steel dustpan to hep prevent distribution of soot and dirt

[micky]

I was reading my furnace manual and I came across this. It says for my upflow furnace, a Carrier 30 y.o. oil burner (no boiler), model

58HV085:

"Upflow models are equipped with steel dustpan to hep prevent distribution of soot and dirt particles through the duct system. "

I though if soot was coming through the ducts, it mean there was a hole in the firewall. If the fire is on the other side of the firewall, how can soot be in the ducts? And what kind of dirt particles are they talking about?

What would the "dustpan" look like or where would it be? I thought I knew all the parts by now.

Thanks.

[RobertMacy]

In our 'sealed' system soot and dark particles came into existence as dust 'burnt' on the hot walls. The stuff actually would streak a clean wall at vents and required periodic cleaning.

[nestork]

I expect that's not soot from the furnace as micky is completely correct; furnaces have heat exchangers whereby the hot flue gas flows through steel tubes and the air being heated flows around those tubes (or vice versa) so the two gas streams don't mix. Any crack in that heat exchanger that allows mixing of those two gas streams requires replacement of the furnace for reasons I don't fully understand.

The stuff that's causing streaks on your walls is likely to be soot particles from cigarettes, burning candles or incense. These soot particles are so tiny that they can float in the air for days.

You'll also find that the most effective way of cleaning that soot off the walls is with a Magic Eraser.

[micky]

I may be right, but surely the Carrier Corporation which actually makes furnaces is right too when they say "Upflow models are equipped with steel dustpan to hep prevent distribution of soot and dirt particles through the duct system. " Don't Carrier and I contradict each other? If so, what is the chance that I'm right?

Their words must mean that without the steel dustpan soot gets sent through the duct system, and "help prevent" is the way it's normally phrased when whatever they're bragging about is not enough to stop something entirely. And they don't even exclude new furnaces, or say some part should be replaced when the soot starts going through the ducts.

It also says a few lines earlier, "No-drip nozzle adapter provides positive fuel cutout to prevent fuel odor and soot problems in the house." No mention of ducts here, but still. Are they only referring to combustion gases escaping through the observation port or the barometric damper? Or do they have the ducts in mind?

[Scott Lurndal]

CO

[TimR]

Any source of consistent air currents will eventually stain a wall. I've seen dark streaks abouve light bulbs, where convection currents from the bulb caused air movements that deposited the dirt.

In a house that burns a lot of Yankee candles or smokers it's much worse, but even without it air blowing on a surface or into a return vent will do it.