This blog post is taken from info posted in the public domain. It specifically addresses saving electricity. Jeffries electric has great residential electric repairs and commercial electric repairs. We install 200 amp panels and replace federal breaker panels. We install landscape lights and recessed lights. We fix electrical plugs and electrical switches and 3 way switches. we are your Denton electrician, Coppell electrician, lewisville electrician, highland village electrician, Frisco electrician, Plano electrician, corinth electrician. We fix gfci plugs and repair breakers. We install whole house surge protector. Licensed electrician and insured electrician. Add phone outlets. We repair landscape lights. We fix light switches. Install ground rod. Electric repair work should be performed by a licensed electrician. Be safe and turn off the breaker first.Jeffries Electric is a GSA shedule holder.
Indoor Lighting Design
When designing indoor lighting for energy efficiency, you want to consider some basic design principles and methods.
Energy-efficient lighting design principles include the following:
- Remember that more light is not necessarily better. Human visual performance depends on light quality as well as quantity.
- Match the amount and quality of light to the performed function.
- Install task lights where needed and reduce ambient light elsewhere.
- Use energy-efficient lighting components, controls, and systems.
- Maximize the use of daylighting.
Here are some basic methods for achieving energy-efficient indoor lighting:
- Install fluorescent light fixtures for all ceiling- and wall-mounted fixtures that will be on for more than 2 hours each day. These often include the fixtures in the kitchen and living room, and sometimes those in bathrooms, halls, bedrooms, and other higher-demand locations.
- Install dedicated compact fluorescent fixtures, rather than compact fluorescent lamps (CFLs) in incandescent fixtures, so that fluorescent bulbs continue to be used for the life of the house.
- Use CFLs in portable lighting fixtures that are operated for more than 2 hours a day.
- Use ENERGY STAR® labeled lighting fixtures.
- Use occupancy sensors for automatically turning on and off your lights as needed.
- Consider light wall colors to minimize the need for artificial lighting.
- If recessed lights are used in a ceiling with an unconditioned space above it, use only Underwriters Laboratory (UL) approved fixtures that are airtight, are IC (insulation contact) rated, and meet ASTM E283 requirements.
Lighting Principles and Terms
To choose the best energy-efficient lighting options for your home, you should understand basic lighting principles and terms.
Light Quantity
- Illumination
- The distribution of light on a horizontal surface. The purpose of all lighting is to produce illumination.
- Lumen
- A measurement of light emitted by a lamp. As reference, a 100-watt incandescent lamp emits about 1750 lumens.
- Footcandle
- A measurement of the intensity of illumination. A footcandle is the illumination produced by one lumen distributed over a 1-square-foot area. For most home and office work, 30–50 footcandles of illumination is sufficient. For detailed work, 200 footcandles of illumination or more allows more accuracy and less eyestrain. For simply finding one’s way around at night, 5–20 footcandles may be sufficient.
Energy Consumption
- Efficacy
- The ratio of light produced to energy consumed. It’s measured as the number of lumens produced divided by the rate of electricity consumption (lumens per watt).
Light Quality
- Color temperature
- The color of the light source. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an overcast sky) are considered cool. Color temperature is measured in Kelvin (K) temperature. Confusingly, higher Kelvin temperatures (3600–5500 K) are what we consider cool and lower color temperatures (2700–3000 K) are considered warm. Cool light is preferred for visual tasks because it produces higher contrast than warm light. Warm light is preferred for living spaces because it is more flattering to skin tones and clothing. A color temperature of 2700–3600 K is generally recommended for most indoor general and task lighting applications.
- Color rendition
- How colors appear when illuminated by a light source. Color rendition is generally considered to be a more important lighting quality than color temperature. Most objects are not a single color, but a combination of many colors. Light sources that are deficient in certain colors may change the apparent color of an object. The Color Rendition Index (CRI) is a 1–100 scale that measures a light source’s ability to render colors the same way sunlight does. The top value of the CRI scale (100) is based on illumination by a 100-watt incandescent light bulb. A light source with a CRI of 80 or higher is considered acceptable for most indoor residential applications.
- Glare
- The excessive brightness from a direct light source that makes it difficult to see what one wishes to see. A bright object in front of a dark background usually will cause glare. Bright lights reflecting off a television or computer screen or even a printed page produces glare. Intense light sources—such as bright incandescent lamps—are likely to produce more direct glare than large fluorescent lamps. However, glare is primarily the result of relative placement of light sources and the objects being viewed.
Lighting Uses
- Ambient lighting
- Provides general illumination indoors for daily activities, and outdoors for safety and security.
- Task lighting
- Facilitates particular tasks that require more light than is needed for general illumination, such as under-counter kitchen lights, table lamps, or bathroom mirror lights.
- Accent lighting
- Draws attention to special features or enhances the aesthetic qualities of an indoor or outdoor environment.
Jeffries electric has great residential electric repairs and commercial electric repairs. We install 200 amp panels and replace federal breaker panels. We install landscape lights and recessed lights. We fix electrical plugs and electrical switches and 3 way switches. we are your Denton electrician, Coppell electrician, lewisville electrician, highland village electrician, Frisco electrician, Plano electrician, corinth electrician. We fix gfci plugs and repair breakers. We install whole house surge protector. Licensed electrician and insured electrician. Add phone outlets. We repair landscape lights. We fix light switches. Install ground rod. Electric repair work should be performed by a licensed electrician. Be safe and turn off the breaker first.
