Luxury in the Kitchen

Style Meets Performance in Next Generation Appliances

Fueled by interest in nutrition and healthy living as well as the celebrity status of chefs and popularity of lifestyle television programming, cooking has been upgraded from mere preparation of food to a creative and often social activity. As a result, kitchens have taken center stage in the home, combining design and appliances that are sophisticated, convenient, and time saving, and in many instances mirroring the sleek, practical aesthetic of the professional kitchen.

In a new home, the kitchen is often a key selling point. In an existing home it's the space most regularly revamped in order to obtain the latest systems, cabinetry and appliances. According to Oregon-based CNW Research, which has studied U.S. consumer spending for more than a decade, kitchens are at the top of the list in consumer home remodels, and consume more attention, energy, finances and complex decision-making than any other home project.

Consumer expectations for kitchens and appliances are continually evolving. Among the consumer lifestyle trends for 2010 revealed at this year's International Home + Housewares Show are the Wellness Kitchen, driven by the desire for maximized nutrition and purified air and water, the Green Kitchen, and Cooking for Fun, which recognizes the preferences of cooking enthusiasts.

Manufacturers are meeting heightened awareness and enjoyment of all things culinary with elegant, high tech appliances that enhance the experience and bring gourmet results home. This article will explore new trends and technologies in residential kitchen refrigeration and cooking, focusing on features that offer added flexibility, improved performance, better food safety and environmental responsibility.

Photo courtesy of Thermador

Modular Refrigeration

Introduced in the 1990s, modular refrigeration is a popular trend in residential kitchens. The term modular refrigeration refers to stand alone, independent refrigerated units that are available as fresh food, freezer or wine preservation columns of varying widths, generally between 18 and 36 inches. They provide considerable design flexibility, giving architects the option to forego the often cumbersome refrigerator-freezer combination in favor of two or more refrigeration columns of any size and configuration and serving different functions. The units offer multiple design and installation possibilities, and can be placed wherever they are needed − separately or side by side − for a kitchen customized according to a preferred workflow. Some users, say, may select a cook's refrigerator for unprepared items near the stove and one closer to dining room for beverages and condiments, while another may want a freezer column containing meats next to the oven and a column for fresh food next to the sink to facilitate vegetable preparation. Refrigeration is moving out of the kitchen too, as consumers opt to place products where they are going to use them − a wine storage unit in a family room or refrigeration in an outdoor entertaining space.

Modular refrigeration enables design flexibility in the kitchen. Photo courtesy of Thermador

 

In addition to liberating the kitchen from the hegemony of the monolithic fridge/freezer combination, modular refrigeration has been well received because of the way it looks and performs.

Aesthetics

With the more streamlined look in kitchens, large appliances are following suit, being disguised and integrated into the overall décor. While stainless steel finishes are still popular, the predominant design trend today in home refrigeration is to go one step beyond integration to true flush mount refrigeration where the unit "disappears" into the kitchen cabinetry for a cleaner, ultra modern look.

Modular refrigeration harkens back to German engineering, and the Kuhlschrank, which literally means 'cool cabinet. "It's a cabinet with a compressor and the cabinet gets cold. Because modular units are more a part of the cabinetry than an appliance, they represent a paradigm shift in the way design professionals think about refrigeration and configuring the kitchen.

Temperature and humidity controlled compartments keep food fresher longer. Photo courtesy of Thermador

Food Chilling and Storage Performance

Each modular refrigeration column operates with its own motor and compressor, eliminating air exchange between the refrigerator and freezer compartments − often the source of odor and/or flavor transfer. Air temperature is also more evenly distributed and humidity levels are appropriate for vegetables and fruits to stay crisp and fresh longer. To achieve equal temperature levels on all shelves, multi-flow air systems provide a continuous flow of air running along the interior back wall. Cold air channels behind the door racks ensure that food items on these racks are stored at the same temperature as in the refrigerator compartment.

