ISTL Green - Hints and Tips
Reducing Energy Consumption
When to Turn Off Personal Computers
Though there is a small surge in energy when a computer starts up, this small amount of energy is still less than the energy used when a computer is running for long periods of time. For energy savings and convenience, consider turning off:

  • the monitor if you aren't going to use your PC for more than 20 minutes
  • both the CPU and monitor if you're not going to use your PC for more than 2 hours.

Make sure your monitors, printers, and other accessories are on a power strip/surge protector. When this equipment is not in use for extended periods, turn off the switch on the power strip to prevent them from drawing power even when shut off. If you don't use a power strip, unplug extra equipment when it's not in use.

It's commonly assumed that washing dishes by hand saves hot water. However, washing dishes by hand several time a day can be more expensive than operating an energy-efficient dishwasher. You can consume less energy with an energy-efficient dishwasher when properly used and when only operating it with full loads.

When purchasing a new dishwasher, check the EnergyGuide label to see how much energy it uses. Dishwashers fall into one of two categories: compact capacity and standard capacity. Although compact-capacity dishwashers may appear to be more energy efficient on the EnergyGuide Label, they hold fewer dishes, which may force you to use it more frequently. In this case, your energy costs could be higher than with a standard-capacity dishwasher.

One feature that makes a dishwasher more energy efficient is a booster heater. A booster heater increases the temperature of the water entering the dishwasher to the 55ºC recommended for cleaning. Some dishwashers have built-in boosters, while others require manual selection before the wash cycle begins. Some also only activate the booster during the heavy-duty cycle. Dishwashers with booster heaters typically cost more, but they pay for themselves with energy savings in about 1 year if you also lower the water temperature on your water heater.

Another dishwasher feature that reduces hot water use is the availability of cycle selections. Shorter cycles require less water, thereby reducing energy cost.

Clothes Washers
Unlike dishwashers, clothes washers don't require a minimum temperature for optimum cleaning. Therefore, to reduce energy costs, you can use either cold or warm water for most laundry loads. Cold water is always sufficient for rinsing.

Inefficient clothes washers can cost three times as much to operate than energy-efficient ones. Select a new machine that allows you to adjust the water temperature and levels for different loads. Efficient clothes washers spin-dry your clothes more effectively too, saving energy when drying as well. Also, front-loading machines use less water and, consequently, less energy than top loaders.

Small-capacity clothes washers often have better EnergyGuide label ratings. However, a reduced capacity might increase the number of loads you need to run, which could increase your energy costs.

Lower Water Heating Temperature for Energy Savings
You can reduce your water heating costs by simply lowering the thermostat setting on your water heater. For each 5ºC reduction in water temperature, you can save between 3%–5% in energy costs.

Reducing your water temperature also slows mineral buildup and corrosion in your water heater and pipes. This helps your water heater last longer and operate at its maximum efficiency.

Mark the beginning temperature and the adjusted temperature on the thermostat dial for future reference. After turning it down, check the water temperature with a thermometer at the tap farthest from the water heater. Thermostat dials are often inaccurate. Several adjustments may be necessary before you get the right temperature.

Compact Fluorescent Lamps
Your home is installed with at least the minimum number of compact fluorescent lamps (CFLs) recommended by part L of the building regulations. These lamps combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures.

CFLs can replace incandescents that are roughly 3–4 times their wattage, saving up to 75% of the initial lighting energy. Although CFLs cost 3–10 times more than comparable incandescent bulbs, they last 6–15 times as long (6,000–15,000 hours). Replace lamps as they fail consider using standard or table lamps utilising compact fluorescent technology

When to Turn Off Your Lights
The cost effectiveness of when to turn off lights depends on the type of lights and the price of electricity. The type of light is important for several reasons. All types of lights have a nominal or rated operating life, which is the total number of hours that they will provide a specified level or amount of light. However, the operating life of all types of light bulbs is affected by how many times they are turned on and off. The more often they are switched on and off, the lower their operating life. The exact number of hours that switching lights on and off reduces the total operating life depends on the type of light and how many times it is switched on and off.

