE “EPUCK” is a hockey-puck-sized contraption that takes the heat from the coffee cup you sit on top, and converts it into 12-volt power to charge a smartphone via a USB port.
2.43 That wide, flat space on larger stovetops between the burners? Turn it into a big ePuck device, where you sit pots and pans after the cooking is done, to use all that otherwise wasted heat to charge up a 12-volt battery.