Many models have individual temperature- and humiditycontrolled compartments to achieve longer food storage for specific items, such as fish which should be stored at 32 degrees F, meat and poultry at 33 degrees F, and produce at 35 degrees F. Zoned sensors respond to food temperatures in these different sections and trigger adjustments to keep temperature consistent within 1.5 degrees F.

Express chill and freeze buttons have also become standard features on today's modular units: When warm food is added to the refrigerator or freezer, the unit quickly returns to the proper temperature, as sensors override the current selection, temporarily pushing the unit into maximum cooling mode.

Convenience Factors

Refrigerator interiors are designed for practicality. Spill-proof glass shelves facilitate easy cleanup. Door shelves are adjustable, freezer columns accommodate extra tall items and gallon door storage reflects consumer preferences of economical family-size purchases. At the touch of a button motorized shelves raise and lower to accommodate items of various heights, even when they're fully loaded with up to 22 pounds of food.

Water and Ice Dispensers. Over the years, manufacturers have improved their ice and water dispensers and today's models have capabilities such as measured dispensing and rapid filling such that an 8-ounce glass can be filled in 8 seconds. Anti-clump systems agitate ice at timed intervals to keep it from freezing together after defrost cycles or extended door openings. Through-the-door systems allow easy access to water, ice cubes and crushed ice without having to open the refrigerator cabinet. Large flexible dispensers with pulldown pitcher flaps allow the use of extra tall or wide containers.

Water dispensers almost always include water filtration capabilities. Carbon is primarily used in refrigerator filtration because of its ability to absorb chemicals and impurities that diminish the taste and smell of the water. Filtration systems vary according to brand, though most are carbononly or a combination of carbon and a fiber filter to catch rust, lead and other sediments found in water. Filters should be changed as specified by the manufacturer or at least every six months to ensure continued water quality and keep contaminants trapped by the filter from leaking back into the water. While refrigerator ice and water dispensers do increase energy usage, they can offer a healthier alternative to bottled water at a fraction of the price and without the health risk of drinking from plastic containers. An additional benefit is the fact that many refrigerator water filters also retain fluoride, which is usually not found in bottled water.

No-Frost Systems. Virtually all modular refrigeration systems use adaptive defrost control systems that defrost only when it's needed, which saves energy and eliminates freezer burn. Sensors electronically calculate the amount of time needed in between Lighting. Refrigerator lighting is getting more energy efficient. Replacing the formerly ubiquitous incandescent light bulb scheduled for phase out in the U.S., Europe, Canada and other locations, the refrigeration industry has turned to LED, and halogen lights. Of the two, the halogen light spectrum is considered to display the true color and texture−and thus condition−of foods. A typical lighting scheme may include two upper halogen spotlights and two halogen wall towers to illuminate food evenly, so even foods at the back can be easily seen and don't languish out of sight as the expiration date passes. LED lights may be slightly less expensive to operate, but they cast an unattractive bluish light on foods.

Quiet Operation. The compressor keeps the refrigerator cool. A standard compressor circulates cool air on a set cycle. But at the heart of quiet operation is a variable speed compressor, which keeps running at very slow revolutions per minute, and cycles up only when necessary to maintain the temperature of the products inside the cabinet. Some companies even insulate the compressor in higher end models.

Greater Capacity. Manufacturers are continually working to gain extra capacity within the same footprint. One way of doing this is through more effective insulation technology. Proprietary vacuum panels reduce the thickness of refrigerator walls, and thinner walls mean more room inside. A partial vacuum is created within the panel walls and filled with a low conductivity substance such as powder, fiber or aerogel. Increased energy efficiency is another byproduct as heat gain in the refrigerator is reduced, thereby reducing the energy required to maintain lower temperatures within.

Environmental and Energy Considerations

Refrigerators are moving toward more positive environmental and energy performance.

