Recessed light
Encyclopedia
A recessed light or downlight (also pot light in Canadian English
, sometimes can light [for canister light] in American English
) is a light fixture
that is installed into a hollow opening in a ceiling
. When installed it appears to have light shining from a hole in the ceiling, concentrating the light in a downward direction as a broad floodlight
or narrow spotlight
.
There are two parts to recessed lights, the trim and housing. The trim is the visible portion of the light. It is the insert that is seen when looking up into the fixture, and also includes the thin lining around the edge of the light. The housing is the fixture itself that is installed inside the ceiling and contains the lamp holder.
, UL
1598 recessed housings generally fall into one of four categories.
The main feature of the housing is designed to ensure that no flammable materials come into contact with the hot lighting fixture. Badly-housed downlights can be a fire hazard, though all newer ones contain a self resetting thermal switch
for safety
.
The housings come in various sizes based on the diameter of the circular opening where the lamp is installed. The most commonly used sizes are 4, 5 and 6 inches in diameter, with 4 inch IC New Construction units less readily available at present. Smaller housings (2 and 3 inch) are also available for specialized uses.
The housing can also be "Air Tight", which means it will not allow air to escape into the ceiling or attic, thus reducing both heating and cooling costs.
IEC
60598 has two classifications.
in black or white, which is the most popular. They are made to absorb extra light and create a crisp architectural appearance. There are cone trims which produce a low-brightness aperture
. Multipliers are offered which are designed to control the omni-directional light from "A" style incandescent light bulb
s and compact fluorescents. Lens trim is designed to provide a diffused light and protect the lamp. Lensed trims are normally found in wet locations.
The luminous trims combine the diffused quality of lensed trim but with an open down light component. Adjustable trim allows for the adjustment of the light whether it is eyeball style, which protrudes from the trim or gimbal ring style, which adjusts inside the recess. These lights allow for full versatility. Lastly, there are the wall-washer trims, which are designed to eliminate the often seen "scalloped light effect".
, MR) contain reflector
s that direct and control the light. Diffuse lamps (A, S, PS, G) control light distribution through their omni-directional light.
Canadian English
Canadian English is the variety of English spoken in Canada. English is the first language, or "mother tongue", of approximately 24 million Canadians , and more than 28 million are fluent in the language...
, sometimes can light [for canister light] in American English
American English
American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
) is a light fixture
Light fixture
A light fixture, light fitting, or luminaire is an electrical device used to create artificial light and/or illumination, by use of an electric lamp...
that is installed into a hollow opening in a ceiling
Ceiling
A ceiling is an overhead interior surface that covers the upper limit of a room. It is generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above....
. When installed it appears to have light shining from a hole in the ceiling, concentrating the light in a downward direction as a broad floodlight
High-intensity discharge lamp
High-intensity discharge lamps are a type of electrical lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with both gas and metal salts. The gas facilitates the...
or narrow spotlight
Searchlight
A searchlight is an apparatus that combines a bright light source with some form of curved reflector or other optics to project a powerful beam of light of approximately parallel rays in a particular direction, usually constructed so that it can be swiveled about.-Military use:The Royal Navy used...
.
There are two parts to recessed lights, the trim and housing. The trim is the visible portion of the light. It is the insert that is seen when looking up into the fixture, and also includes the thin lining around the edge of the light. The housing is the fixture itself that is installed inside the ceiling and contains the lamp holder.
History
The earliest recessed lights were developed in the 1930s by lighting pioneer Ivan Kirlin.Types of housing
In North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, UL
Underwriters Laboratories
Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...
1598 recessed housings generally fall into one of four categories.
- IC or “insulationBuilding insulationbuilding insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...
contact” rated new construction housings are attached to the ceiling supports before the ceiling surface is installed. If the area above the ceiling is accessible these fixtures may also be installed from within the attic space. IC housings must be installed wherever insulation will be in direct contact with the housing. Most IC housings are rated to a 75-watt maximum. - Non-IC rated new construction housings are used in the same situations as the IC rated new construction housings, only they require that there be no contact with insulation and at least 3 in (7.6 cm) spacing from insulation. These housings are typically rated up to 150 watts.
- IC rated remodel housings are used in existing ceilings where insulation will be present and in contact with the fixture.
- Non-IC rated remodel housings are used for existing ceilings where, ideally, no insulation is present. However, these also require that there be no contact with insulation and at least 3 in (7.6 cm) spacing from insulation. Sloped-ceiling housings are available for both insulated and non-insulated ceilings that are vaulted.
The main feature of the housing is designed to ensure that no flammable materials come into contact with the hot lighting fixture. Badly-housed downlights can be a fire hazard, though all newer ones contain a self resetting thermal switch
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
for safety
Safety
Safety is the state of being "safe" , the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational or other types or consequences of failure, damage, error, accidents, harm or any other event which could be...
.
The housings come in various sizes based on the diameter of the circular opening where the lamp is installed. The most commonly used sizes are 4, 5 and 6 inches in diameter, with 4 inch IC New Construction units less readily available at present. Smaller housings (2 and 3 inch) are also available for specialized uses.
The housing can also be "Air Tight", which means it will not allow air to escape into the ceiling or attic, thus reducing both heating and cooling costs.
IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
60598 has two classifications.
- Luminaires for recessing into ceilings with thermal insulating matting covering the luminaire.
- Luminaires for recessing into ceilings but not suitable for covering with thermal insulating material.
Trim styles
Recessed lighting styles have evolved with more manufacturers creating quality trims for a variety of applications. You can find recessed lighting trim with the standard baffleBaffle
Baffle or baffles may refer to:* Baffle , a flow-directing vane or panel in some vessels such as shell and tube heat exchangers, chemical reactors, or static mixers...
in black or white, which is the most popular. They are made to absorb extra light and create a crisp architectural appearance. There are cone trims which produce a low-brightness aperture
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...
. Multipliers are offered which are designed to control the omni-directional light from "A" style incandescent light bulb
Incandescent light bulb
The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...
s and compact fluorescents. Lens trim is designed to provide a diffused light and protect the lamp. Lensed trims are normally found in wet locations.
The luminous trims combine the diffused quality of lensed trim but with an open down light component. Adjustable trim allows for the adjustment of the light whether it is eyeball style, which protrudes from the trim or gimbal ring style, which adjusts inside the recess. These lights allow for full versatility. Lastly, there are the wall-washer trims, which are designed to eliminate the often seen "scalloped light effect".
Lamp types
There are two types of lamps (light bulbs) for recessed lighting: directional and diffuse. Directional lamps (R, BR, PARParabolic aluminized reflector light
A parabolic aluminized reflector lamp is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. Usage includes locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights...
, MR) contain reflector
Reflector
-Science:* Reflector, a device that causes reflection * Reflector , used to control lighting contrast* Reflecting telescope* Reflector , the part of an antenna that reflects radio waves...
s that direct and control the light. Diffuse lamps (A, S, PS, G) control light distribution through their omni-directional light.