Installing a Skylight Window Insert

This homeowner called Dr. Energy Saver a second time after being so pleased with the prior energy saving work, with the task of making the skylight in the kitchen more energy efficient.

Skylights are often used to bring additional daylight into rooms and are great looking architectural features, but depending on the way in which they were built and installed, they can become a big source of energy waste.

Larry Janesky, owner and president of Dr. Energy Saver, explains the many ways in which energy can be lost through typical skylights that were not built for energy efficiency.

Skylights Can Be A Weak Point

Today we are back at this home that we have worked on in the past. We have air sealed and insulated the attic about a year and a half ago. Then the homeowner had us back to change the old inefficient oil heating system into a high efficiency propane gas heating system with high efficiency air conditioning. Then just last week we were here to inject the walls with foam to add insulation, and you can see the plugs in the walls where we injected the foam. This homeowner isn't going to reside in the house next week, which is why they were left that way otherwise there are other strategies for the holes.

Sealing Skylight

Let's take a look. That skylight, if you come out here on a cold night, you will see that it is a place where lots of heat is being lost out of the building. The glass is very cold and it could even be leaky believe it, or not, without leaking water it could leak air. It is very cold and we are cooling the air inside the room as it touches the cold glass, we are getting a convective loop, feeling some draft as a result. The other problem is in the summer, we have heat blasting in at us through the skylight and we want the light but we don't want the heat. We don't want to add to our air conditioning. We don't want to feel it on our forehead if we are here at the counter and so forth and we don't want it to heat up the house. So, the solution is to install a window at the bottom of the skylight shoot.

Low-E Glass Windows

This is low E glass, in other words, low emissivity glass and it will let light through, but the infrared part of the solar spectrum. The heat won't get through this glass nearly as much, blocking heat flow out of the building in winter, blocking the heat flow in the building in the summer and you can see it is a little bit tinted. We have these two panes of glass filled with argon; so, that we don't get heat transfer from one pane of the glass to the other. In the end, we are going to have a triple layer. We have the skylight and we have two panes of high performance low E glass here and at 6 inches there is a space in the middle. We will dramatically improve the situation, making that the surface of this glass much warmer the bottom surface much warmer in the winter and much cooler in summer.

High Performance Skylight

Okay, so the window fits now. I have to make a trim around there so that the window would go up and sit. The trim is going to have some weather stripping around it and these skylight inserts will help prevent drafts in the winter time when the glass is cold. The air hits the glass and descends and creates a convective loop, but now we have a high performance skylight.

Read Full Transcript:

Hey. I'm Larry Janesky from Dr. Energy Saver. Today we are back at this home that we have worked on in the past. We have air sealed and insulated the attic about a year and a half ago. Then the homeowner had us back to change the old inefficient oil heating system into a high efficiency propane gas heating system with high efficiency air conditioning. Then just last week we were here to inject the walls with foam to add insulation, and you can see the plugs in the walls where we injected the foam. This homeowner isn't going to reside in the house next week, which is why they were left that way otherwise there are other strategies for the holes.

Today, we are here to address a pretty interesting situation. If you have sky lights in your house they are probably a weak point thermally in the top of the house; the glass is very cold and that is the case in this house. Let's take a look. That skylight, if you come out here on a cold night, you will see that it is a place where lots of heat is being lost out of the building. The glass is very cold and it could even be leaky believe it, or not, without leaking water it could leak air. It is very cold and we are cooling the air inside the room as it touches the cold glass, we are getting a convective loop, feeling some draft as a result. The other problem is in the summer, we have heat blasting in at us through the skylight and we want the light but we don't want the heat.

We don't want to add to our air conditioning. We don't want to feel it on our forehead if we are here at the counter and so forth and we don't want it to heat up the house. So, the solution is to install a window at the bottom of the skylight shoot. Now this sky light shoot isn't very tall and we are going to set it up so that there is a space about 6 inches between the skylight glass. Now this is high performance glass. This is low E glass, in other words, low emissivity glass and it will let light through, but the infrared part of the solar spectrum. The heat won't get through this glass nearly as much, blocking heat flow out of the building in winter, blocking the heat flow in the building in the summer and you can see it is a little bit tinted. We have these two panes of glass filled with argon; so, that we don't get heat transfer from one pane of the glass to the other. In the end, we are going to have a triple layer. We have the skylight and we have two panes of high performance low E glass here and at 6 inches there is a space in the middle. We will dramatically improve the situation, making that the surface of this glass much warmer the bottom surface much warmer in the winter and much cooler in summer.

Okay, so the window fits now. I have to make a trim around there so that the window would go up and sit. The trim is going to have some weather stripping around it and these skylight inserts will help prevent drafts in the winter time when the glass is cold. The air hits the glass and descends and creates a convective loop, but now we have a high performance skylight. If you have any home energy conservation need in your home whether it be heating and air conditioning duct work, insulation in the attic in the basement or anywhere in between you like to lower your heating and cooling bills and your electric bills and make your home more comfortable call Dr. Energy Saver.