# An alternate approach



## ducbsa (Jul 6, 2014)

I'll keep my DC for now, but his filter boxes are interesting. I'm not sure where I'd get a used water heater fan, other than pestering plumbers to let me take them off old heaters before they are taken to the landfill/recycling.


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## GeorgeC (Jul 30, 2008)

Nice too see someone be inventive. However, I do not think his invention is very useful.

How many of us have a strip sander? Plus, a strip sander does not produce very much dust to begin with. I guess for machines that really do produce dust you built bigger and bigger individual machines with bigger blowers.

George


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## Steve Neul (Sep 2, 2011)

I for one have never seen a fan on a water heater. Still the impellers were designed for clean air. I think they would get stopped up with dust.


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## Jim Frye (Aug 24, 2016)

Direct vent water heaters use a small squirrel cage fan for venting the combustion gasses out. The're called "Inducer Fans" and are also used on high efficiency furnaces. I doubt they have enough CFM for true equipment dust collection. My shop built ambient air filter is built around a cast off HVAC air handler attached to a plywood plenum box for output to two vents. The front of the air handler box had room for a 4" thick pleated filter and I use cast off filters from a computer room. You can now buy 4" thick filters readily.

One added thought. I had to replace the inducer fan on a water heater at our old home. The blower fan came apart and the unit was sealed, so a replacement was the only recourse. The replacement unit was $400 at a wholesale distributor, so this solution would really have to use a cast off fan to be economically worth trying.


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## Catpower (Jan 11, 2016)

Jim beat me to it, I was typing and hit a wrong button LOL

The inducer fans will put out about 80 CFM before going through a filter, the filter will keep the forward curved blower clean so that wouldn't be a problem, but 80 CFM isn't much air

And he is right 3M Filtrete are so dense they are worse than leaving a dirty filter in the system, they have ruined many compressors on a/c units, should be outlawed but people think they are getting better because of perceived value, it costs more so it has to be better

Jim, and everyone else, if you use pleated filters as long as they don't get wet you can blow them out with compressed air to get several lifetimes out of one, although if you are spraying finish while air is drwan through the filter, it is shot, the finish sticks to the filter


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## ducbsa (Jul 6, 2014)

Larger water heaters seem to have the fans:

https://www.homedepot.com/p/Rheem-Performance-75-Gal-Tall-6-Year-76-000-BTU-Natural-Gas-Power-Vent-Water-Heater-XG75T06PV76U0/205811179


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## Steve Neul (Sep 2, 2011)

ducbsa said:


> Larger water heaters seem to have the fans:
> 
> https://www.homedepot.com/p/Rheem-P...wer-Vent-Water-Heater-XG75T06PV76U0/205811179


Gees, that price is probably why I've never seen one. Most of the time when I've seen people needing more hot water they have two water heaters, sometimes side by side.


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## sanchez (Feb 18, 2010)

I have one of those, but only an $900, 50 gallon. This type of gas water heater is used when you don't have a chimney.


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## Pineknot_86 (Feb 19, 2016)

The fans do double duty- they exhaust the combustion gasses out the flue plus they act as a booster to deliver more air/oxygen to the gas burner, increasing efficiency. We called them a "power burner."


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