# To those who mechanically ventilate overspray...



## sayn3ver (Jan 9, 2010)

Having possible issues with dry overspray falling on wet trim. Looked at some of the methods used by others on here. 

To those who use the box fan in the window, does drawing the overspray to the one window fudge up said windows' trim (either contamination before you spray it or contamination while it's wet). 

To those who just use a filtered box fan in the room circulating, does it kick up excessive boogers on base (even after a good sweep and vac just walking in the room is going to leave dirt and debris on the floor)?


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## CApainter (Jun 29, 2007)

sayn3ver said:


> Having possible issues with dry overspray falling on wet trim. Looked at some of the methods used by others on here.
> 
> To those who use the box fan in the window, does drawing the overspray to the one window fudge up said windows' trim (either contamination before you spray it or contamination while it's wet).
> 
> To those who just use a filtered box fan in the room circulating, does it kick up excessive boogers on base (even after a good sweep and vac just walking in the room is going to leave dirt and debris on the floor)?



Ideally, you would have a fan and flexible duct, with pre-filter attached to capture much of the over spray before channeling the room air to the outside.


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## Repaint Florida (May 31, 2012)

better threads on here but being the search ucks i did find this
http://www.painttalk.com/f2/powerful-fan-venting-fumes-34945/


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## sayn3ver (Jan 9, 2010)

I've searched and read I think every thread on painttalk about the subject. Id like to do some sort of flex vent to the window but need to spray that window's trim at the same time when doing the room. 

Never plan to use these setups with flammable/combustible products as a disclaimer. 

I've considered filtered box fan in plasticed off doorway with a filter in an open window but would make it inconvenient if I had to leave the room for some reason. 

The solution above also has the same possible issues with contaminating wet trim. 

My thinking is I need the collection to be in the center of the room for trim, right?


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## PACman (Oct 24, 2014)

CApainter said:


> Ideally, you would have a fan and flexible duct, with pre-filter attached to capture much of the over spray before channeling the room air to the outside.


Dude you are on FIRE today with the colors and arrows and stuff!


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## CApainter (Jun 29, 2007)

PACman said:


> Dude you are on FIRE today with the colors and arrows and stuff!


 I'm an artist. I just like taking gratuitous liberty to share my creativity with the community. 

I'm humble like that.


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## CApainter (Jun 29, 2007)

sayn3ver said:


> I've searched and read I think every thread on painttalk about the subject. Id like to do some sort of flex vent to the window but need to spray that window's trim at the same time when doing the room.
> 
> *Never plan to use these setups with flammable/combustible products as a disclaimer.*
> 
> ...


You make a good point about non-explosive equipment when spraying with flammable solvents. Safety First.


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## MurphysPaint (Nov 23, 2015)

sayn3ver said:


> I've searched and read I think every thread on painttalk about the subject. Id like to do some sort of flex vent to the window but need to spray that window's trim at the same time when doing the room.
> 
> 
> 
> ...




Spray the window with the fan last and remove the fan. 


Sent from my iPhone using Tapatalk


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## Epoxy Pro (Oct 7, 2012)

We have tried this unit out with and without the window vent hose run. It worked great both ways. It ate the overspray up and when having to paint windows it's nice not having to move the vent around.

We used it in a basement on a nc job. 2 sprayers going with 3 guns.

http://buildclean.com/


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## Epoxy Pro (Oct 7, 2012)

CApainter said:


> You make a good point about non-explosive equipment when spraying with flammable solvents. Safety First.


Party pooper :jester:


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## sayn3ver (Jan 9, 2010)

cdpainting said:


> We have tried this unit out with and without the window vent hose run. It worked great both ways. It ate the overspray up and when having to paint windows it's nice not having to move the vent around.
> 
> We used it in a basement on a nc job. 2 sprayers going with 3 guns.
> 
> http://buildclean.com/



Pretty steep price. Works well with lighter hvlp spray and wetter airless sprayer? 

Filter replacements are steep too.


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## Epoxy Pro (Oct 7, 2012)

sayn3ver said:


> Pretty steep price. Works well with lighter hvlp spray and wetter airless sprayer?
> 
> Filter replacements are steep too.


It's not cheap by any means I know. The basement we used it in was completely sealed with plastic. Without this running overspray was building up, with it on no signs of overspray lingering. To me it's worth the price. It's not just overspray, dust from sanding, airborn dust, it works great.


