Making the kitchen greener

20 October 2010
Making the kitchen greener

Restaurants use about 2.5 times more energy per square foot than other commercial buildings. Energy costs, meanwhile, have been increasing at a rate of 6% to 8% per year. Investing in energy efficiency, therefore, is the best way to protect your business against rising energy prices.

In general, for a small or medium-sized business, energy costs are going to be anywhere between 7p and 21p per kWh (kilowatt hours) for electricity and between 2p and 6p for gas, depending on location within the UK and the volumes taken.

Most commercial kitchen appliances are energy intensive. For instance, an electric deep-fat fryer that uses more than 11,000 kWh of energy per year could cost you more than £2,300 in electricity. When it comes to energy efficiency even the smallest changes or improvements can make a big impact on an operator's bottom line.

So, what does this all mean for the operator? If we take a look at a typical commercial kitchen, area by area, it is possible to see where changes in layout, equipment and working practices can make a difference, not only to energy consumption, but also to cost.


Start with the basics and consider lighting here. PIR low-energy lighting is best to reduce any risk of lighting being left on when the areas are not in use. Handwash facilities are best specified with sensor taps, such as Mechline Tempomatic, or knee-operated to prevent the brigade as well as delivery drivers leaving taps running. A couple of leaky taps losing only 50ml per minute equates to more than 500 litres per week - if that is on the hot tap you are heating water to send it right down the drain. Get this right and you can achieve water savings of up to 80% (3p per operation, based on hot-cold mixing savings).

Many restaurants don't consider walk-in refrigeration as they cite the initial capital outlay as being prohibitive. But walk-ins offer greater storage capacity and, therefore, reduce the frequency of deliveries, so saving on carbon emissions from transport as well as providing better stock rotation. A 2m x 2m freezer room provides actual storage of 200cu ft, which is equivalent to 10 x 15cu ft chest freezers. This could give you a potential energy saving of £1.95 per day - or more than £700 per year - based on 18.5kW per day for a freezer room, compared to 38kW per day for 10 chest freezers.

Ventilation to stores areas must be considered to remove any heat build-up from refrigerated appliances. Restaurateurs will make more service calls about refrigerated appliances and spend more on energy on equipment having to work much harder in an unventilated area. It's also worth considering having external sited or low-level integral condensers.


The workstations of the modern restaurant kitchen can be numerous zoned areas, especially in larger kitchens, performing differing functions and limiting the risk of cross-contamination. Often, in smaller establishments, they can be in a single area.


The refrigerated counter is the workhorse of the chef's workstation and recent advances in technology have seen many energy savings as a result. One key area is drawer units in counter refrigerators, which can reduce the work rate of compressors and glass doors in upright cabinets, as doors are generally opened less frequently.

Among the recent advances are Adande's individually insulated refrigerated drawer units which provide significant energy savings - cold air does not fall out when the drawer is opened but stays with the food in the insulated drawers. Comparative energy saving tests using energy meters have shown more than 50% metered energy savings compared to an upright work-out freezer. The chef can operate the drawer units to run at chill or frozen temperatures and the temperature of each drawer can be set independently and precisely from -22°C up to 15°C, adapting to the changing needs of catering operations. There is even a facility to utilise a drawer as a blast chiller, saving footprint space within the kitchen.

Additionally, because the cold air stays with the food in the insulated drawer, on every opening the food temperature stability is maintained. This means better food quality and longer storage life, which inevitably reduces food wastage.

All refrigeration should be checked against the Energy Technology List (ETL) in any event. ETL refrigeration products are more than 30% more energy efficient than standard industry models. Manufacturers like Gram have more models listed with ETL than many other manufacturers, offering a wide range of energy-efficient cabinets to suit most types of operation. Gram models also come with a longer warranty than other machines, another factor to bear in mind when choosing refrigeration. Beware the use of domestic refrigeration in a commercial kitchen as it is certainly a false economy, running less efficiently and failing prematurely.

Also, think about where you position your fridge. Avoid placing refrigeration units in direct sunlight, even though most chefs prefer to have their work stations here to maximise natural light.


Preparation sinks should allow for pressure-reducing valves, or taps with inbuilt flow limiting devices or aerators to reduce the volume of water used. Savvy kitchen designers also recommend installing only one cold potable connected water tap, or spray wash device, on food preparation sinks to reduce water consumption further.

