All posts by Editor

How to waste energy No. 3: lighting

1. If your light fittings are the type with translucent diffusers, fill them with dead flies.

2. Avoid replacing tungsten-filament light bulbs with compact fluorescent equivalents. Although it is now illegal to sell most general lighting service (GLS) filament lamps, one can still buy “rough service” equivalents which have the great advantage of being even less energy-efficient.

3. Keep your external lighting on 24 hours a day. This encourages a culture of not caring about leaving things running when idle, and will help waste many times more energy than is used in the lights alone.

4. Also keep your internal lights on continuously, not least because doing so will increase the demand for air conditioning.

5. Provide excessive light levels in working areas and try to ensure that corridors and stairwells are even brighter (this removes one of the vital cues that prompt people to turn lights off when they leave empty rooms).

6. Be careless when specifying automatic lighting controls. Choose the wrong sensor technology, so as to maximise nuisance switching. This has a dual benefit – it encourages people to override the control, and it also antagonises them so they won’t cooperate with other energy-saving initiatives.

7. In shared workplaces, paint over any labels identifying which switch controls which zone.

8. Choose automatic lighting controls with remote control handsets that cannot be understood without training. Then lose the instructions and the remotes.

Link: Energy management training

How to waste energy No. 2: automatic control of buildings

1. Set your frost-protection thermostat at too high a temperature.

2. Override your time control to run the plant continuously.

3. Set heating controls for maximum air temperature. The aim should be to make it so hot that occupants are forced to keep the doors and windows open, increasing the heat loss.

4. Alternatively, place a baked-potato oven under the space temperature sensor. This will hold the heating off and encourage people to bring in electric heaters.

5. If you have adaptive optimum-start control, set the timings as if it were a conventional time-switch (i.e. with start of occupancy at the same time you would previously have asked the plant to start up).

6. Also if you have adaptive optimum-start control, set a target temperature above the daytime control setpoint. The control will add more and more preheat every day because it never achieves the target temperature.

7. If you have air conditioning, set it to cool to a lower temperature than your heating, so that the two systems run simultaneously providing perfect comfort at infinite cost.

8. If you have humidity control, set it for the narrowest range conceivable. This will ensure you are nearly always either humidifying or dehumidifying.

9. Remove or jam the linkages on valve and damper actuators.

10. Do not commission your building energy management system; do not document the control philosophy or agreed settings; and as a backstop, lose the operating manuals.

Link: Energy management training

How to waste energy No. 1: motor-driven equipment

1. When a motor fails, have it rewound, as this will reduce its efficiency.

2. If you need to replace a motor, use the cheapest and least efficient unit available (preferably oversized). Efficiency standards of new motors are being continuously improved, so you may need to shop on eBay.

3. Shift motors slightly on their mounting plates so that any drives and couplings are misaligned.

4. Ensure that drive-belts are slack. On multi-belt drives it can help to remove some belts. If possible, use the wrong kind of belt for the pulleys fitted.

5. Change pulley ratios to drive fans and pumps at higher speed: on centrifugal fans and pumps, a 20% speed increase adds over 70% to the load.

6. Neglect lubrication of bearings and gearboxes.

7. Allow equipment to run continuously, whether it is needed or not. This has the added advantage of accelerating wear and tear, and reducing your power factor.

8. When the driven equipment is decommissioned, at least leave its motor behind, energised and running.

9. In dirty environments, do not clean any debris off motor cooling air inlets. The extra resistance to air flow will increase mechanical losses in the motor and, as a bonus, accelerate its failure by causing it to overheat.

10. In situations where the mechanical output of a fixed-speed motor is controlled and regulated, run the motor below its rated voltage in order to increase the motor current and associated copper losses.

Link: Energy management training

Duty-standby rotation

One of my clients, who operates computer data centres, asked his monitoring and targeting software supplier to conduct some pilot analyses using daily data. Cusum analysis of one particular circuit, which was feeding computer-room air cooling (CRAC) units, threw up an interesting observation: energy performance had been toggling between good and bad on the first of every month. This fact had been masked by the weather and variations in the quantity of energy consumed in the equipment racks, but once revealed, it was traced to the fact that they were alternating two banks of CRACs on a monthly cycle. In situations like this, it pays to change the regime so that preference is given to the more energy-efficient plant. This has the secondary advantage that the standby set will have more maintenance life left in it when the lead set fails. Cusum analysis is very good at providing insights like this, which is why I give it prominence in my training courses on monitoring and targeting.

The other place one finds opportunities for instant savings is multi-boiler heating systems, where, too often, the firing sequence is deliberately rotated to give each boiler the lead and even out the wear. Apart from making no sense in terms of risk management (when one fails, all the survivors will be equally clapped-out) it also misses the opportunity to favour the unit with the highest combustion efficiency, and thereby consume less fuel for a given output of useful heat. Anyone unfamiliar with combustion efficiency and the opportunities that it offers can read up in the A to Z guide at www.vesma.com.

Combustion tuning is a good (and frequently-overlooked) opportunity for nearly all fuel users.

Link: Energy management training

Case history of the month

“How green can you be?” is the message from major energy users Gulley Bull Ltd, who undertook a multi-faceted approach to saving fuel in their head office. They combined magnetic fuel conditioning, which offered a 20% saving, with two kinds of boiler water treatment. One, a simple cartridge containing special stones developed by a NASA scientist, changes a property of water to improve heat transfer by 25%. The other is a patented secret additive which prevents large steam bubbles forming in the boiler and also improves efficiency by 25%. Their building had solid walls, and was hard to insulate, but their energy manager’s researches uncovered a paint additive containing ceramic microspheres which, because they contain a vacuum, act as perfect insulators and promised a 30% saving on their heating costs just from redecorating the offices. Finally, they replaced their heating timeswitch with a control which claims to cuts fuel use by 16% by intermittently turning off the heating, saving fuel without sacrificing comfort: “an ingenious idea which took our total fuel savings to 116%” according to Gulley Bull spokeswoman April Fulstryk.

Super-thin insulation

Super-thin thermal insulation is in my sights at the moment. There are two categories: (a) multi-layer foil and fibre; and (b) paints or paint additives. The insulating effect of multi-layer systems is basically equal to the same thickness of whatever insulating fibre they use, but there is some additional advantage where they are installed with an air gap either side, since they create an extra cavity which has a certain thermal resistance. Their reflective foil will impart additional thermal resistance by preventing radiation from the hot to the cold face of the cavity. But note, however, that after filling with ordinary fibre, the hot and cold surfaces of the cavity can no longer see each other, and heat transfer is solely by conduction. So BOTH techniques eliminate radiative transfer across the cavity and the foil therefore imparts no advantage.

Insulating paints meanwhile, even if composed of material with high thermal resistivity, will have totally negligible effect because the insulating layer is microscopically thin (under 0.3mm by my calculations, based on coverage data in the advertisements). Claims that their ingredients reflect heat are unsound because those so-say reflective materials are buried in the paint layer; to reflect heat the SURFACE of the paint would need to act like a mirror to infra-red radiation.

Link: Energy management training