Monday, October 5th, 2015 by Ben Kershner
Smoke and Mirrors: It’s not all smoke and mirrors.
I carry quite a few tools with me when I head out to assess a home with comfort issues. I use different tools to gather data and put together picture of exactly what’s happening in a home, and WHY this room is colder than that other room. Fixing a comfort problem isn’t like fixing a plumbing leak. The forces involved may well be completely invisible.
A thermal imaging camera uses infrared light to visually represent surface temperatures. When you can “see” the wall temperatures, you can identify where the insulation is, and where cold air is leaking in. It’s a great tool that can tell us how close a surface is to the outside temperatures – and therefore how much of a problem that part of the house might be.
A smoke-tool produces a neutrally-buoyant smoke, which can be used to identify air-currents. The smoke lets you “see” the air. You can use a smoke tool to identify exactly where that draft is coming from. Most people are more likely to notice a cold draft of air coming IN, rather than a draft of warm air leaking OUT. If the smoke is being sucked into a recessed light-fixture, then we know that air can follow that path.
A blower-door is a big fan that fits in the front-door of your house. By moving large volumes of air, we can exaggerate the minor drafts to make them easier to identify. We can also quantify exactly how much air-leakage the house has overall, to give us a big-picture idea of the total draftiness of a home.
We also carry anemometers, hygrometers, psychrometers, manometers, gas-leak detectors, combustion analyzers, and more.
The real magic starts, however, when we use multiple tools together. If the blower-door is pulling cold air down into the wall cavities, following the path of a light-switch wire, then the drywall is going to get cold. The thermal camera will show that coldness seeping down the wall. The smoke tool will show the air jetting out of the light-switch.
I use a mirror to identify water heater exhaust fumes spilling out of the exhaust pipe. The humid fumes produce condensation on the mirror, clearly showing me what’s going on.
It’s possible to quote a solution based on “I’ve seen something like this before, so THIS is probably the right answer because it’s worked in the past.” But I won’t do it. With the right tools, I can identify EXACTLY what the problem is, and not make any guesses. Albert Einstein supposedly said, “If I had an hour to solve a problem I'd spend 55 minutes defining the problem and 5 minutes thinking about solutions.” While the origin of the quote may be dubious, that’s a great way to approach your home comfort issues. Don’t start with, “I need insulation.” Start with determining exactly WHY, WHAT, WHEN and WHERE the problem is. That makes it easy to determine the best HOW for the job.