Refrigerants. There has been a movement toward a new generation of environmentally friendly refrigerants. Hydrofluorocarbons (HFC), a group of compounds containing carbon, fluorine and hydrogen, but not chlorine, have replaced chlorine-containing chlorofluorocarbons CFCs and hydrochlorofluorocarbons (HCFC). HFCs, however, are not an ideal solution as they have a global warming impact. Major HFC releases occur during their manufacture, from filling refrigeration equipment and from refrigerators' end-of-life deterioration.

Other substances being tested as an alternative to HFCs are greenhouse-neutral hydrocarbons such as propane and isobutane, which are extensively used in European and Asian refrigerators. The drawbacks are that these substances carry slight flammability concerns and are currently not UL approved or sanctioned by building codes in many municipalities.

Energy Efficiency.A refrigerator runs 24/7, and in a typical home, generates 8 percent of the total annual energy expense, according to 2005 data from the U.S. Department of Energy. Compared to the 1970s, when a new refrigerator averaged 1,800 kilowatt-hours (kWh) per year, the best of today's versions log in only about 500 kWh annually. Recent improvements in insulation and compressors have cut some of the fat out of energy usage. Variable speed compressors, for example, save energy by operating at ultra slow revolutions per minute rather than shutting off and turning on again, which expends energy unnecessarily. Refrigerators and freezers with individual compressors generate only the energy required to keep their own compartment properly chilled. Adaptive defrost systems operate only when needed, and there are settings to adjust temperatures for low food levels, to disable ice making and lighting when users are on vacation and to function in Sabbath mode, meaning that lights, fans, sounds, alarms, compressors or other electrical activity is disabled when the refrigerator door is opened without affecting its operation.

Flush-mounted refrigeration is a top trend in kitchen design. Photo courtesy of Thermador

All refrigerators sold in the United States are required to meet the Department of Energy's efficiency standards, and many meet the department's more stringent Energy Star qualifications as well. A new refrigerator with an ENERGY STAR label is required to use at least 20 percent less energy than stipulated by current federal standards. Today's Energy Star rated refrigerators use about half the energy of those manufactured prior to the early 1990s. Through its rating system of appliances, the program claims to have helped save enough energy in 2008 alone to avoid greenhouse gas emissions equivalent to those from 29 million cars − all while saving consumers $19 billion in utilitly costs. However, when it comes to free standing refirgerator ratings, the Energy Star program is not without its critics. Detractors decry the lack of independent auditors − manufacturers supply data on their own products − and contend that the energy efficiency bar is set too low, with too many products qualifying for the star to make it meaningful. For built-in refrigerators, Energy Star criteria are more rigorous. The built-in installation makes the heat exchange to the outside more difficult than freestanding units, and the air inlet and air outlet for cooling air are more restricted in the built-in installation. In addition, outside dimensions are fixed due to the built-in cabinet and so with a given interior volume, more insulation can not be added than the outside dimensions allow. Freestanding units have more tolerance.

Today's kitchens feature sophisticated cooktops, built-in ovens and warming drawers. Photo courtesy of Thermador

Installation

When it comes to installation, slimmer modular units are far easier to move and install than conventional refrigerators that can weigh up to 800 pounds.

One complaint of design professionals used to be the complicated installation, but the industry has responded with prepackaged and labeled parts to simplify the procedure. Still, cabinet preparation is crucial to a smooth installation. With modular refrigerators, the intent is that any standard size kitchen cabinet can be replaced by a modular column, with a gap between two tall cabinets the ideal scenario. Units should have hinges that can open to 115 degrees to allow the columns to be fully flush mounted without sacrificing accessibility. Hinges should also be heavy duty, and be able to support more than 200 pounds of door weight, particularly if custom wood panels are used. For complete installation details, the product's spec sheet should be consulted. Installers familiar with flush-mounted modular units should be used, as there is a learning curve experienced by non-cabinet installers.

Cooking Appliances

Cooking is the application of heat to food. Indoor cooking is almost entirely done either in an oven or on a cooktop, and is broadly divided into gas and electric types. Consumers are interested in appliances that deliver gourmet results, maximum nutrition with time savings at the right price points. There are no Energy Star ratings applicable to cooking appliances, though manufacturers do consider energy efficiency a competitive advantage, and are the prime movers in the new designs, materials and processes that will boost energy efficiency while reducing embodied energy over the life cycle of the product.

