Seal It Up!
There is a hole in your house. And it’s huge. Just because you don’t see it doesn’t mean it’s not there. It’s hiding in plain sight.
The average home has a “hole” the size of a hula-hoop through which outside air (and bugs) enter -- all day, every day. It’s not one giant gaping wound, but the aggregate of all the tiny cracks and gaps -- around plumbing, electrical outlets, doors and windows, you name it. And, all those tiny spaces add up.
Air sealing allows for better heating/cooling and humidity control, reduces the presence of pollen, mold, dust and insects, and makes for a quieter environment. It’s one of the most important things you can do to immediately reduce your energy bill. And, it has the potential to do more for the planet than even, say, electric vehicles -- it’s that significant.
Air sealing works by addressing a couple major issues.
The first is called the “stack” effect, in which warm and cool “stacks” of air seek equilibrium. During the summer months, a leaky home sucks warm air in and expels what’s cool due to the difference in indoor/outdoor air pressure. In winter months, the effect reverses: warm air escapes as cool air comes in.
Air sealing prevents the phenomenon from happening and, as a result, makes heating/cooling your home a whole lot easier.
The second principle is the “windbreaker” effect. Insulation is meant to work with air sealing the same way a wool sweater does with a windbreaker.
The wool sweater (insulation) retains heat but does nothing to stop cold wind from piercing through. A windbreaker (air sealing) keeps cold air out. Separately, they only work partially; together, they’re an unbeatable duo.
Finding the holes: an energy audit
If you’re unsure where to start, or even where your leaks are, our Magenta House Squad is here to help you start with a home energy audit. If you need even more help, LADWP offers this service for free. Other power companies may charge up to $150 for an average, one-story home.
During an audit with a pro, expect a blower door test. The professional will attach a specialized fan-door to your front door and depressurize the house. The exam (it’s fun to see it in action) checks for a house’s air flow and catches air leakages your naked eye can’t see.
The optimal leakage rate is 0.35 air changes per hour, meaning that your house will fully exchange its air every three and a half hours. Very leaky homes can filter at a rate three times that much.
It is also possible for your home to be too tight and leak at a slower rate. That can easily be fixed with a ventilation system.
Doing the work
A significant amount of airing sealing work is something you might likely be able to do yourself or with the family (with kids, then of course only with adult supervision). Major areas to check out include windows, doors, attic openings, basement openings, chimney, ceiling lights, light switches, outlet boxes, air ducts, ceiling fixtures, rim joists, flooring, and plumbing.
Spray foam is used to help seal areas around pipes, plumbing, sills, framing, duct work, wall joints, electrical outlets, and gas penetrations, as well as siding. Rigid foam is used for exterior walls, foundation, and roof.
Caulk is for sealing cracks and gaps less than a quarter inch wide and around plumbing fixtures. Metal flashing is for chimney sealing, primarily. Weather stripping is for windows and doors.
Professional help may be especially helpful in attic and under-floor areas.
Finally (or rather, first and foremost), don’t do dumb stuff! When you’re sealing around outlet boxes or anything electrical, make sure the power is entirely switched off before doing any work and follow all the pertinent safety rules and regulations. No shortcuts. Not worth it.
Go here for a free, online list of common home areas you’ll want to check and fix.
Click here for a free, downloadable guide to DIY sealing courteous of the LADWP.
Learn more ways to save on power with LADWP.
Learn more about the assumptions behind Magenta House water and power savings calculations.
DETAILS
Upgrade: Air sealing
Goal: Reduce the gaps in your house or apartment.
Potential Savings*: 1,700 KWH (kilowatt-hours)/yr, $200/yr.
Skill level: ★★☆
SAVINGS*
The average home savings calculation is based on the usage needs of a family of four.
Costs vary greatly depending on the improvements you make. But expect savings to amount to something like 1,700 KWH, or $200, or even much more if you really try to get things tight.
