Saving energy not only reduces the climate impact of equipment but saves money too. Regular maintenance and leakage checks are key to keeping your equipment running efficiently, however there are several other ways to reduce your energy bills.
Supermarkets
Cabinet design
There are several ways to reduce the cooling load in supermarkets through improved cabinet design, the single most important being the use of glass doors or lids. Approximately 75 per cent of the cooling load of a refrigeration cabinet is due to air infiltration.
Glass doors or lids can reduce the refrigeration capacity of a supermarket by up to 40 per cent.. Kauffeld, M., J. Harnisch and J.-M. Rhiemeier (2008). Environmental impact of various alternative supermarket refrigeration systems. 8th IIR Gustav Lorentzen Conference, IIR
Correct cabinet loading
Proper cabinet loading and location and can affect energy efficiency. Overfilled open refrigerated cabinets consume up to 6 per cent more energy, while producttemperature can increase by up to 6°C.
Light Emitting Diodes (LEDs)
LEDs consume approximately half the energy used by fluorescent tube lighting and they also reduce the heat load in the cabinet. Furthermore, LEDs consume less energy the cooler they are kept, while the opposite is true for fluorescent tubes. Use of LEDs cantherefore reduce energy use by 60-70 per cent compared to fluorescent lamps.
Heat Recovery
Supermarkets require heat, either to heat space, for processes or for hot water. Despite this, the heat removed by the refrigeration system is oftenwasted. Some or all of this heat can be recovered and used to provide useful heating, reducing gas or oil heating bills.
Air conditioners
Reduce load
Increasing insulation in your home or office, keeping window shades and shutters closed during the day and limiting air leakage from the cooled room will reduce the workload of your air conditioner. Turn off your air conditioner when not in use.
Increase setting temp
According to the US Department of Energy, the optimal temperature for air conditioning during summer months is 26°C (78°F).
Adjusting your air-conditioner up a few degrees will help cut energy usage. You can use a fan to create a breeze to help you adjust to the warmer temperature.
Clothing/dress code
Temperatures in modern offices are often set very low to accommodate business dress code. A simple solution is to loosen the dress code in offices and increase the air conditioning setting temperature. Japan’s Cool Biz initiative, which began in 2005, encourages workers to dress casually (without ties and jackets) and urges offices and homes to set their air conditioners at 28°C throughout the summer months. Japan also has a ‘Cool share’ campaign to encourage people to gather in air-conditioned common spaces, like cafes and community centres and even living rooms, to save on individual air conditioning use.
Avoiding Active Cooling
With global temperatures and incomes rising, our demand for cooling is increasing. Having an air conditioner in every home on the planet, even if they were all highly efficient, HFC-free systems, would still place a considerable burden on the climate. We need to rethink cooling. The most sustainable options are those that avoid mechanical vapour compression cooling altogether, and there are many ways to do this.
Passive Cooling
Passive, or non-mechanical, cooling should be incorporated into building design. Building design can eliminate the need for air conditioners through orientation, ventilation, windows, shading, insulation and thermal mass. Different approaches are required depending on the climate.
Cool Roofs
Increasing the solar reflectivity of roofs maximises the amount of sun reflected and minimises the amount of sun entering the building as heat. Painting the roof white is the simplest method of ‘cooling’ a roof, however a range of materials with varying reflectivity exist. Cool roofs are a sustainable passive cooling solution which reduce reliance on mechanical cooling options. Using reflective roof surfaces across a whole community can also help reduce local ambient temperatures.
In 2019, the Kigali Cooling Efficiency Programme (KCEP) in collaboration with the Global Cool Cities Alliance (GCCA), Sustainable Energy for All and Nesta’s Challenge Prize Centre announced the Million Cool Roofs Challenge with the aim of scaling up the deployment of solar-reflective “cool” roofs in developing countries suffering from heat stress. The global competition will provide US$2 million in grants to applicants with the most promising ideas and demonstrated success bringing cool roof innovations to scale.
Insulation
Insulation can help prevent the need for cooling by insulating against heat gains within a building. However,insulation is often blown with climate damaging HFCs or ozone depleting substances, and is primarily made with polyurethane, a plastic product which is rarely, if ever, recycled properly. The foam blowing process also often requires toxic flame retardants. These products consequently have a significant environmentalfootprint. There are plastic-free, HFC-free alternatives for insulation, like Rock Wool. However, if foam insulation is used it should be blown withnatural refrigerants, not HFCs. Natural blowing agents such as pentane or CO2 can be used in all types of foam production. Several large manufacturers have been successfully using the technology for many years to produce high-quality products.
City planning
Air conditioning pumps hot air from cooled rooms outside, heating up the surrounding air. In cities with many AC units running simultaneously this can contribute to the heat island effect. Exacerbated by concrete and cement and a lack of trees and plants, cities are often a few degrees warmer than surrounding rural areas. City planners should take cooling needs into account to create a more comfortable environment and ease the burden on the electricity grid during warmer periods. Strategies include more open green spaces like parks, community cooling centres, district cooling and passive cooling in building design.