Design Flexibility with Cooktops

Because they can be installed on an island or other location with ample counter space, cooktops afford design flexibility. Consumers appreciate their modularity, which allows placement of interchangeable elements including griddles, steamers, woks, rotisseries, and deep fryers that can be switched at will. Many cooktops also incorporate smart features that can select proper cooking times and temperatures for various foods. Offered in gas, electric, and dual fuel and in ceramic glass, porcelaincoated steel, or stainless steel today's cooktops may be designed with integrated downdraft ventilation, varying burner placement, and front or side controls. For serious cooks, the space between burners, grate size, and configuration are important factors. For example, those who routinely cook with large pots and pans would do better with four widely spaced burners than five or six crowded together.

The design of a star burner offers greater heat coverage, and a smaller cold spot, making it ideal for any pan size.

Gas. Gas cooktops are the choice of many serious cooks. Gas burners produce heat instantly, and can be easily controlled to change the flame quickly between low and high heat. When gas burners are turned off, the heat stops and so does the cooking. Improving on the traditional gas ring burner are star-shaped burners that distribute heat more evenly from the center of the pan to its edges. The perimeter of a star-shaped burner can be up to 56 percent greater than a round burner of the same diameter, which allows for more flame ports and thus better flame spread and reduced cold spots. With star burners boil times are faster too, with a range of from over 24 minutes to 12 minutes and 40 seconds to boil four quarts of water.

When specifying a gas cooktop, the BTU output is a prime consideration − both maximum and minimum levels. One of today's biggest cooking trends is professional-style stoves for the home, with burners that boast large BTU outputs. But burners that put out high BTUs have large holes, or ports, to dispense the flames − and those holes are often too big to maintain combustion when turned down to simmer. Manufacturers have sought to overcome this challenge by burner-within-a-burner system or placing smaller burners that can cycle on and off at a low flame alongside the higher BTU burners. Users who want the widest range of cooking options will want star-shaped burners with both high and low BTU output (200 BTU/hour to 18,000 BTU/ hour is about the extent of the range), with simmer systems to control temperature via electronics that cycle the burner on and off to maintain temperatures as low as 100 degrees F that can simmer delicate sauces or keep food warm without scorching and the need for constant stirring.

The New American Home 2010: A Sign of the Times

This year's version of the New American Home, a 6,000-square-foot desert contemporary designed by the KTGY Group of Irvine, California, is much smaller than recent versions. It is being built to National Association of Home Builder's (NAHB) Green Building Standard and will meet the U.S. Department of Energy's Builders Challenge and Energy Star energy efficiency programs. The kitchen reflects a return to the simple pleasure of cooking with an expansive open plan and appliances that help home chefs achieve gourmet results. Multiple built-in wall ovens including an electronic thermostat to monitor temperature, a 6-burner gas range top with star-shaped burners and intermittent flame simmer features, and a warming drawer were selected for cooking. Modular refrigeration columns were chosen to support consumer work flow. For more than 25 years, the NAHB's New American Home has showcased practical new ideas in the context of prevailing popular taste. This year's home is located outside of Las Vegas and can be viewed during the International Builder's Show held in that city from January 19-22, 2010.

Appliances at the New American Home help home cooks achieve gourmet results. Photo courtesy of Thermador

The sealed vs open burner is another consideration. Both versions have their proponents. In an open burner system, as most restaurant ranges are, the spills and boilovers end up on a pan below the surface of the burners that must be taken out and cleaned. Sealed burners were developed to facilitate cleaning, as the spills are capture in the spill-trays and can be mopped up on the surface, though both the grate and caps may require cleaning too. When it comes to cooking, some users feel that open burners offer better flame quality and distribution, citing the amount of "supply air." The ports need supply air to burn effectively, yet in a sealed burner, the ports are close to the pan, causing the flame to seem cooler or less aggressive, than with an open system. In this instance sealed star-shaped burners may come out ahead in combining cleaning convenience of a sealed burner with the heat distribution of the star shape. Star-shaped burners that are raised off the surface of the cooktop on a pedestal further facilitate cleaning, as a sponge can comfortably fit underneath the burner.

