Visualizing air currents is a critical part of building analysis. If you can see the airflows, you can often determine what's working and what isn't. You can use a mirror for combustion analysis, but seeing a trail of smoke sucked in under the draft diverter is a clear indication that there is no spillage. You can use a manometer to set up the doors for worst case, watching a trail of smoke is quicker.
The Retrotec AC107 smoke stick has been the tool of choice, but shipping regulations has made them difficult to get. I am curious to know what other air current indicators people are using for testing and diagnostics.
I've used the "Wizard Stick" from time to time. It's a fog generator that is essentially a kids toy, so non-toxic and is easy to use. Not sure how rugged it is, but might be worth checking out and trying:
We carry a variety of smoke puffers but I know the Retrotec puffer was the most popular. We still have some left but due to the new Hazmat regulations we most likely won't be able to carry them much longer. The Wizard Stick that Matt mentioned below and the Bottle Puffer made by The Energy Conservatory other 2 comparable puffers, one downfall is the mixing of chemicals. We also have smoke machines (Rosco 900) for bigger jobs. Let us know if you hear of anything else comparable, we'll be happy to hunt it down for you!
Tracy & Matt
I find the Wizard Stick easier to use than the Puffer. It puts out a lot more "smoke". Both have problems: constant lancing of the Puffer outlet and if you are not carefull about draining the Wizard Stick, the toy train smoke fluid used gets on everything in your bag. A good source for the Wizard Stick is Pow Science on the web.
Has anyone had experience with the Dragon Puffer? It's more professional looking version of the Wizard Stick and also comes in a kit...
Paul ... the Wizard Stick is produced by folks that seem really concerned about the performance of their products ... I have been in touch with them a few times ... but I'll be damned if I can get that thing to work ... I have a couple & they always seem to fail as I'm walking the client through ...
I use a smoke pen. It is great for draft, duct leakage, and general air leakage ID. The one drawback is that it smells like somthing is burning becasue it uses a a wick that is buring while giving off a steady stream of non-toxic smoke. I personally like it and get great photo documentation specifically of return duct leaks. This can be purchased from Grainger
Thanks for writing all of the tools-of-the-trade articles. A big help for many folks.
I just switched from the Wizard Stick to the Dragon Puffer. Both use food-safe theatrical fog fluid and were invented by Joel and Alan Aronie of Zero Toys in Concord, MA. I believe the Smoke Pencil is a rebranded Dragon Puffer. As others have said, be sure to keep the unit upright, and don't over-pump the fluid.
I have used the Retrotec product, but didn't like getting even an occasional inadvertent whiff. The MSDS info convinced me to switch. I do like that it can have any orientation and it was easy to regulate the amount of smoke generated.
To me, the talcum powder type puffer was an unimpressive performer for light air movement. And it can't be used while pointing down.
The Björnax Smoke Pen imported from Sweden by Regin works well despite being a heat-buoyant smoke, but it is difficult to regulate the amount of smoke generated. It also creates ionized particles from burning a stearic acid impregnated cotton wick which can more easily trigger smoke alarms than the foggers.
The foggers are non-ionizing and are less likely to set off smoke detectors unless they are the more expensive optical sensing smoke detectors.
One of the best working battery-driven theatrical fog generators is the Tiny Compact Fogger C07 by Look Solutions. Works well if a lot of fog is needed for just a 1 second or more burst of fog, but a bit much for checking combustion appliance draft. And at $1850, it is not cheap. It's cousin, the F07, is perfect for remote triggering in ductwork.
Paul reviewed some of the most common smoke puffers in an article that will be published in the May/June 2012 Home Energy Magazine. Check it out, as well as Paul's other articles in the Home Energy "Tools of the Trade" column series. Great series IMHO.