Go walkabout

Most organisations could use a lot less energy. In fact the Carbon Trust’s experience shows that even low and no-cost actions can usually reduce energy costs by at least 10 per cent and produce quick returns. 63 per cent of organisations say that they are now taking action to reduce energy use in their operations. This makes a lot of sense because for many businesses a 20 per cent cut in energy costs represents the same bottom line benefit as a five per cent increase in sales.

There are a lot of options when it comes to energy use, which range from looking at staff behaviour to installing renewable technologies. Some technologies that have a significant potential for savings, such as compressed air or refrigeration, are not relevant to every organisation. This guide will focus on areas that are applicable to almost every single business in the UK: heating and lighting.

Energy Walk Round
To identify where energy savings can be achieved, it is essential to start by looking at how energy is currently being used. Conducting a walk round with a checklist will identify what is actually happening on the ground, wasteful energy use, and opportunities for savings.

It will also demonstrate a commitment to improving energy performance. The areas to look at on a walk round are heating, lighting, office equipment and, if applicable, factory and warehouse equipment. As the pattern of energy use will differ throughout the day, it is useful to conduct a series of walk rounds and to vary the times that they are carried out, for example: when the cleaners are on duty, at lunchtime, at night or over weekends, and at a time when you would expect to be using little or no energy.

Varying the times of walk rounds will provide a better picture of when and where energy might be being wasted. It is helpful to plan future walk rounds for dates such as when the clocks change and at the beginning and end of the heating season. This will ensure that controls are set correctly for the time of year. Key members of staff can and should get involved with walk rounds, both to help identify problems and opportunities and to ensure they feel part of the process.

Comparing the findings of the walk round with meter data will help to pinpoint areas of high energy use. It is important to prioritise energy saving actions once they have been identified, rather than expecting to do everything at once. Usually, those with the biggest savings potential or least disruption to the business will decide this. In some cases the savings are easy to identify and calculate; this guide should help you

Heating
Heating typically accounts for about half of the energy used in offices and forms a significant proportion of energy use in other areas of a business. It is a key area to target with energy saving measures. Many buildings are overheated which can cause discomfort and wastes money.

Overheating is often the result of heating areas that do not need to be warmed (such as storage areas or corridors) to the same temperature as those that do, such as occupied areas. Overheating can also be the result of poor control of heating systems.

Preventing as much heat loss as possible through improving insulation and draught control can also significantly reduce heating bills. Key areas and issues to look out for when carrying out an energy walk round, are:

When were the heaters or boilers last serviced? Heating costs can increase by 30 per cent or more if a boiler is poorly operated or maintained. Ensure they are serviced at least annually and adjusted for optimum efficiency.

Is there evidence of use of portable heaters? Portable electric heaters are expensive to run. If portable heaters have to be used, install a simple time switch so they turn themselves off after a designated period, for instance 30 minutes.

Are there heaters and air conditioning units operating simultaneously in the same space? Simultaneous heating and cooling of a space is commonplace and wastes a lot of money. Set a ‘dead band’ of 5°C between heating and cooling, to avoid this happening. Heating costs rise by about 8 per cent for every 1°C of overheating

How is the hot water provided? Consider installing local instantaneous water heaters where small quantities of hot water are required a long way from the main heating plant. This may also allow the main boiler to be switched off in the summer. Insulate all hot water tanks, boilers, valves and pipework unless they provide useful heat to occupied spaces.

Do all areas have the same heating requirements? Consider heating the building in zones to allow heating to be adjusted for each area. Areas such as storerooms and corridors, or areas where there is a high level of physical activity, require less heat. Warehouses are sometimes heated in an attempt to reduce humidity and maintain product quality, but warm air can often hold more moisture than cold air and heating may actually increase humidity. Dehumidification can be more efficient for this purpose. Remember the effect of sunlight – are you heating areas that are already warmed by the sun?

Are thermostats correctly set? Thermostats should generally be set at 19-20°C for heating. Install thermostatic radiator valves where possible to provide local control of radiators and make sure they are used correctly.

Are thermostats placed in the correct locations – away from draughts and direct sunlight and at a distance from any heating sources? Zone controls allow heating or cooling of different parts of a building at different times and different temperatures according to occupants’ needs.

Are time controls correctly set? Does heating come on only when needed? Control heating using seven-day timers to allow it to be turned off or down during regular unoccupied periods. Money can be saved by adjusting any preheat period in the morning to match weather conditions. Controls are available that can do this automatically.

How are extract fans, for example in toilets, controlled? Fans left running extract warm air and waste money – consider fitting time switches or occupancy detectors.

Are windows and doors left open during the heating season? Windows are often opened because rooms are too hot. Instead of opening windows, turn down thermostats a little until a comfortable temperature is reached. Use promotional material and staff meetings to raise staff awareness.

Are there cold draughts coming from windows and doors? Draughts are not only a cause of complaint and discomfort, but waste money. Fit draughtstrips and seal up windows and doors that are no longer used.

Lighting
There are many simple and inexpensive ways to reduce the energy consumption and costs associated with lighting without compromising health and safety or comfort levels. It is possible to cut your lighting costs by up to 30 per cent by implementing energy saving measures outlined in this overview. Lighting a typical office overnight wastes enough energy to heat water for 1,000 cups of tea. Key areas and issues you should look out for when carrying out an energy walk round are:

What type of fluorescent tubes are in use? Slimline fluorescent tubes (26mm diameter) use 10 per cent less electricity and are cheaper to buy than the older 38mm tubes. Installing new high frequency fluorescent lighting eliminates flicker and hum, extends lamp life and can often reduce consumption by around 25 per cent.

Are lamps, fittings and rooflights clean? Dirty shades and rooflights greatly reduce lighting levels.

Are standard (tungsten) light bulbs still being used? These bulbs are very expensive to run for long periods and produce more heat than light. Replace standard light bulbs with more efficient compact fluorescent bulbs – they have a longer life, lower maintenance costs and use up to 75 per cent less energy. ‘Task lighting’ is a good way to minimise the amount of electric light being used, by lighting just the working area to a higher level and providing background lighting at a lower level for the rest of the space. The use of ‘task lighting’ can also reduce glare on computer screens making it more comfortable for employees.

Is there an opportunity to use LEDs? LED lighting can provide substantial energy savings. LEDs typically have a long lifetime and will need less frequent replacement than many other lighting types. Lighting in a typical office costs about £3/m2 annually, but in the most efficient office only costs about £1/m2.

How are lights turned on and switched off? Banks of lights are often controlled by a single switch. Consider installing more switches or pullcord switches to improve control of individual fittings. Fluorescent tubes use only a few seconds’ worth of power in start up – therefore, it is always better to switch them off when leaving a room.

Is the exterior lighting always switched off when it is not needed? Exterior lighting should be limited to the hours of darkness. It may not be necessary to have lights on continuously throughout the night. Consider fitting lighting controls to limit hours of use.

Are lights switched off when the premises are not occupied? A lot of energy is wasted when unnecessary lights are left on out of hours. Carry out an out-of-hours check to see if this is a problem. Make staff responsible for switching off the lights.

Further information
For sector specific advice and technology overviews, visit the Carbon Trust website at www.carbontrust.com/resources