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## MurphysPaint (Nov 23, 2015)

cdpainting said:


> It's not cheap by any means I know. The basement we used it in was completely sealed with plastic. Without this running overspray was building up, with it on no signs of overspray lingering. To me it's worth the price. It's not just overspray, dust from sanding, airborn dust, it works great.




Hey cd have you previously used a DIY setup? I'm sure this is more effective, just wondering how much more. how do you feel about the manufacturers claim that it pays for itself in four jobs?


Murph


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## Epoxy Pro (Oct 7, 2012)

MurphysPaint said:


> Hey cd have you previously used a DIY setup? I'm sure this is more effective, just wondering how much more. how do you feel about the manufacturers claim that it pays for itself in four jobs?
> 
> 
> Murph


We have a home made set up in our spray shop. This unit blows ours away.

With the NC job there were other contractors all around us working and with the machine on they all said they couldn't even smell the paint/primer.

NC I can see it paying itself off in a few jobs, owner occupied I guess it depends on the scope of the job (lots of sanding, spraying and so on). With painters I can see it taking more jobs to pay off than like drywall guys or even carpenters.


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## sayn3ver (Jan 9, 2010)

How is it on recirc? Does it kick dust and over spray up?


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## Tonyg (Dec 9, 2007)

I use a dual filter and works fairly well in keeping the overspray /dust down.


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## MurphysPaint (Nov 23, 2015)

Anyone know if it is more efficient having the fan at the beginning or end of the duct run? Ie pushing the air vs pulling the air. 


Murph


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## Mr Smith (Mar 11, 2016)

Tonyg said:


> I use a dual filter and works fairly well in keeping the overspray /dust down.


Great idea! Are the filters on the side of that box? I can't tell.

That pro system is super expensive and I'd imagine that their filters aren't cheap either. I like your idea better and furnace filters are dirt cheap.


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## CApainter (Jun 29, 2007)

MurphysPaint said:


> Anyone know if it is more efficient having the fan at the beginning or end of the duct run? Ie pushing the air vs pulling the air. Murph


Technically, an exhaust fan draws air (negative pressure) rather than supplies air (positive pressure). In terms of where to locate an exhaust fan in a ventilation system, it would have to be after the filters and explosion proof depending on the material sprayed and where it would be located. Like a pneumatic Copus blower for instance.

I believe having an adequate length of ducting in between the fan and the filter helps provide a plenum that can gather a significant volume of air that will help with the draw.

Also, the tighter you keep the room, like closing doors and windows just enough to maintain a little make up air, will provide increased velocity.


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## MurphysPaint (Nov 23, 2015)

cdpainting said:


> We have a home made set up in our spray shop. This unit blows ours away.
> 
> 
> 
> ...





I thought this might be an easy thing to make but I had to look up the definition of plenum. Still don't know what it means lol. Suddenly $1100 doesn't seem so bad... :*(

Can't find any pricing online for the Coppus blowers, which usually means expensive. 


Murph


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## Pete Martin the Painter (Nov 8, 2012)

CApainter said:


> You make a good point about non-explosive equipment when spraying with flammable solvents. Safety First.


I was bored, and reading about a thread that really has no relevence to me except that I like to learn new stuff...and bam..there I am in a kilt!


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## Tonyg (Dec 9, 2007)

Mr Smith said:


> Great idea! Are the filters on the side of that box? I can't tell.
> 
> That pro system is super expensive and I'd imagine that their filters aren't cheap either. I like your idea better and furnace filters are dirt cheap.


Blows into filter and then up through filter. Cheap and doesn't create excessive airflow. I usually have Windows/doors sealed and didn't like the idea of possible overspray or residue on the brick or exterior.


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## MurphysPaint (Nov 23, 2015)

Tonyg said:


> Blows into filter and then up through filter. Cheap and doesn't create excessive airflow. I usually have Windows/doors sealed and didn't like the idea of possible overspray or residue on the brick or exterior.




I was always thinking to put the fan post-filter, how does the fan hold up with the overspray going directly through it?


