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While replacing an old window with a brand new high efficiency model, Larry Janesky from Dr. Energy Saver demonstrates how to install a replacement window for the best energy efficiency, and explains what a window energy efficiency label means. A window is always the coldest spot in a wall and can feel leaky from heat transfers and the "convective loop." High efficiency replacement windows if installed properly can help your home feel less drafty, save on energy costs, and look great. Understanding the labels and energy efficiency ratings will help you shop and save money with replacement windows.
Hi. I'm Larry Janesky. Happy New Year, it is January 5th. We are here in a very cold day and we are going to replace a window today. This window that we are going to replace is an aluminum frame window and aluminum conducts heat very, very quickly. It is the least energy efficient type of window frame that it is and we have an aluminum window frame, an aluminum window sash and when we shoot these windows with a thermal imaging camera we can see that the frame is desperately cold.
This is the new window that Dr. Energy Saver will be installing today. This window has low E glass. Now low E stands for low emissivity and if we take a look here we can see that what we are going to be doing with the low E glass is reflecting heat while letting visible light through. So only a small fraction of the solar heat will come through the low E glass in the summer time and in the winter time it will reflect heat from the indoors back inside
So this is an energy efficient window. It does qualify for tax credits. It is energy efficient enough to get tax credits .3 or less and if those credits were available in your area and this is going to make a big difference for this homeowner. You know often times people complain of drafts from their windows and that may be true you may have leaky windows but we know that glass is the coldest spot in a wall.
When you replace a whole window you take a frame out and you take the exterior trim out and you put a whole new window in and it has got to be flashed properly at the top at the sides. You got to bring the siding back in and the exterior trim that is replacing a window, but a replacement window is where we have a window like this you would pull the sashes out, pull the stop molding out and slide this in.
Read Full Transcript:
Hi. I'm Larry Janesky. Happy New Year, it is January 5th. We are here in a very cold day and we are going to replace a window today. This window that we are going to replace is an aluminum frame window and aluminum conducts heat very, very quickly. It is the least energy-efficient type of window frame that it is and we have an aluminum window frame, an aluminum window sash and when we shoot these windows with a thermal imaging camera we can see that the frame is desperately cold. I mean really, really cold almost the same temperature as the outside. So very energy inefficient windows but we also have a thermal pane glass here and so we have two panes of glass but the seal somewhere around the perimeter of this glass has failed and air is allowed to get inside in between the glass and when that happens the moisture that is in the air condenses and forms a fog.
You can see there is a fog and water droplets on the inside of this glass very distracting, very ugly from the inside so it is not something that anybody would be happy with. So we also don't have very energy-efficient glass here. This is a clear glass. It is not low E glass. Low E glass has a reflective film on it that will reflect heat in the winter reflects the indoor heat back inside in the summer it reflects the outdoor heat back outside and lets the visible light through the window. We also have an option of Argon filled gas in between the panes of the glass and the Argon will doesn't transmit heat as easily as the air would in between the glass so it makes a more energy-efficient glass itself.
Now we know that a window is the weak spot thermally in a wall assembly. The wall may have Arthur Tyne insulation if properly installed and without air gaps and air leaks and so forth. We have an R-13 wall but a window might only be R-1 or 2. So the window is going to be the coldest spot in the wall assembly. This is the new window that Dr. Energy Saver will be installing today. This window has low E glass.
Now low E stands for low emissivity and if we take a look here we can see that what we are going to be doing with the low E glass is reflecting heat while letting visible light through. So only a small fraction of the solar heat will come through the low E glass in the summer time and in the winter time it will reflect heat from the indoors back inside rather than letting it through as well so there is a coding on the inside of the glass that gives it a little tint that allows that to happen let visible light through but stop the heat, the infrared radiation that part of the solar spectrum from going through the glass. Here is two samples of different glass, now the one on the right is clear glass and the one on the left is low E glass so you can see it is a little bit tinted kind of like sunglasses so we can see that our low E glass is a little bit tinted that is going to give us a big benefit energy efficiency.
We also have another rating called solar heat gain coefficient. This window is .33 the lower the number the better and this measures how well the window is at blocking the heat from the sun. We have a visible transmittable rating that is .56 that lets 56% of the visible light through there and in the process of reflecting heat will also block some of your visible light like sunglasses would, but the important rating is the U-factor on this window and the U-factor measures how overall energy-efficient this window is and this U-value is .3 which is very good, very efficient window. The U-value is the inverse of R-value so if we take .3 and divide it by 1 or into 1 we get 3.33 that is the R-value of this window 3.33.If we had a U-factor of .5 for example then 1 divided by .5 is 2 we have an R-value of 2 so compared to a window with U-factor of .5 this one with a U-factor of .3 we actually have 2/3 better energy efficiency overall with this window compared to a window with a U-factor of .5. We also see that we have Argon gas in between these two panes of glass so the Argon is more energy-efficient.
It is an inert gas that does not allow the heat to be transmitted through that airspace in between the glass so it can go - the heat can go from this glass to the air between the glass to the next pane glass to the inside and vice versa in the winter back out, but the Argon will help prevent that heat flow so that is an option and a characteristic of high-efficiency windows. So this is an energy-efficient window. It does qualify for tax credits. It is energy-efficient enough to get tax credits .3 or less and if those credits were available in your area and this is going to make a big difference for this homeowner. You know often times people complain of drafts from their windows and that may be true you may have leaky windows but we know that glass is the coldest spot in a wall assembly. The glass will always be colder than the wall and so if the glass is cold in the winter we get what we call a converted loop that the warm air in the room touches the glass and it cools down. When the air cools down it sinks and it goes down to the floor, it goes across the floor, up the interior wall where it gets warmed and then it goes down again, and so here we are sitting next to the window and we feel a draft and we think that the window is leaking.
Now again it may be leaking but we also have a converted loop from cold glass and this is why high performance glass in energy-efficient windows is important because if we can keep that glass warmer and it is not so cold we get less of a converted loop. Okay so we have to put this window in and there is a difference between replacing a window and a replacement window. When you replace a whole window you take a frame out and you take the exterior trim out and you put a whole new window in and it has got to be flashed properly at the top at the sides. You got to bring the siding back in and the exterior trim that is replacing a window, but a replacement window is where we have a window like this you would pull the sashes out, pull the stop molding out and slide this unit in to the existing jam.
The frame is set in place. The frame is then shimmed to the proper position. The frame is squared by taking a tape measure and measuring the dimension between the bottom corner and the opposite diagonal upper corner and then we take the same measurement and the other two corners to make sure that they are equal, if they are not equal then we will adjust the frame before we screw it in to make sure that, that frame is square so that the operational sashes will slide without binding and screws are used to hold it securely in place. The shim space around the window is foamed the inside of the frame is caught and the outside of the frame is carefully cocked to make it air tight. Our aluminum will serve to trim the outside of the window and cover the old window frame and we carefully clock that aluminum and make sure that there is going to be no water leaks.
Well there is another job well done by Dr. Energy Saver. If you need windows in your house high efficiency energy efficient windows or if you need insulation or you have rooms that are uncomfortable in the winter time that don't seem to warm up perhaps you may have rooms that are too hot or whole floor the upper floor that is too hot in the summer time and it won't cool down or if you want to just lower your fuel bills you're your electric bills call Dr. Energy Saver, we can help you. Dr. Energy Saver, contact us for a home energy evaluation and written estimate.
