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Air Sealing Recessed Lights from Inside the House

Materials Cost: 1
Difficulty Level: 1

Introduction

Install LED inserts into old recessed can lights to replace inefficient bulbs and air seal the can.

Why

With old recessed can ceiling fixtures, the cans often had many holes for wiring that weren’t sealed and the rims were often not caulked, allowing heat to escape into the attic in winter and hot dusty attic air to come into the home in the summer, wasting energy and making your home uncomfortable. Many older can light models are not rated for insulation contact so attic insulation could not be piled on or around them creating cold spots or hots spots on the ceiling depending on the season and some still have incandescent light bulbs adding to energy losses (Figure 1). If you have a lot of old can lights in your home, one way to fix them is to build boxes over each can light. But that involves building (or buying) the insulation boxes, climbing around in the attic and pushing insulation out of the way to find the can lights and install the boxes, foaming them in place, and then re-installing the insulation. A much easier method that doesn’t involve going into the attic and might achieve more airtight results is to retrofit your ceiling can light fixtures with LED insert kits. These insert kits replace the incandescent lamp with a much more energy-efficient LED light source. The insert fixture is air tight and has an insulating gasket to minimize air leakage. As an added benefit, the LED light source is long lasting, requiring far fewer bulb changes, and the LED produces less heat output as well.

Figure 1. The yellow areas in this infrared camera image show where heat from the attic is entering the home around recessed can light fixtures (Source: Green Building Advisor).

What You'll Need

  • LED retrofit trim kit with a foam gasket
  • Step ladder
  • Eye protection
  • Non-contact voltage tester
  • Caulk and caulk gun
  • Foaming glass cleaner
  • Plastic gloves.

1. Buy an LED retrofit trim kit with a foam gasket.

When shopping for LED retrofit ceiling fixture trim kits, look for fixtures that come with a foam gasket (Figure 2). The foam gasket helps seal the light fixture to prevent air leaks. These LED retrofit trim kits are often available in multi-packs. 

Figure 2. The grey ring around the back of this LED retrofit ceiling fixture trim kit is a foam gasket to air seal the fixture. (Source: PNNL).

2. Turn off the power to the fixture at the light switch.

3. Remove the bulb.

Use a step ladder to remove the existing bulb from the recessed can light fixture. Wear safety glasses to protect your eyes from falling debris. Wear work gloves or wait for the bulb to cool before attempting to remove it. 

4. Test the fixture for power.

Use a non-contact voltage tester to test the fixture to make sure there is no electricity going to the bulb socket (Figure 3). Touch the tip of the voltage tester to the metal in the middle inside of the bulb socket. If the tester beeps, power is still flowing to the fixture. Make sure the wall switch is turned off. If needed, turn off the power to this circuit at the electric panel. Test the socket again and only proceed if no alarm beep sounds.

Figure 3. Remove the bulb from the old recessed can light and test the voltage before inserting a new LED retrofit trim kit (Source: PNNL).

5. Pull the trim down.

Use your fingers and/or a flat-head screwdriver to pry the trim ring loose and pull the ring and the can light down from the ceiling a few inches.

Figure 4. Pull the trim of the recessed ceiling fixture kit down from the ceiling to install the new LED insert kit (Source: PNNL).

6. Disconnect the old can light.

Fully remove the old can light from the housing by squeezing on the two metal spring clips located on each side of the can to disconnect it from the permanent housing, which will stay in the ceiling (Figure 5). Then, disconnect the trim from the bulb socket by squeezing on the clip. 

Figure 5. To remove an old can light from its housing, squeeze the two metal spring clips located on each side of the can to disconnect it from the permanent housing (Source: PNNL).

7. Connect the wire adapter to the bulb socket.

Connect the wire adapter for the new LED retrofit fixture to the old light socket by screwing it into the bulb socket (Figure 6).

Figure 6. When retrofitting an old recessed can fixture, connect the wire adapter for the new LED retrofit fixture to the old light socket by screwing it into the bulb socket (Source: PNNL).

8. Set the light color.

If your LED trim kit has an adjustment allowing you to set the color temperature of the light, set that temperature now: the lower numbers, shown in orange in the photo, indicate a warmer light color; higher numbers, shown in blue, indicate cooler light colors (Figure 7). 

Figure 7. Many LED light fixtures come with a color temperature setting allowing you to set how warm or cool looking you want the light to be (Source: PNNL).

9. Re-attach the spring clips.

If your retrofit kit has sliding adjustments to adjust how far apart the spring clips are, use a screwdriver to adjust those, if necessary (Figure 8). Then squeeze the spring clips to hook them into the brackets in the recessed light housing. Hook the spring clips into the housing on each side of the fixture (Figure 9). Patience may be required to get them aligned in this tight spot.

Figure 8. Some LED retrofit recessed light fixtures include sliding adjustments to adjust the spacing of the spring clips that will hold the new kit in the old can light housing (Source: PNNL).
Figure 9. The spring clips from the new LED retrofit ceiling light kit should attach into the brackets in the original recessed light housing (Source: PNNL).

10. Push the LED trim kit up into place.

Push up on the round trim to slide the trim kit into place. The trim bezel should sit flush to the ceiling (Figure 10).

Figure 10. This new LED retrofit ceiling light kit looks very similar to the old recessed can light fixture but is much more air tight and energy efficient (Source: PNNL).

11. Caulk the trim.

If the trim ring doesn’t sit perfectly flush with the ceiling and a gap is visible, you can caulk the gap to prevent air leakage and improve its appearance (Figure 11). LED trim kit lights last 50,000 hours or more so it will be decades before you’ll need to cut the caulk to replace the light.

Figure 11. Caulk around recessed can and new LED retrofit ceiling light kits to complete the air seal (Source: PNNL).

12. Smooth the caulk.

Here’s a trick for smoothing the caulk to get an even appearance and achieve a very smooth finish. Use foaming glass cleaner if desired to wet the caulk then smooth the caulk bead with a gloved finger (Figure 12). The excess foaming glass cleaner will evaporate on its own and not leave any residue. 

Figure 12. After spraying on foaming glass cleaner, smooth the caulk with a gloved finger to get a neat, even finish (Source: PNNL).

Additional Info

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Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.