Electric. Traditional electric cooktops with electric coils are the least expensive cooktop option. Coil burners heat up slowly, change temperature slowly, and cool slowly, continuing to cook food even after the burner is turned off. Traditionally electric burners have lagged their gas counterparts in heat control, though manufacturers are quickly changing that with improved response and control features for electric cooktops.

Today, the most popular style of electric cooktop is the ceramic-glass "smoothtop."

Glass and ceramic are processed and tempered to conduct heat from the element through the stove top into the pot. While glassceramic is a mechanically strong material and can sustain repeated and quick temperature changes, it has a very low heat conduction coefficient and unlike metal cooktops, glass tops generate heat only at the element site, so surrounding areas remain cool to the touch.

Until recently, the elements used under the glass tops were similar to coil-type burners. Advances in technology have significantly upped the opportunity to use more convenient, energy-efficient heat sources, with glass stove tops now utilizing one of three sources of heat: radiant ribbon, quartz halogen or magnetic induction. Radiant ribbon is similar to the standard coils in regular stove tops and while having the same mass as an electric burner has considerably more surface area, which means it heats up faster and more efficiently coming to full temperature in as little as five seconds. Radiant ribbon can be used as the sole source of heat or combined with the quartz halogen or the magnetic induction elements. Quartz halogen is the quickest to heat up but the longest to cool off. Magnetic induction is the most energy-efficient heat source.

Induction Cooktops. Induction technology has been around for more than three decades and in extensive use in Europe and Japan as well as by professional chefs in the U.S. Induction cooking uses the transfer of magnetic energy, rather than flames or electric elements, to generate heat. Under each "burner" is a coil of copper. When an electrical current is passed through this coil, it creates electromagnetic energy. The energy passes into the pan, where the iron molecules vibrate up to 50,000 times per second, with the friction between the molecules creating the heat. As the heat is produced within the cooking vessel itself, cookware must have some iron content on the bottom in order to react with the magnetic field; non-ferrous cookware including glass, ceramic, aluminum and copper will not respond to a magnetic field and consequently will not generate heat.

Induction coils underneath the cooktop generate a magnetic field that excites molecules in the pan, creating heat and cooking the food. Photo courtesy of Thermador

 

Induction cooking may also have the edge over gas and electric in terms of safety as the cooktop itself can not generate any heat, and can only get as hot as the cookware. The coil produces energy only when a pan is detected on the burner, which shuts off automatically when the pan is removed or if its contents boil over. Also, the lack of an open flame and hot cooktop reduce the risk of burns. Its flat, smooth surface makes it easier to clean than other types of cooktops. Drawbacks to induction cooking boil down to cost − that of the cooktop itself, and a ferromagnetic set of cookware.

Regardless of heat source, glass stove tops incorporate technology to improve cooking performance over traditional electric coil options. Some models feature infrared sensor technology that continuously measures the heat from cookware. The electronic circuit compares the actual temperature of the pot with the programmed temperature and regulates the element accordingly. The sensor automatically cycles the burner on and off in milliseconds to maintain the precise temperature needed while preventing boil over. Even when put to the ultimate chocolate test, the infrared sensor technology can ensure that chocolate is melted and kept without burning for hours. This new technology not only ensures a good cooking result, but it is more energy efficient as it uses only the energy needed. Many models also come equipped with a version of electronic touch-sensitive controls that are activated by moving a finger over certain areas to indicate the preferred burner and heat level. Two light touches of the finger will turn on each electric element, and one touch turns them off. All elements can be extinguished simultaneously with a single touch, and a longer touch locks the entire unit for easy cleaning and child-proofing, making the unit safer and more convenient.