Low-flow pre-rinse spray valves also offer tremendous savings in water and any energy used to heat it. While older, less energy-efficient models run at about 22 litres per minute, the newer low-flow models run at less than six litres a minute. Some manufacturers, for example Mechline, now also supply a unit with a unique "gas-strut" which automatically cuts off, further reducing any waste water.


The workhorse of the typical small to medium-sized restaurant kitchen remains the six burner range. Some manufacturers now offer pan sensors which provide energy efficiencies, although energy is still lost around the edge of the pan. These burners only work when the range is being used - when the pan is removed from the cooking surface the flame is extinguished, leaving just the pilot light on so no energy is wasted.

These days, the installation of induction hobs provides some excellent energy saving benefits. Induction cooking works by using special cookware with a ferromagnetic base which is heated by the induction coil in the appliance top. The result is that the heat is generated in the cookware itself, as opposed to being generated on the appliance top, and then passed through the cookware to the food. This is more efficient as the heat is in direct contact with the food and is more easily controllable.

Induction hobs - such as those made by Electrolux, Valera and Induced Energy - offer this benefit, as well as lower running costs, and because they operate more efficiently and more of the heat is taken up into the pan than escaping around it, the kitchen is a cooler place to work in than it would be if a solid top was on all day and there is less need for ventilation.

Another major energy saving benefit is that the appliance senses the voltage drop instantly the induction cookware is removed and automatically shuts off the power supply to the relevant induction coil, meaning it can't accidentally be left on by the chef. This also stops the temptation to use the burners to heat up the kitchen when the chef arrives first thing in the morning.

The low heat gain created by induction appliances also reduces how much ventilation is needed to maintain a comfortable working temperature, which has positive implications for energy efficiency. Less wasted heat results in cooler kitchens, a boon for any chef.

What's more, induction hobs are 50% more efficient than halogen hobs and at least 86% more efficient than gas hobs (source: CSFG).

Although gas prices per kWh are currently significantly lower than electricity, the UK is expected to be importing at least 50% of its total gas needs by 2010 (source: UK Parliamentary Office of Science & Technology) and 80% by 2020 with the potential for more price volatility. However, 38% of electricity is currently produced from gas-fired power stations in the UK.


It's worth looking for salamander grills fitted with individual burner controls to each part as a minimum, and use salamander finishing units with pan sensors, such as the Hatco Quick-therm, which can provide an energy saving of up to 70% against other models and with it a saving of up to £4 per hour.


If a chef wants a chargrill, the trend these days is to avoid lava rock units, as the rock bed can become impregnated with food leading to excessive smoke and adding to the ventilation load. Uneven lava rock distribution also leads to uneven cooking. Some models, for example by Falcon, have a double-sided brander bar design and no lava rock which cuts down on flaring and smoke in kitchen. These chargrills are more energy-efficient too, using nearly a third less energy than traditional models.

Chargrills have significant energy wastage and chrome plated griddles, such as Miraclean units, can cut running costs by 32% thanks to a patented chrome-plated surface which locks in the heat, only releasing on contact. This prevents carbon build up, gives a clean surface to cook on, avoiding cross-flavouring, where food cooks faster and with less shrinkage in size and weight.


It's worth choosing a fryer fitted with an automatic standby mode to sense inactivity and reduce the oil temperature, allowing for a quick recovery - the Falcon Infinity has a 69% reduction in energy costs against some competitors. Filtering generally doubles the life of oil across every mode from serving à la carte to bulk frying, deep or shallow.

Lincat, for instance, has shown its Opus fryers with built-in filtration can provide savings on oil disposal and procurement that pay for a filtration system in less than seven months as well as pay for the fryer itself within 18 months.


Many restaurant kitchens used to have an almost snobbish approach to microwave accelerated cooking but the recent innovations in technology, with systems such as the Merrychef Eikon series, combines three heat technologies in a compact unit to deliver quality hot food at speeds up to 15 times faster than a conventional oven.

A unique combination of convection heat, impingement pressure and electromagnetic energy allows typical cook times from 15-90 seconds. A built-in catalytic converter eliminates the need for a ventilation hood so the oven can operate in virtually any environment, which combined with faster cooking, results in obvious energy savings.


