Importance of Sealing Around Can Lights
We talk a lot about air sealing and how important it is and today I would like to focus on one area that causes a lot of trouble and that’s recessed lighting. Recessed lights, also called can lights or hi-hat or eyeballs, come in a variety of shapes, styles and trim. They are mounted up in the ceiling and with a very clean, flush profile to them so they look great. The challenge is the way these are installed in your ceiling. They create huge bypasses for air allowing warm air to escape up out of your house in the winter. If you have pressures and balances the wind actually allow either cold air to get into your attic or warm air from your attic to get down into the house. In the summer you don’t want any of that.
Finding The Air Leakage
What we like to do would go in and use a blower door to help find the air leaks in the home. We pressurize the house and we’ll go around to all the recess lights and try to evaluate how much it’s an issue. When we have the blower door depressurizing the house, we can use our hand or a smoke stick to actually feel or see air movement. Air is coming in, rushing around these lights into your home through your attic from your ceiling space. After we do the blower door in our inspection inside the house, we also like to pop up into the attic that will also give us a lot of clues. Sometimes you can see the lights from below leaking up in the attic. Of course that means there’s openings between the attic and your house.
A very good sign is dirty insulation around not just recessed lights but any hole. Dirty insulation is a sign that a lot of air from your house is leaking up through the holes in the attic. It’s actually being filtered or cleaned by the insulation before the air escapes outside. You actually are using your attic as an air filter to clean the air that’s leaving your house.
How to Stop The Air Leakage
After we’ve identified the problems we send our crews up. They pull back any insulation if it’s there already. They will seal around the fixture. Now this is something that homeowners can do themselves but you have to be very careful. There are different types of lighting fixtures. You need to know what it is, some fixtures cannot have any insulation contacting them. They risk overheating and causing a fire. Others are called insulation contact or IC rated. These can actually have insulation contact with them.
In existing homes we find a lot of very leaky non-IC rated fixtures that means we can’t have insulation contact. We like to build a box around the fixture. Air seal that box to the ceiling plane. This provides an airspace around the fixture, it’s airtight so air will not leak through it. This gives us an opportunity come back and insulate right up to that box and over the box. This gives you a nice even blanket insulation in your attic.
Choose the Right Type of Can Light
When you are thinking about recessed can lights, there’s another energy opportunity to think about. Most recessed lighting was originally installed as incandescent or halogen. These are not very energy efficient, they generate a lot of heat. In the summer, you can think of these recessed lights as mini heaters all throughout your house. These lights are heating your house, your air conditioner turns on to cool the housing essentially the two are battling each other. This wastes an enormous amount of electricity. First the lights themselves are an inefficient way to light your home. They create excess heat now your air conditioner has to remove that heat.
Where we have an appropriate solution replace those incandescent or halogen bulbs with either compact fluorescent or there are now pretty nice LED recessed fixtures available. Don’t buy the cheap ones that the big box store sell. You want the right fixture to give you the right light fully dimmable.
Test Air Flow Through The Home
Of course anytime you alter your home whether you be adding an addition or replacing windows or in this case air sealing round recessed can lights it’s important to test out and check combustion safety of any appliances you may have from a furnace or hot water heaters. Make sure that they are venting properly after we impact the dynamics of airflow in the house. Things change. It is really important to have a qualified contractor or utility professional who knows what they’re doing check out these appliances.
Recessed lighting can be a really good design choice and make a lot of sense in my home if you pay attention to the details. Choose the right efficient lights and make sure you air seal around the fixtures so you’re not losing energy unnecessary. If you’ve got an existing home with recessed lighting there are
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