Top tips for achieving energy efficiency

It is possible to make big energy savings by optimising the way we use our current infrastructure. In addition there are a number of low cost methods to significantly increase the efficiency of buildings. Here are some tips organised by type:

LIGHTING
Through maximising use of daylight, using the most efficient technologies available and use of ambient/task lighting, energy use for lighting could be reduced by between 75-90% compared with conventional practice (IPCC 2007).

• Consider needs in each area and light accordingly. Play around with options and maximise control over lighting. Consider rewiring switches so you don’t have one controlling multiple areas and workstations. What about desk lamps? What about movement-sensitive lighting?
• Low-energy bulbs (also called Compact Fluorescent) use much less energy than traditional bulbs and last up to 10 times longer. These types of bulb sometimes have a poorer quality of light than their incandescent counterparts if you follow packet instructions. Consider using slightly higher wattage than recommended on the CF packets – e.g. rather than replacing a 75 watt incandescent with a 14 watt CF bulb, use a 20 watt CF bulb instead. You don’t get quite the level of savings – but still a 70% reduction.
• Ensure lights are switched off when not in use with signs and goodbye messages on the computer. Develop conventions for communal areas, such as corridors. The Carbon Trust suggests this can save up to 15% on lighting costs.

Photos courtesy of Nicholas Liby and Liz West

A nice over-view of a lighting audit can be found here. It is American but still relevant and helpful.

HEATING & COOLING
For every increase in temperature of 1◦C you will increase heating costs by 8% (Carbon Trust 2005).

• Don’t heat unused/transit areas and switch off or lower heating/cooling over weekends and holidays.
• Consider behaviour in relation to heating: encourage people to put on a jumper before turning up the heating, consider thermostatic radiator valves, turn down heating rather than opening windows, use blinds to cool buildings in the summer.
• Use energy efficient boilers and maintain boilers, ventilation systems and seals around windows and doors – the Carbon Trust suggest you could be adding as much as 10% to your heating bill if equipment is not regularly checked. Ensure that all hot water pipes are covered in pre-cut insulation tube and replace this where it is damp or cracked.
• Consider installing energy saving window film. Window film will significantly reduce solar heat and glare as well as winter heat loss. It can be applied to any window but will have the most significant effect on single glazed windows. The film has a low emissivity (‘low e’) coating that reduces heat by over 80% helping to lower air conditioning bills in the summer and stops 33% of winter heat loss, which helps you to save energy on winter fuel bills. Low e window film also has a one way mirror reflective surface so it allows clear vision out but gives a silver mirrored appearance when looking in, providing daytime privacy. Film costs about £20 per square meter.
• Check heating or air conditioner filters each month, and clean or replace them as needed. Dirty filters block air flow through your heating and cooling systems, increasing your energy bill and shortening the equipment’s life.
• Install on demand water heating. Why keep a large tank of water hot all the time? Next time you renovate toilet facilities install ‘on demand’ water heaters. If you must keep old water heaters see if you can shut them off at night when not in use. Keeping water hot 24/7 uses a great deal of energy. Check the temperature setting on your boiler. Water should be heated to 60 degrees Celsius but the water coming out of the hot tap should be no warmer than 50 degrees.

Photos courtesy of Andy Butkaj, Jeff Framer and Max Talbot-Minkin

BUILDING FABRIC
Improvements in the thermal envelope can reduce heating requirements by a factor of two to four compared to standard practice (IPCC 2007).

• If you have considerable heating demand, then make sure your roof and walls are well insulated and leakage is minimised.The easiest and most cost-effective way to insulate your school is to add insulation in the roof. If you have less than 6 or 7 inches, you can probably benefit by adding an additional 3 or 4 inches.
• Get good quality advice prior to any large scale retrofitting, as you also need to account for ventilation systems, potential future cooling demand of your building given a changing climate, and moisture control in buildings.

Photos courtesy of Mark Evans and Theilr

ELECTRONIC DEVICES
Appliances on standby can use up to 10% of the power they use when operating normally (Ross and Meier 2000).

• Activate "sleep" features on computers and office equipment that power down when not in use for a while.
• Turn off equipment rather than leaving it on standby during longer periods of non-use to cut energy costs and improve longevity.

Photos courtesy of Ross Neugeboren, Pualv and Clifton Raffel