During the winter, as I look around, houses yell out to me. Do they speak to you?
Look at this photo. It’s a beautiful day after a light snowfall. Half of the roof has virgin snow. The other half is totally melted. Clearly, the melted side is losing energy compared with the other side.
This winter, I encourage you to look at your roof after a cold night. If some of the roof is covered with frost or snow and some isn’t, ask yourself why? Sometimes, you’ll think that it’s the Sun melting the snow, but this photo is a perfect example. The roof faces south and gets lots of sun. Half isn’t melted, so obviously, it’s NOT the sun melting the snow.
Usually, its not quite as obvious as shown here. Instead, you might have strips or spots of missing snow. Even so, that translates into lots of wasted energy.
Check out your attic. Give it a good look. How could heat be getting up there?
Sometimes, the problems are obvious. You might see big areas missing insulation, like this one. Remember, the details really matter. Insulation has to be placed into these cavities nice and evenly, with no gaps. Any place air can go, you’re going to lose heat.
But some problems are not quite so obvious. See the gap in the ceiling where the wires are going through and the right wall, where there’s a big gap leading down the wall? These areas may be stealing as much energy as the missing insulation. In fact, often, hot air leaking from the living space is even worse than missing insulation.
If you have areas like this, you want to air-seal them before adding insulation. Big gaps like this can be filled with spray foam. Be be warned – some foams expand like crazy, and if you’re not careful, they can bulge walls or even break the sheet-rock. You want to be careful and use spray foam conservatively. Get to know how much and how long it expands.
For larger gaps, you can also use plastic bags filled with insulation, creating a “pillow” that can be shoved tightly into these spaces. The key thing is that you want it as air-tight as possible. This insulates and air seals spaces. But it also helps reduce the spread of fire. Fire travels through gaps where air flows, so if you have a big open cavity, the fire will travel right up through it. If you block the cavity, the fire is much less likely to spread that way.
How much of a difference does missing insulation make? A lot! A typical attic in cold climates should have at least R-40 insulation. The 40 tells you that it blocks 40 times as much heat loss as something with R-1, which is about what the bare ceiling is. So if you have ten square foot of missing insulation, like shown above, that little area loses at least as much energy as four-hundred(!) square feet of properly insulated ceiling. That’s huge! When you add in the energy lost through big gaps, this relatively small area of attic could be doubling the heat loss to the attic in the winter. In the summer, the rooms below will be baking hot. So it really pays to properly insulate and air seal.
Some energy holes are less obvious.
Recessed lights are a big source of wasted energy AND a cause of attic mold and humidity problems.
Older recessed lights are supposed to have no combustible materials within three inches all around. Notice how this one is installed, right adjacent to the wood. Not only is this missing insulation, it might be a fire hazard. Think of the beating that wood is taking from a hot light bulb burning next to it, hour after hour.
Most homes with recessed lights have more than a single fixture. Usually every room has a couple or many fixtures. Each one is wasting energy through air leaks and heat loss. So if you have recessed lights, you’re sure to be wasting energy.
If the fixtures are “IC” rated (IC = insulation contact), then you can actually insulate right up to the fixture. Otherwise, you might want to make a fireproof box out of sheet-rock, and fit it around the fixture. Then insulate around the box. In any case, you don’t want the situation shown in the photo above. Remember the 40 to 1 ratio of uninsulated ceiling energy loss compared with insulated ceiling. Open your eyes!
Until you know about them, recessed lights may not be obvious. But detached ducts are really obvious energy holes. I can’t tell you how many attics I’ve gone into and seen detached or missing ducts. Each of these are probably wasting 10% or more of the entire heat produced by the heating system. It’s literally criminal to let things like this go on.
Look around at your ductwork. Pull gently on it. Properly installed ductwork can take a lot of pressure before the ducts fall off like shown here. Improperly installed ducts will fall off as soon as the system comes on.
In this photo, the ducts have been improperly attached and the ducts are really leaky. Look at the big gap near the inside corner of the sheet metal. If this one section of ducts is this bad, just how bad is the other hundred feet of duct? This person was probably losing half their heating and air conditioning in their attic due to missing and improperly installed ducts!
Open your eyes
Energy auditing is often simply about opening your eyes and looking. Once you know what to look for, you’ll see energy leaks all over. Some obvious, some obscure. But if you’re observant, you should be able to find the big energy holes in your home. And if you’re lucky, you can reduce your energy bills substantially by just spending a few hours in your attic.