Any HVAC folks out there?

[Matthew]

I'm looking for ideas on what to use for testing house HVAC ductwork for leaks. I don't need a whole pressure testing system, just a small smoke generator. I've found a couple for mail order - some use glycol, some use a wick or other chemical reaction of some sort. Any other ideas, like a puffer-type bottle of powder?

This is for a DIY project, not a serious contractor-level job.

 

[wabower]

Won't the leaks be found at the connections and joints? Mine were. On a hot day, you can feel the cool air leaking out and get pretty close.

I'm looking for ideas on what to use for testing house HVAC ductwork for leaks. I don't need a whole pressure testing system, just a small smoke generator. I've found a couple for mail order - some use glycol, some use a wick or other chemical reaction of some sort. Any other ideas, like a puffer-type bottle of powder?

This is for a DIY project, not a serious contractor-level job.

 

[AggieMike88]

Spritz bottle with soapy water? Spray on surface and look for bubbles?

 

[Matthew]

Won't the leaks be found at the connections and joints? Mine were. On a hot day, you can feel the cool air leaking out and get pretty close.

Yeah - those are the obvious ones. My HVAC guy uses a thing that looks like a BBQ/fireplace butane lighter. It emits a nice, visible stream of non-toxic smoke. I found one on-line for about $30 (I'll probably call him and see if I can find one locally).

That smoker shows pretty well that I have a negative pressure in the basement when the furnace blower is on. The basement door was open about 4" - he stood next to it and that smoke got sucked right through the opening. I'd never be able to feel that draft, but the smoke made it obvious. There are also openings in wall cavities where ductwork and furnace and water heater flues travel from the basement up to the attic. Smoke also shows air movement there, too. Not enough to feel, but pretty obvious when you can see it. I really don't want to seal up the house as much as my HVAC guy wants to ("this house should be so tight that when your kid passes gas it lingers for a week"), but I do want to do what I can to increase the efficiency of the furnace/AC and that means sealing up what I can so the system uses the cold-air returns like it should, instead of getting the cold-air return from wherever. On the pressurized (conditioned) side, I can take care of that just by feeling for drafts around seams.