Finding Air Leaks with a Wizard Stick
A great new tool for home performance diagnostic testing has come onto the market - the Wizard Stick. It's basically a small, handheld theatrical fog machine that uses the same non-toxic fluid as its larger, more prolific brethren.
For the home energy auditor or the home performance contractor, this device provides an effective way to find air leaks and a compelling way to demonstrate them to homeowners. With a Blower Door depressurizing the home, you can walk around with the Wizard Stick, pull the trigger, and watch to see if the smoke just hovers near where it's released or is blown away by air being sucked into the house through a leak.
It makes a nice stream of smoke and produces it quickly when you pull the trigger. Although it doesn't have the neutral buoyancy that chemical smoke puffers have, I haven't noticed that it's far enough away from neutral to be a problem for home energy auditors.
And of course, it has the big advantage of not being toxic. The common chemical smoke puffers available use titanium tetrachloride, which is very corrosive. Several years ago, I kept one of these in a metal locker, and even though it was in a plastic bottle inside a plastic bag, the inside of that locker showed significant corrosion after a short time. I'm happy to find a non-toxic smoke device that works.
In the photo at left, you see me holding the Wizard Stick near an air conditioning vent during a Blower Door test. The air rushing out of the vent (with the AC turned off!) indicates leakage in the duct system, which also counts as infiltration when the AC isn't running.
What makes this story even more interesting to me is that the Wizard Stick has reconnected me with a company from my past. I'm a recovering academic, having taught physics at both the high school and college levels, and one of my favorite places to buy fun physics demonstration products was Educational Innovations. As it turns out, they sell the Wizard Stick for the best price I could find on the web. Check 'em out.
(And while you're there, go ahead and pick up one of my favorites, the Solar Tube, a 60' long black plastic trash bag that floats like a zeppelin when heated by the Sun and becomes a kid magnet when you take it out to a park.)
[Photo at top right from Educational Innovations website.]