What Is Solar Heat Gain?

What Is Solar Heat Gain?

Installing new energy-efficient windows is part of lowering your home’s energy bills and reducing your overall energy footprint. While you’re doing this, you might encounter a few terms you’ve never heard before. Some terms, such as visible transmittance and U-factor, are technical enough that they’re mostly used by experts. Some homeowners, however, may find themselves wondering: What is solar heat gain?

Understanding Solar Heat Gain

Solar heat gain is one of the terms homeowners should become familiar with before installing new energy-efficient windows. Briefly, solar heat gain is the amount of the sun’s energy that turns into heat when it passes through your windows. The details can get complicated, but the principle is similar to that of a greenhouse.

When sunlight falls on your windows, it can either bounce off or pass through. Light that passes through your windows generally falls on the objects inside your home and warms them up. This, in turn, warms up the air in your house. Windows with a low solar heat gain number only let a little of this warming light through, while windows with a high number can let in a lot.

Is Solar Heat Gain Bad for Your Home?

Solar heat gain can be good or bad, depending on what you are trying to do. In winter, a bit of solar heat gain can be great. Early morning sunshine can stream through high-transmission windows and warm up your cold rooms without having to turn on the heat. In summer, however, the same process can have you cranking up the air conditioning even more to deal with the extra heat your windows are letting through.

As a rule, you want to reduce solar heat gain in the warmer months and increase it in the cold season. In areas like Maryland and Northern Virginia, with distinct seasons that run between sweltering summers and snowy winters, both approaches are needed and installations can become complicated.

Ways to Manage Solar Heat Gain

There is no single best way to deal with this phenomenon. Instead, homeowners wondering what is solar heat gain and how can it reduce energy costs can treat their new window installations as an opportunity to retool their energy budget. While it’s certainly not practical to install low-gain windows every spring and replace them with high-gain windows in the fall, a little forethought can go a long way toward managing the natural heating and cooling in each room.

As a rule, the sun sheds the most light on the southern face of your house. It starts in the east and moves west during the day. The sun reaches its highest position in midday, and the highest days are in late June and early July. The sun stays closer to the horizon, at least in the Northern Hemisphere, in late December and early January.

Knowing this, you can plan your window placement to take maximum advantage of solar heat gain. North-facing windows, for instance, generally get little direct sunlight. So a high heat gain coefficient is probably fine on that side of your house. Areas that are often in shadow can be cold even in temperate weather, so a high-gain window helps keep the rooms on the north side of your home warm. Low-gain windows are probably best for the south side of your house, where the most direct sunlight is received.

Making the Most of Solar Heat Gain

Planning your new energy-efficient window installation takes time and research. The expert installers at Thompson Creek have years of experience working with homeowners. We install windows and doors that take advantage of the latest technologies to warm up naturally cold rooms and cool naturally hot ones. Our No Hassle Warranty ensures that any work we do for you is a safe investment in improving your home’s energy efficiency. Contact us today for expert advice or a free estimate on your home energy upgrade