You’ve decided to pursue a solar home improvement, but aren’t so
keen on the idea of putting panels on your roof. No worries, you
just need to understand the concept of gain.
I Gotta Gain Some Heat
I’ll cut to the chase – gain refers to how you generate heat for
your home without solar panels. You can think of it as gaining
heat by manipulating the power of the sun. There are three
categories of gain: direct gain, indirect gain and isolated
gain. So much for the mumbo jumbo, what are we really talking
Direct gain refers to improving your house in a manner that
allows the sun to…[drum roll]…directly provide power in the
form of heat to your home. For instance, if you install large
windows in the south facing side of your home and put down heat
storing flooring such as masonry, you are pursuing direct gain.
The sun will directly heat the home through the windows during
the day and will also heat up the flooring. As the sun goes
down, the flooring will continue to radiate heat. The advantage
of direct gain is it is fairly easy to implement. The
disadvantage is it only works during the day and for a few hours
afterwards if you’ve put in a heat storing flooring material.
Indirect gain is a bit more complicated. It refers to the idea
of using a structure between the exterior and interior of the
house to store heat produced by exposure to sunlight. The basic
idea is to get more heat production for a longer period of time.
Indirect gain is typically accomplished by building a thermal
wall out of masonry, known as a Trombe Wall, as the south facing
wall of your home or a part of it. The wall is built out of a
material that absorbs heat such as concrete or brick and then
has glass placed over it. Put another way, the south wall is a
window with a brick wall behind it. The wall materials suck up
the power of the sun and store heat. This heat is then radiated
when you need it by opening vents in the wall. The advantage of
indirect gain is you get longer, more controlled heating. The
disadvantage is you have the world’s weirdest looking window on
the south side of your home.
Isolated gain is a simple concept. Have you ever used a
greenhouse to grow flowers or tomatoes or…well, something?
Isolated gain works just like a greenhouse, except you are
providing heat to yourself instead of plants. Essentially, you
build a self-contained glass structure on the south side of your
home which is also well insulated. The structure heats up in the
sun during the day to very high temperatures. When you need
heat, you just turn on a fan, which moves it into the house
through venting you’ve installed.
The beauty of any of these systems is they are fairly simple
concepts to understand. If solar panels don’t appeal to you,
just go for some gain.