Specifying a new catering facility? Read on for how to achieve maximum water and energy efficiencies.
If you offer any kind of catering you know that success includes the menu you offer, the customer experience, and the feeling customers get from eating at your venue. But every passing year is an opportunity to improve other aspects. Renovating your kitchen could be the occasion to make your establishment more sustainable and make savings on your bills.
Renovating your kitchen is different from the many changes you can introduce gradually, such as adding sustainable local products to your menu or progressively changing your providers to those that have better environmental policies. Those changes are ‘easy’ because they are not definitive – you can change your decision and re-introduce some of your previously popular dishes if the alternatives don’t work out.
Renovating your kitchen, however, should be done in one go (you don’t want to find yourself closing and dismantling your kitchen every six months to change just one thing!) and ideally once and for all. Here, going back on your decision is much more difficult and costly – this is why you need to prepare thoroughly.
Serious change – serious gain
When you plan to renovate your kitchen, it is essential to benefit from the renovation as a great opportunity to limit your consumption of energy and water.
There is a wide variety of appliances on the market and the choice can be daunting. This article presents six that generate the most water and energy savings. Choosing the most efficient models will save your venue considerable money on annual energy and water bills.
Pre-Rinse Spray Valves (PRSVs)
The use of high pressure rinsing nozzles to prewash dishes before putting them in dishwashers is a very common practice. However, pre-rinse spray valves can account for 30% of all water used in the kitchen! When choosing a new PRSV, opt for a model with low-flow nozzles using less than 6 litres/minute. It will be a huge gain in water consumption as regular nozzles use even three times more (15 litres/minute). Also, look for sensor-activated models assuring the water is sprayed only when needed.
Dishwashers are responsible for another 30% of the water use in a typical restaurant’s kitchen. Efficient dishwashers can even halve your current water consumption! For an average restaurant, choosing an efficient dishwasher can result in savings of 150m3 of water per year. It is, however, not only the question of water saving – as water consumption is very much linked to energy and detergent consumption.
A lot of energy is used to heat up water, and reducing the amount by a few litres at every cycle or reducing the temperature at which the water is heated will have a direct effect on your electricity bill. Additionally, with dishwashing chemicals that have a constant dilution rate per litre of water, the less water you use, the less detergents are needed in the machine.
Dishwashers are available in many sizes and types, and are usually classified in three groups:
• Under-counter or over-counter stationary front-loaders
• Stationary and pass-through hood-types
• Rack conveyor machines and large flight type machines.
Unless you have a very large kitchen, hood-type dishwashers are likely to be the most appropriate for you (while tunnel dishwashers are used in larger establishments needing the capacity to wash dishes for over 500 meals per hour). The ideal model should:
• Use less than 3 litres of water per rack in case of stationary (under-counter or hood type) dishwashers and less than 2 litres of water per rack in case of conveyor dishwashers. It is important to check because average commercial dishwashers use considerably more (3.8 litres per rack)
• Limit heat losses thanks to good insulation (at least 20mm)
• Include a drying air heat recovery system
• Have appropriate programmes and options so that you can optimise settings in relation to how dirty the serving ware is
• Enable you to connect it to the kitchen hot water supply, which is likely to heat up the water much more efficiently than the dishwasher itself.
Steamers for cooking
If you use a steamer to cook, you should know that an efficient steamer can use over 10 times less water than the old boiler steam cooker you may have. So-called ‘connectionless’ or ‘boiler-less’ steamers use 8 litres an hour (instead of the 100 litres per hour by recycling steam in heated water reservoirs.
For an average restaurant, the installation of an efficient steamer could save 200m3 of water per year.
Besides savings in water consumption, selecting the most efficient appliances can bring even more considerable savings in terms of energy. Here are three appliances that will further help optimise the energy consumption in your kitchens.
Typical hobs will serve you 20 years so it is crucial to choose the right one. Gas and induction hobs are the most efficient. Which one to choose? It depends on the source of the electricity – if it is renewable, then opt for induction cookers, and if not (meaning sourced from fossil fuels), choose gas hobs.
When looking at fridges, freezers or cold room installations, you should check two parameters: the specific energy consumption (measured in kWh of electricity per litre of volume per year) and the refrigerant leakage rate. For large solid door upright cabinets, you should look for fridges with a specific energy consumption of less than 1.14 kWh/l/year and freezers consuming less than 3.6 kWh/l/year.
Ideally, if you redesign the fridges in your kitchen, you should also design them so that they are well insulated and you don’t have to open and close large doors all the time. Finally, your equipment should be well maintained to minimise leaks, and also use refrigerants with low global warming potential, such as hydrocarbons, ammonia or CO2 to limit the environmental impact of any refrigerant leakage.
Ventilation and heating
Kitchens usually generate a lot of heat, and there are ways in which you could save money by managing your ventilation more efficiently. Check the speed of your ventilation or extractor fan. Huge energy gains could be made if it runs too fast by slowing it down – you could consume up to 87% less if the fan turns at half the speed!
You can also think of installing processor-controlled fans, which could cut your energy consumption by more than half. Such an investment can have a return of about a year (depending of course on the size of the kitchen and other parameters). Ask your HVAC expert when you are considering the maintenance or replacement of your fan.
Consider reusing the waste heat from your kitchen too. By using a heat exchanger you can direct the heat generated in the kitchen to other parts of a building that need heating, saving energy consumption.
Ask the staff
For each of the devices described in this article, it is crucial to choose the most appropriate size and make sure that your team uses it in the correct way and to its full capacity (your efforts to consume less water and energy will go down the drain if, for example, your dishwasher operates half-empty). For this reason, check what the needs of your kitchen staff are before making a considerable investment. It is a future-oriented step, both in terms of protecting the environment and cutting costs – and we all know that the prices of both water and energy are going up!