Does Solar Heat Gain Matter When Choosing Windows?

When choosing windows in Northeast Ohio, you want to have:

1) The lowest U-value

2) The highest condensation resistance number

But what people in the north need to think about is Solar Heat Gain Coefficient (SHGC).

Do you have rooms in your home where you spend evening hours? If they get a lot of afternoon sun (typically west- or southwest-facing), you might notice this pattern in summer:

• You always get a glare from the sun.
• You feel uncomfortable when heat from the sun builds up.
• Your air conditioning is working harder, thus costing you more money.
• You end up closing the blinds, and now you are in a dark room and have to turn on the light, costing you more money.

If you’re familiar with this cycle, you might have come across windows that claim to solve your problem. As with most things, it’s not that simple.

This page will take you only a few minutes to read but will save you from getting an inferior product that will not perform. Even if we don’t earn your business, we can help you feel comfortable and confident with your window decision. 

The Glass Demo Game

Salespeople who come into your home are not educated on Solar Heat Gain Coefficient, but they have been educated on using the glass demo.

There are hundreds of window choices, but there are only four glass manufacturers. Every salesperson is trained to do the glass demo. They will set up a heat lamp and line up several pieces of glass (single-pane, dual IGU, an older low-E pane, and their low-E, which is “best” and “exclusive” to their company). They tell you this “exclusive” glass keeps the heat inside your home and saves you money on your heating bills.

What the salespeople aren’t telling you:

• This will be darker than other low-E glass (about 10% or more).
• This glass will not give you any lower U-value than the other low-E glass.
• That they and their company make more money by selling you this “exclusive” glass.

What the glass demo is showing you:

How much of the sun’s energy (heat) is being blocked. This doesn’t help lower your heating bills much, but it can help reduce your cooling cost. This is expressed in Solar Heat Gain Coefficient. A low SHGC means a window transmits less solar heat, which is ideal in summer; a high SHGC means a window collects heat, which can be desirable in winter.

Is SHGC important to someone who lives in Northeast Ohio?

Yes and no. You don’t need it in every window in your home, but it would be beneficial for rooms located on the south or west side of your home, rooms where you spend evening hours during the summer, or rooms that otherwise allow unwanted heat into your home, making you and your family uncomfortable. This is also the room where you have to close the blinds because of the glare on the TV.

The bottom line: Save yourself time and skip the glass demo. If you don’t need a solar control glass product, you don’t need to waste your time with the glass demo.