Efficient home lighting ideas reduce energy costs without sacrificing the beauty and ambience of fine residential lighting design. Consider the fact that lighting constitutes 5-10% of the electrical load on an air conditioned home and up to 25% of the load on a home that uses little or no air conditioning. Most every home on the planet that is powered with electricity uses it for some form of lighting.
Given this widespread application, small improvements add up quickly because of the amount of time the lights remain on as compared with other appliances. Consider the electricity used by your kitchen lights vs. that used by kitchen counter appliances. The toaster, the coffee pot and the blender all draw more power that a few light bulbs. However, at the end of the month it's the lights that use more kilowatt-hours due to run time.
There are three primary lamp technologies which can be drawn upon for home lighting ideas; incandescent, fluorescent and light emitting diode (LED). Incandescent can be further subdivided into standard filament and tungsten halogen. Fluorescent includes the standard tube (T-12), the high efficiency tube (T-8) and compact fluorescents which screw into standard light bulb sockets. LED lamps contain arrays of very long-life diodes that run cool while sipping very small amounts of power.
Conventional incandescent bulbs have been around for well over a century. They are inexpensive and at the same time, inefficient. Fluorescent tubes with magnetic ballasts are three to five times more efficient. T-8 tubes with electronic ballasts increase this efficiency even further. LED's use the least amount of power but have a narrower beam so overall luminous efficiency is on par with T-8 fluorescents.
Which type of bulb will best serve your home lighting ideas? Let's start by looking at the efficacy and the efficiency of the different bulb technologies.
Luminous efficacy is a term used to describe lighting efficiency as the light intensity, in lumens, divided by the power required in watts. Overall efficiency describes the percent of total energy converted to light while the remainder is lost to heat. The following table presents these values for the various sources of illumination.
|Incandescent||100 Watt Tungsten (120v)||12.6||2.6%|
|Incandescent||Tungsten Quartz Halogen (12-24v)||24||3.5%|
|Fluorescent||T-12 with Magnetic Ballast||60||9.0%|
|Fluorescent||T-8 with Electronic Ballast||80-100||12.0-15.0%|
|Fluorescent||32 Watt Compact Fluorescent (CFL)||75||11.5%|
|LED||4.1 Watt Screw Base||58-82||8.6-12.1%|
|LED||8.7 Watt Screw Base||69-93||10.1-13.6%|
From this table you can see there is a big difference in efficiency between incandescent lamps, fluorescents and LED's. Efficient home lighting ideas stress the importance of using the most energy efficient bulbs possible. However, good design dictates energy efficiency be balanced with good asthetics and reasonable environmental considerations. To this end, we weigh the pros and cons of each type of lighting...
Let's start with incandescents. Although the most inefficient, they offer a soft, asthetically pleasing light with their yellow glow. Due to their inefficiency they will begin to phase out as a result of the Energy Independence and Security Act of 2007. 100 watt bulbs will go in 2012, 75 watters in 2013 and 60's in 2014. Existing bulbs won't be outlawed but replacement bulbs will no longer be available in the U.S.
Quartz halogens offer a brighter whiter light which delivers more lumens per watt than standard tungsten filament bulbs. Energy consumption by bulb is on par with incandescents. The only way energy can be saved with halogens to to use a dimmer or lower the bulb wattage.
Next, consider fluorescents. The advantage is their ability to illuminate large areas efficiently, albeit with a whiter light than incandescents. Fluorescent tubes with magnetic ballasts are being replaced by the T-8 tubes with electronic ballasts.
Small 24" T-8 tubes make great closet or pantry lights and don't hurt the electric bill too much if left on inadvertently. Larger four-bulb fixtures can illuminate a large room quite efficiently. Dimming is possible but may cause flicker at lower settings and requires a dedicated device.
Compact fluorescent (CFL) bulbs showed up about 10 years ago and are gaining in popularity due to the drop in pricing and the energy savings they deliver. This savings is significant as CFL's can deliver the same illumination as an incandescent bulb while using less than one fourth of the energy.
CFL's do have some drawbacks, however. Some are slow to come to full illumination, especially in cool environments such as an attic or a garage. Special ballasts have been designed to compensate for this but add cost to the bulb. Some CFL's are dimmable but most are not. A special CFL dimmer is required.
Of greater concern is the disposal of expired bulbs. Each one contains a trace of mercury, which, over time will create a landfill issue since not everyone will dispose of them properly.
LED's, on the other hand, do not have these environmental issues. They do, however, produce a narrow, focused beam. In the past this has had limited application for area lighting but new, multi-diode LED lamps are changing this. Some LED's are also dimmable but require a special LED dimmer like CFL's.
The biggest drawback to LED's is their high price. Expect to pay $15 to $50 per lamp and up. However, this is offset by extremely long lamp life, (20,000 to 30,000 hours) and very low power consumption. LED pricing has been dropping over the past couple years and is expected to continue. This is partially due to greater demand and higher production rates.
Another factor is that the sapphire based technology in LED's is being replaced with a silicon based technology. Essentially, sand will be used as a key raw material instead of a precious stone. Prices of LED bulbs are expected to be on par with compact fluorescent bulbs in the next several years which will make them the preferred choice amongst most home lighting ideas.
Check out our Incandescent Lighting Comparison page for a quantified comparison between incandescent, halogen, CFL and LED lamps. Use it as a guide to calculate the energy savings for your home lighting ideas.
Before implementing your home lighting ideas we recommend establishing a baseline from which you can measure energy saving improvements. Start by taking an inventory of every light bulb in your home. Record the room, bulb type, wattage and estimated time the bulb is on every day. The Power Panel Profiler is a good tool to use for recording this information.
Use a table lamp connected to a simple plug-in meter to either determine or verify the wattage stamped on the bulb. If you have many bulbs of the same size, such as for a recessed lighting array, just measure a sample and take the average.
Keep in mind that power in watts is comprised of volts multiplied by amps. If the bulb you are measuring is rated at 130 volts and your line voltage is 120 volts the wattage will read slightly lower than the number stamped on the bulb. This translates into lower power consumption and longer bulb life but slightly less illumination.
If you use dimmers, measure power consumption with a similar type dimmer connected between the table lamp and the plug-in meter. Adjust the dimmer to reflect the illumination level normally used in that part of the home.
When you have completed your home lighting list, organize it according to the energy each light set consumes. This should align closely with the run time per day. Start replacing bulbs that run four or more hours per day with a CFL or LED bulb. Then move on to lights that run from two to four hours per day and so forth.
Use our Incandescent Lighting Comparison page for sample calculations that take into account run time, bulb cost, bulb life and energy savings. If you are using our Power Panel Profiler update a new copy and compare it to the baseline to document the savings from your home lighting ideas.