Smoke Testing Frequently Asked Questions

    1. Why should I have my ductwork smoke tested? 

Answer: Ducts leak...Leakage is invisible....smoking is the only method to adequately identify the leakage to address the failures.

    2.  Is the smoke hazardous to your health?

Answer: No, actually it is not smoke at all, it is theatrical fog...but "fogging ducts" just doesn't sound cool.  Fogging fluid is heated to the vapor point and moved through the duct system at a slight pressure.   We have inhaled the stuff with no effects, however we must confess that we have never drank the fluid straight out of the bottle.

    3. Why isn't it a requirement that all ducts be smoke tested and repaired by the building code?

Answer:  Good question.  Even the AC contractors think that it is a good test because they are called back for complaints, in the summer,  to climb into a 135 degree, unlit attic. Building Officials also realize that this is a superior test compared to plain visual inspection. There are many efficiency programs created by numerous entities with their own fiefdom to protect.  Some are "energy efficient" in name only with little interest in proactively addressing problems.

    4.  Is smoke testing required in other states?

Answer:  California requires smoke testing in change-outs of the HVAC system in certain circumstances, although the process and tools seem cumbersome. The requirement can be found at: http://www.energy.ca.gov/title24/changeout/

    5. Do you smoke test every house that you have contracted for or only random, sampled homes? 

Answer: We do not know how it is possible to address failures by testing only X number out of so many houses.  We cannot understand how an energy efficiency label can be assigned to a home that has never been inspected or tested, as some "energy-efficiency" programs do.  We have a word for this practice: F-R-A-U-D. 

No, we do not sample homes as it is our experience that the number of failures precludes any possibility of sampling. 

    6.   Are duct leaks fixed during smoking of the ductwork or marked with spray paint for the AC contractor to fix later?

Answer: Just marking the failures doe not guarantee that they will be fixed later or that we can even mark the point of leakage adequately. We require an AC representative on-site, during testing, to immediately repair failures in the duct system. 

     7. How do I know if my ducts have been smoke tested and sealed?

Answer: A certificate is issued by a certified duct and smoke tester.  To ensure that the system has been tested and sealed by our protocol, the certificate will be signed by either Bill Eberle or Jon Klongerbo.

    8. What is the expected duct leakage reduction by have a smoke tested performed and failures repaired and how much will be saved in energy costs?

Answer: That would largely depend upon how bad the ducts leaked prior to repairing.  If there was initially very little leakage, then the savings/payback for the test would be longer.  If the the system was very leaky, the payback would be extremely quick.  From our experience, a 30% reduction in leakage can be expected.  Remember, the test and remediation is performed prior to air handler, insulation, drywall and register installation and any other factors.  Even small duct leakages at a long period of time can be significant.

    9. Why don't you smoke the system after all components of the AC system are installed?

Answer: After all components are installed, it is nearly impossible to access what is the major portion of the distribution system for adequate repairs. 

    10.  My builder/AC Contractor claimed that my duct system(s) do not leak, why should I not believe them?

Answer: Trust, but verify.  If they are so sure that there is no leakage, there should be no problem in  verifying the claim. It is a relatively cheap insurance policy that the duct system is smoke tested to be leak-free. In any event, the claim should be questioned, since leakage is invisible even to the best of inspectors.

11. Won't an Infrared camera find duct leaks?

Answer: An infrared depends on a difference of temperature to be of use.  At duct rough-in stage, there is no temperature difference between the air flow created by the smoke testing unit and the outside air.  In addition, the infrared camera would require the operator to give verbal directions to the AC technician of where the leaks are located, even if it was possible to locate the failures.

12. How do you know that the duct system is sealed at rough-in after smoke testing and remediation?

Answer:  When no smoke is detected penetrating the ductwork.