The inclusion of a combination steam-convection oven should be considered as a current model can reduce energy costs by about 50% when compared to other equivalent cooking appliances such as convection ovens. What's more, when compared to a unit heated indirectly with a heat exchanger, a direct-heated gas combi-oven will reduce gas use by 40%.

Some combis, such as Rational, no longer require separate calcium treatment units and have better insulation than other combination ovens with reduced water consumption and electricity savings of up to 12kWh.

A triple-glazed viewing door will save up to 40% of energy compared to a single-glazed door and an automatic fan switch-off, with a brake initiated when the door is opened, will keep hot air inside the oven and minimise heat loss, also helping to maintain a cooler kitchen. Some makes of combi even use their exhaust heat to preheat incoming fresh water for steam generation, saving 30% of the energy input.


Ensuring meals arrive at the table in perfect condition usually requires the ability to hold items and plate up. Rather than having open convection hot cupboards that radiate heat and waste excess energy, a better solution is to look at drawer warmers, such as those manufactured by Hatco, Alto Shaam and Victor, which have a separate compartment, thermostat and humidity control to ensure food is held at the right temperature and doesn't deteriorate. Each drawer is in its own separate compartment so when one drawer is open, the temperature in the other drawers is not affected, and elements are mounted in the cabinet interior rather than the wall, giving faster preheat and recovery.

Heat lamps to the work-surface and over-shelves should be individually controlled so the chef can easily limit the number of lights turned on.


Provide good "dumps" stations with scrapping bins and magnetic cutlery chutes - which help stop breakdowns from cutlery being dropped into the machine. Pre rinse sprays keep the main wash water cleaner for longer which means water will not need to be changed so often. Fill baskets to capacity and stack carefully to prevent "shadowing" resulting in poor washing and dirty dishes.

Then, think carefully about the right dishwasher to maximise energy efficiencies. Certain machines use consistently less water than others. The less water used, the less energy is required to heat the water, and chemical usage is reduced, too. A recent arrival here is the Hobart AUP/AUPR passthrough dishwasher range, which has an ultra low rinse feature which uses just 2.3 litres per cycle. These models have a wash tank capacity of just 10.8 litres, saving on both water and energy, and are capable of removing up to 40% more debris from the wash water, saving about 40% on detergent consumption.

Other manufacturers, such as Meiko with it's B- and K-Tronic machines, have focused on optimised energy management systems to increase the efficiency of exhaust air heat recovery by as much as a fifth, and by optimally pre-heating the rinsing water to reduce energy consumption in the flow heater by a similar amount.

The 500 series pass-through Winterhalter EnergyPlus dishwashers potentially have a saving of 6kW of power and provide better working environment and room air quality without the need for extraction. The units are double-skin insulated which helps retain energy and reduce heat build-up in the wash area, as well as cutting noise.


As landfill costs continue to escalate, the need is apparent for caterers to limit any costly waste collections. With many local authorities and water companies discounting the use of waste disposal units as it "passes the problem down the line", forward-thinking operators are looking at high-speed, high-volume food waste decomposition systems, such as the Mechline GohBio, which introduce natural enzymes into a decomposition machine where organic waste is reduced to grey water that is safe for drains.

For maintaining drains and preventing blockages, there are also some simple and effective solutions available which have a battery-run or mains-powered dosing module filled with specially formulated bio-enzymatic fluid. This highly concentrated liquid breaks down fats, oils and grease - and even starch which builds up in commercial kitchen drains - and is safe to use, easy to handle and store. These systems, such as Mechline's GreasePak, are a cost-effective solution to meet legislative demands and, unlike standard grease interceptors which must be emptied by licensed waste contractors, do not require a collection-disposal contract.


Space Catering Equipment offers a "Green Footprint" scheme to highlight to clients where energy savings can be made and has been working with Blue Sky Energy Solutions to perform project payback and sensitivity analysis of appropriate energy savings.

Space Catering Equipment
01452 383000


Adande Refrigeration
01502 537135

Alto Shaam/Equipline
01895 272236" target="_blank" rel="noreferrer">](

Electrolux Professional
0800 988 2809

Falcon Foodservice Equipment
01786 455227

01322 616900

01509 260140

0844 888 7777

Induced Energy
01280 705900

01522 875500

01908 261511

01753 215120

0845 370 4888

0161-874 5400

0800 388 9294

0845 270 4321

Victor Manufacturing
01274 722125

01908 359000

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