What heats up the house more when the sun shines through it - single pane glass windows or double pane?

Question

We all know double pane glass keeps the heat inside the house better on cold days because of insulation values, but is there a difference between the two when it comes to sunlight shining in? After all, that works on a different physical basis, doesn't it? I'm only asking because I think it's quite handy that the sun heats up the house during the day, but it would be nice if that warmth would then stick around after sunset. It just wouldn't make sense to put in double-glazing to do that if it also means that the sun wouldn't heat up the house anymore.
Any ideas, anyone?
Thanks.

Answer 1

Double pane has argon gas between the plates, acting as additional insulation. Double pane heats the room faster by letting the sun through but then keeping the heat in.

Answer 2

I would think there would be little difference in the amount the house will heat up from the sun regardless of single or double pane windows. Having UV or tinted coatings (which come on some newer windows) might cut down on the warmth. But, as you point out, double pane glass will retain that free warmth longer after the sun goes down.
And if it gets too hot, you can just draw the curtains.

Answer 3

Just about every possible answer has already been given. I would go with a replacement window as there is probably not enough room in your sills to replace a single pane with a double. Also would like to add that you should look into low e glass. The glass is coated on both panes on the inside to reflect energy out (the sun) and reflect energy in (heating or A/C) This is more economical and longer lasting that the older argon filled products. Argon will eventually leak out and become ineffective. It might also be noted that manufactures of argon filled only warranty their products for a short time, usually not even one year.

Answer 4

Ok, bear with me.

Sunlight contains different wavelengths of light, from UV, visible light and infrared. The energy coming through clear glass is mostly IR thru the visibile light range. (Glass is pretty effective blocking UV light.)

When the light enters the room, it heats air molecules, your skin, and is absorbed by any materials or mass. The air will 'store' heat for a short while, but fabrics, carpets, wood floors, etc won't hold much heat at all. A brick or tile floor is excellent at storing heat, as would be large dark-colored containers of water.

A window will permit heat to flow out of the building through various surfaces: the area of the glass, whether the glass has a low-e coating, and the type of frame material (aluminum, wood, vinyl, fiberglas, etc.)

A single pane, uncoated glass in an aluminum frame would have a U-value of 1.3. (U value is a window industry index for heat loss -- high values = worse.)
Aluminum frame, dual pane, uncoated, 1/2" of air space has a U value = 0.75
Vinyl frame, dual pane, uncoated, 1/2" air space: U value = 0.52
Vinyl frame, dual pane, low E glass, 1/2" argon gas: U value = 0.3

Thus, the higher insulating value of a 2-pane, low e glass, argon-filled window would also serve to retain heat much better inside a room, than a single pane window.

Hope this helps

Answer 5

I think the whole idea is about the isolation of the glass itself cause the glass can keep the heat inside ....

If you had a sun outside your house and you want the heat that came into never leaves out to ..... so if you got only a single Pane but with good isolation so it wouldn't leak the heat outside , you would have a warm house ..

But if you even got a triple Pane glass with no sun outside or with no good isolation you would keep cold air from getting inside but you wouldn't get any warmth though ....

Answer 6

If you are looking for solar gain, clear glass in either single or double pane is nearly equal, since clear glass allows for over 90% light transmission, even two panes won't block much light or heat energy. This is good for letting radiant heat in, which means direct sunlight. The insulated glass will better retain your home's ambient heat, which is the air temperature in your home.

Just a note, a lot of newer windows come standard with low-e glass. The easiest way to explain how it works that low-e glass is coated with a micro thin metallic coating. This coating lets visible light through freely, so it is basically invisible. But it acts as a great reflector of heat energy, reflecting heat back to the warmer side. Kind of like a 'one-way mirror' for heat. If it is warmer on the outside, heat is reflected back out, which is good if you are trying to air-condition your home. But if it is warmer inside your home, heat is reflected back in, helping you with winter heat costs.

So if you are looking strictly solar gain, avoid low-e products. And insulated glass will much better keep that heat in when the sun goes down.

Answer 7

We have double pane in our sunroom but it does not heat up that part of the house particularily. However, in some of the other rooms with single pane, it stays warm longer, so I'd say you'd be better off with single. Our double panes in that one room are each 4 X 8' and recently, one window shattered and had to be replaced. $1,000.

Answer 8

You are looking for solar heating...double pane will keep heat in, cold out...but the sunlight must hit something dark to generate heat, and if the dark things are large black containers of water, then you have a heat storage unit as well as a heater...will emit heat at night after sun has set.

Answer 9

A direct answer to your question double glazing has more insulating qualities than single glazing for both keeping heat in the house and reducing the heat from the sun coming into the house. I guess you can say you cannot have it both ways. More people put double glazing in to keep the heat out during the summer than to keep the heat in during the colder months.

Answer 10

Take a car for instance. When the sunlight gets in it heats up the interior. Heat can't get out b/c it changed it's wave length when it was absorbed by the interior mass. When the mass gives off the heat, it can not go through the window because it's a different wave length. The sun is radiant heat, the interior is convection heat. ...trust me, I know these things.