Energy Efficient Lighting

Various Light fixtures and the light bulbs, or lamps as we refer to them, vary in their efficiency to produce light.   When selecting a light fixture or lamp you should consider the following:

·        For recessed fixtures Select an I.C.(insulated ceiling) rated housing to allow you to insulate right up to and above the fixture.  If you select a non-I.C. rated fixture the insulation will need to be a minimum of 3” away from the fixture.  Note: this distance is generally for recessed fixtures with incandescent and fluorescent lamps.  (Check manufacturer specifications for the more commercial type fixtures and lamps.)   It is important to realize that if you select non-I.C. recessed light fixtures that your energy bill to cool and heat your house will be higher.  

·        Select recessed fixtures which are considered “air tight” or install gaskets or use calk to eliminate the transfer of air between the conditioned and non conditioned space in the attic or between floors.

·        Does it cost more to buy I.C recessed fixtures?  NO.   Most manufacturers sell the I.C. rated housings for the same as one which is non I.C.  The cost of recessed fixtures varies for other quality reasons, not because they are rated for insulated ceilings.

·        Does it cost more to buy air tight fixtures?  Yes it does, but the cost varies along with the variation of air tightness  that is built into the fixture.  Most manufacturers aim for the goal of meeting the Washington State Energy Code for conserving energy.  The added cost you might pay to meet this standard is a couple of dollars. The selection of the trim affects the air tightness of the fixture and you may have to purchase an inexpensive gasket to reduce the airflow.    High end fixtures are generally built better and are more air tight.

·        Incandescent lamps are very inefficient in their use of energy to produce light.  These lamps produce a good bit of heat which also causes you to use more cooling energy in the summer months.

·        Parabolic or PAR lamps are a more efficient  type incandescent lamp over the standard A-lamp (standard grocery store model) because the lamp includes a parabolic reflector to increase the light output.   Therefore the energy to lumen output efficiency is increased.

·        Flourescent lamps are 3 times as efficient as incandescent lamps.   Fluorescent lamps are made in all shapes and sizes to be used as an alternative to the incandescent lamp.  The drawback is the cost.  A fluorescent lamp requires a ballast to operate.  This increases the cost of a recessed fixture.  Also, the cost of the lamps themselves are about 10 times as costly as an incandescent.  They do, however, last much longer. 

·        Even though they are terribly inefficient, in some situations conventional incandescents are still the best choice. Where you have more illumination than you need but few hours of operation, or other conditions that would rule out a compact fluorescent, you may be able to substitute lower wattage incandescent lamps.

·        For outside or commercial applications, you should consider using other more efficient lamp types.

See the chart below for a comparison of lamp efficiencies

.  Click for larger image

Over time the light output of a lamp decreases. See these Lamp Life charts. 

PEMBA INC considers energy efficiency a major part of lighting design.  Call us to develop your lighting plan.

Contact us at:  504-393-6441

       

email us:

psmith@pembaserv.com