Incandescent Lighting
Incandescent lights (or bulbs) should be turned off whenever they are not needed. Nearly all types of incandescent light bulbs are fairly inexpensive to produce and are relatively inefficient. Only about 10%–15% of the electricity that incandescent lights consume results in light—the rest is turned into heat. Turning the light(s) off will keep a room cooler, an extra benefit in the summer. Therefore, the value of the energy saved by not having the lights on will be far greater than the cost of having to replace the bulb.

Fluorescent Lighting
The cost effectiveness of turning fluorescent lights off to conserve energy is a bit more complicated., a general rule-of-thumb for when to turn off a fluorescent light is if you leave a room for more than 15 minutes, it is probably more cost effective to turn the light off. Or in other words, if you leave the room for only up to 15 minutes, it will generally be more cost effective to leave the light(s) on. In areas where electric rates are high and/or during peak demand periods, this period may be as low as 5 minutes.

Energy Savings
To calculate the exact value of energy savings by turning a light off, you need to first determine how much energy the light(s) consume when on. Every bulb has a Watt rating printed on it. For example, if the rating is 40 watts, and the bulb is on for one hour, it will consume 0.04 kWh, or if it is off for one hour, you will be saving 0.04 kWh. (Note that many fluorescent fixtures have two or more bulbs. Also, one switch may control several fixtures—an "array." Add the savings for each fixture to determine the total energy savings.)

Lighting Dimmer Controls
Adding additional dimmer controls provide variable indoor lighting for incandescent and fluorescent lamps. When you dim these lamps, it reduces their wattage and output, which helps save energy.

Off-the-shelf dimmers for incandescent fixtures are inexpensive and provide some energy savings when lights are used at a reduced level. Dimmers also increase the service life of incandescent lamps significantly. However, dimming incandescent lamps reduces their lumen output more than their wattage. This makes incandescent lamps less efficient as they are dimmed.

Dimming fluorescents requires special dimming ballasts and lamp holders, but does not reduce their efficiency. Fluorescent dimmers are dedicated fixtures and bulbs that provide even greater energy savings than a regular fluorescent lamp.

Lighting Motion Sensor Controls
Motion sensors automatically turn outdoor lights on when they are needed (when motion is detected) and turn them off a short while later. They are very useful for outdoor security and utility lighting provided by incandescent lamps.

Because utility lights and some security lights are needed only when it is dark and people are present, the best way to control might be a combination of motion sensor and photosensor.

Incandescent flood lights with a photosensor and motion sensor may actually use less energy than pole-mounted high-intensity discharge (HID) or low-pressure sodium security lights controlled by a photosensor. Even though HID and low-pressure sodium lights are more efficient than incandescents, they are turned on for a much longer period of time than incandescents using these dual controls.

When turned on, HID and low-pressure sodium lamps can also take up to ten minutes to produce light. Therefore, they don't work well with just a motion sensor.

Replacing Lamps in Incandescent Lighting Fixtures
You can reduce lighting costs by replacing lamps in or "relamping" your older incandescent lighting fixtures.

Many older indoor lighting fixtures trap a significant portion of light inside the fixture. Newer incandescent fixtures are designed to push all their light out into the room. Others use smaller tungsten halogen lamps. Advances in indoor fixture design include brighter reflectors and better reflecting geometry.

Lighting Maintenance
Maintenance is vital to lighting efficiency. Light levels decrease over time because of aging lamps and dirt on fixtures, lamps, and room surfaces. Together, these factors can reduce total illumination by 50% or more, while lights continue drawing full power.

The following basic maintenance suggestions can help keep your lights operating at their optimum energy efficiency:

  • Clean fixtures, lamps, and lenses every 6–24 months by wiping off the dust. However, never clean an incandescent bulb while it is turned on. The water's cooling effect will shatter the hot bulb.
  • Replace lenses if they appear yellow.
  • Consider group relamping. Common lamps, especially incandescent and fluorescent lamps, lose 20%–30% of their light output over their service life. Many lighting experts recommend replacing all the lamps in a lighting system at once. This saves labor, keeps illumination high, and avoids stressing any ballasts with dying lamps.
  • Clean or repaint small rooms every year and larger rooms every 2–3 years. Dirt collects on surfaces, which reduces the amount of light they reflect.