Recessed lighting fixtures – aka housings, cans, high hats, or pot lights – are the part of recessed downlights that sit above the ceiling. They provide the structure to attach the wire connections, the trims, and lamps or LEDs. In this post we’ll briefly look at the basics of recessed fixtures including:
- The basic components that make up a recessed light fixture.
- The most common sizes.
- The types of fixtures available including line voltage, low voltage, compact fluorescent, and LED.
- New Construction vs. Remodel fixtures.
- The various ratings that apply to recessed lights and what they mean.
Recessed Light Fixture Components
A recessed light fixture is made up of the following components:
- Housing – The housing (commonly referred to as the can) is the metal container that houses all of the other components. Most are made from aluminum or galvanized steel.
- Junction Box – The metal enclosure where the electrical connections are made to each fixture.
- Socket – The socket is the connector that the lamp screws or plugs into. It can be a threaded base, pin base, or plug depending on the type of fixture being used.
- Thermal Protector – A small safety device wired between the junction box and the socket in all UL listed fixtures designed to turn off the lamp if the fixture gets too hot (usually caused by installing a lamp that uses more power than the fixture is rated for).
- Ballast (fluorescent fixtures only) – Dedicated fluorescent fixtures require an electric ballast to regulate the current flowing to the lamp.
- Driver (Dedicated LED fixtures only) – Dedicated LED fixtures require a driver to regulate the voltage/current flowing to the diode.
- Transformer (Dedicated low-voltage fixtures only) – Low Voltage recessed fixtures use a step-down transformer that converts the incoming 120V line voltage down to either 12 volts or 24 volts.
New Construction vs. Remodel Fixtures
New construction housings are installed prior to the drywall in new construction projects. They have adjustable arms that attach to the ceiling joists. Remodel type housings are used when installing lights in a finished ceiling. Remodel housings use special clips that secure the fixture to the ceiling itself, rather than the ceiling joists. They are designed to be installed from below the ceiling.
The most common residential fixture sizes are 4-inch, 5-inch, and 6-inch. These sizes refer to the diameter of the opening in the housings where the trim fits.
Types of Recessed Light Fixtures
Standard Line Voltage (120V) – The most common type used for general and task lighting. They do not use a transformer, ballast, or driver, which makes them inexpensive and the most trouble-free. Low Voltage (12V or 24V) – Most often used for accent lighting. Their compact lamps allow for a wide variety of adjustable trim options. 12V is the most common. Compact Fluorescent – Commonly used in kitchens and bathrooms, especially in newer homes due to energy efficiency requirements. Each fixture contains an electronic ballast and uses a pin base fluorescent lamp. Dedicated LED – Each LED fixture contains a driver which regulates the current/voltage to the diode. These should be matched with the specific LED modules that they are designed for by the manufacturer. Retrofit LED – These are universal line voltage housings that have a LED plug connector rather than a screw base socket. They are to be used specifically with “LED Retrofit” modules which combine the LED, driver, and trim together as one unit that plugs in to the fixture.
Most Important Fixture Ratings
Ratings labels will be found on the inside of the fixture housing. The following ratings are the most important with regards to energy and safety: IC Rated – An “IC” rated fixture is rated to be installed in direct contact with insulation or other objects inside the ceiling. As a general rule, always use IC rated fixtures in an insulated ceiling. Non-IC Rated – A “Non-IC” rated fixture must have a minimum of 3″ of clearance from insulation on all sides and above. Air Tight Rated – An “Air-Tight” rating on a recessed fixture refers to an energy code first introduced in Washington State which requires recessed fixtures to be manufactured in a way that restricts air leakage (energy loss) through them. Air-tight fixtures prevent energy waste and their overall quality will be better. UL Listed – Underwriters Laboratories (UL) is an independent, non-profit organization that tests and certifies products for safety. While there are similar organization out there, UL is globally recognized as the standard. Using fixtures that are UL listed ensures that they have been tested for safety when installed according to the manufacturer’s instructions. CA Title 24 – California’s Title 24 is an energy code that applies to both residential and nonresidential buildings. Its purpose is to reduce energy consumption. In order for a recessed fixture to be labeled “Title-24 Compliant” it must meet the current efficiency guidelines mandated by the California Energy Commission, which are updated periodically.
If you are pulling a building permit for the installation it is important to note that many states have adopted various energy codes (such as California’s Title 24) that apply in addition to the local building codes. These energy codes restrict the types of light fixtures that you install to ensure that they are energy efficient. Most cities will provide you with a list of the current requirements, but if not it would be a good idea to ask.