Murph


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## Tonyg (Dec 9, 2007)

MurphysPaint said:


> I was always thinking to put the fan post-filter, how does the fan hold up with the overspray going directly through it?
> 
> 
> Murph


Used it on a number of jobs and does fine without too much build up. Worse case I'll throw it away and buy another cheap box fan. $12-$15 or so


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## AngieM (Apr 13, 2016)

I apologize for the stupid question, but can you explain why you need the box? Is it just to slow the air so there isn't as much turbulence while spraying?


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## hammerhead (Feb 18, 2014)

http://www.lowes.com/pd/XPOWER-10-Speed-1-500-sq-ft-HEPA-Air-Purifier/50450288

This is what i have. Love it


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## Tonyg (Dec 9, 2007)

AngieM said:


> I apologize for the stupid question, but can you explain why you need the box? Is it just to slow the air so there isn't as much turbulence while spraying?


It blows through two filters and the airflow in the room is minimal if any. And it's way cheap . (Although I would love to have the 1K air filtration)


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## MurphysPaint (Nov 23, 2015)

Recently picked up this little beauty. Used it on a few jobs so far and while it hasn't quite paid for itself yet, I can see it not taking too long. From filtering overspray to clearing drywall dust, it does a mighty fine job. And the two pre filters shown here are only $2 and $8 each respectively. 


Murph


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## lovasnj (May 23, 2015)

What unit is that Murph?


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## MurphysPaint (Nov 23, 2015)

lovasnj said:


> What unit is that Murph?
> 
> 
> Sent from my iPhone using Tapatalk




It's a Dri-Eaz Defendair HEPA 500.

http://www.qcss2000.com/products/dri-eaz-defendair-hepa-500.html



Murph


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## sayn3ver (Jan 9, 2010)

Murph, a couple questions about the Dri-Eaz Defendair HEPA 500.

1) are replacement filter media available locally and or is it readily available? Rough cost for replacements?

2) for overspray purposes only, how often do you replace the pre filters? It would never be used any sort of abatement.

3) what size ducting is used with this machine?


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## MurphysPaint (Nov 23, 2015)

sayn3ver said:


> Murph, a couple questions about the Dri-Eaz Defendair HEPA 500.
> 
> 
> 
> ...



1) replacement filters are really available for me, the tack filter is about $2 and the accordion fleet is about $8. The HEPA filter will cost you $150 but if you keep the pre filters clean you shouldn't have to replace it. 

2) I've used it on two jobs so far. First job was spraying an industrial ceiling in a residence and I used 3 sets of pre filters. Tons of overspray because of the steel web joists. (See my original photo). Second job was a basement reno, about 1,000 sq ft and I used 2 sets although I probably could have gotten away with 1 (just being cautious with the HEPA). It cleaned the drywall dust out of the air as we wiped the walls and I spray primed the whole basement and sprayed the ceiling, trim and doors. Was able to take my mask off within 10 minutes of finishing with the sprayer. 

3) 12" input 8" output 



Murph


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## sayn3ver (Jan 9, 2010)

Not being a cheapo but just curious

Are the prefilters a dimension that one could use a furnace filter in a pinch?

I don't mind buying the appropriate media but sometimes you find yourself in a jam and if the device takes proprietary filters only it makes the system less appealing. 

For example. I have a much older fein turbo vac ii. I retro'd on one of those cleanstream gortex filters and it can use rigid/shop vac bags. I use this for general clean up. 

My newer festool CT midi takes festool bags only. I'm stuck ordering online or there is one paint store somewhat close by that stocks them, however they don't have the hours that the box stores have so it's less convenient. I use the midi for dust pickup only despite the festool bags being a little cheaper than the rigid ones at home depot. Not because of cost but if I get into general clean up and start burning through bags i know I can always go and get more with the fein. Does that make sense?


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## MurphysPaint (Nov 23, 2015)

sayn3ver said:


> Not being a cheapo but just curious
> 
> 
> 
> ...




The filters are spec'd 16x16". I bought them by the box so I have a small inventory of them, and will order more now that I'm starting to get a feel for how long they last. They simply rest in behind the intake cover, so there isn't anything proprietary about them.


Murph


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## sayn3ver (Jan 9, 2010)

That's good to know. 

Off topic sort of but I purchased a European made erv (energy recovery ventilator) for my personal home. Didn't realize until after that I'm stuck ordering filters online because they are not any size or thickness that is offered locally. 

That's all I was getting at with my question. I wasn't sure how they were installed in the unit.


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