One major advantage of glass-ceramic cooktops over other styles is their smooth surfaces uninterrupted by drip pans, knobs or dials, which makes them extremely easy to clean.

Oven Technology

High end models combine speedcooking ovens with convection ovens in handsome wall-mounted configuration.

Advances in oven technology have resulted in improvements in the way food is cooked, and the amount of time and energy expended. Consumers appreciate the modular appeal of various types of ovens and warming drawers that can be customized to fit their schedules and cooking styles.

Conventional Ovens. Traditionally, most U.S. homes have modern conventional ovens. Conventional ovens cook with heat, using either gas or electricity. Because air is not forced throughout the oven on a constant basis with the aid of a fan, heat circulation can become blocked by pots and pans, which leads to unevenly cooked food, particularly if both racks are in use. Food on the top rack will cook faster as heat rises and gets trapped at the top of the oven.

Convection Cooking. Convection ovens use a fan typically at the back of the oven to circulate air around the food being cooked. Because the heated air is constantly moved around the food, a convection oven cooks food more thoroughly and about 20 percent faster than a conventional oven at about 20 percent lower temperatures. With consistent air circulation, food will cook at the same rate regardless of its placement in the oven. Typically the province of the restaurant industry, convection ovens − and those that switch to a convection mode on request − are becoming more popular in residential kitchens. Sophisticated convection ovens for home cooks use a baffle system to more precisely direct the heat toward the food, resulting in even faster more even cooking than convection ovens that use fans.

Speedcooking Ovens. Speedcooking ovens are aimed at busy professionals, particularly dual-income families working long hours that have no time for home cooking. Because they can deliver savory, nutritious meals at a fraction of the time of conventional ovens, speedcooking ovens not only offer energy efficiency benefits, but they add to the quality of life and support the health and well being of time-pressed consumers.

The microwave was long considered to be the leader in terms of cooking and heating convenience, even though the food quality was missing. Speedcooking technology combines microwave technology with other heating systems − and manufacturers say the latest models cook food up to 50 percent faster than conventional ovens while retaining savory results. Speedcooking ovens deliver a roast chicken in 20 minutes, a rack of lamb in seven, and cookies in less than two minutes.

While combination microwave convection ovens have been around for decades, the difference is that these next generation ovens use conventional heating, convection blowers, halogen or quartz bulbs as the primary heat source. Microwaves just speed up the process. One scenario operates as follows: high-speed blowers shoot air into the oven from holes at the top and bottom and recirculate it through holes in the back wall. Microwaves are introduced from behind the top of the ceramic oven ceiling where a dual-purpose, metal baffle mixes both the microwaves and the air streams to hit the food at specified angles. Improvements in convection technology involving two way vertical convection that channels air directly onto the food enables the newest models to lower cooking times by 75 percent vs comparable older versions which averaged cooking times 50 percent faster than conventional ovens.

Higher end models have automatic conversion functions − all that is needed is to put the food in the oven, set the time for conventional cooking, and it is automatically adjusted to the proper speedcooking equivalent. Controls have pre-programmed recipes geared to the correct time and temperature for many standard dishes. The technology comes packaged in a variety of forms, from countertop, to over-the-range to a double built-in wall oven over a standard thermal or convection oven. The largest models offer more than 4 cubic feet of capacity and accommodate standard cookware, though many models are significantly smaller and require special microwave-safe cooking utensils and turntables.

High Design and High Performance Today's kitchen appliances have a luxury appeal. But the truth is they are also high performance machines that making cooking easier and faster and increase the safety, shelf life and quality of food. The result is a more healthful life style for consumers and energy efficiency that has a positive impact on the environment and the move toward carbon-neutral living.

Thermador has been at the forefront of cooking technology for more than seven decades, fusing state-of-the-art performance with classic design to satisfy the most demanding culinary enthusiasts. From introducing the first built-in wall oven to revolutionizing gas cooktops with the patented Star® Burner, Thermador's innovations have revolutionized the American home.  www.thermador.com