My workshop is the back room of my house. I currently have 10 120mm 24v fans mounted on a board sitting on the window sill trying to extract air out of the room.

Unfortunately this doesn't work too well. There doesn't seem to be much air movement in the room. The window is an awning window (hinged at the top) and at times the wind just blows through around the board with the fans.

I'm a little under the weather at the moment because of the sprays and fumes I've inhaled over the last few days. The fans are rated at 100cfm, which I though would be enough, but I assume the static pressure rating of the fans isn't enough (I don't know the SP spec).

The room has one door, one fixed window and one awning window. The door leads back into the house.

Any suggestions on how to improve this?

If you seal the openings around the fans you will likely succeed in making the room have slightly negative pressure in relationship to the outside as you have no means for air to enter the room. For air to flow you need both. 10 fans blowing 100 cfm should be plenty, that's 1 full air exchange a minute for a room 10x10x10. Have the air intake on the opposite side of the room from the fans. Disclaimer: assumes there is no combustion source in the area. Check OSHA for their recommendations on how many times per hour the air should be cycled. Every chemical has a different TLV, some chemicals are so bad you should not ever inhale any of them, cyanoacrylates , and epoxy catalysts are 2 examples as they release cyanide gas. I recommend a good organic vapor respirator if you must use VOCs in that area. Your health, Your family's health is too much to risk for the convienance of doing this indoors.

I would think you would get much better airflow with a regular-old box fan. You can get one at H.D. or Lowes for about $20, or less. If you are painting, I would do that outside, never inside, unless you have a positive airflow mask that gets it air from somewhere suitable for breathing.

You only get 1 chance at your lungs, and life for that matter, make a wise choice here - don't try to save a few $.

Thanks for the advice. For now I've sealed around the fan and that seems to make a difference - my house doesn't smell anymore.

For the record, the smells and chemicals and such come from machining on my lathe and mill/drill. When things get hot they tend to burn off oils and such on the workpiece. I also use WD-40 on aluminium which is pretty awful in my workshop.

Yesterday when I was machining, although there was an obvious flow of air through the door and out the window, smoke generated at my mill still seemed to just waft around the mill, not being drawn away quickly. I'm going to look at installing and exhaust fan or two above the mill and lathe in the ceiling, venting into the roof cavity, and drawing fresh air in from the window.

Not a good idea to vent into the attic space....If you go with vent fans, make sure you vent to the outdoors, NOT to another enclosed space.

sucking in coolant mist. Has anyone tried to use a electrostatic air filter to filtrer out the coolant mist. I wonder if it would work.

If you want to move air from a work shop area, you need a blower - not a fan. A simple fan only produces velocity - but no real pressure.

To make this a bit more obvious - look at the way air is moved around a house with central heat and air conditioning. It uses a blower - not a fan. The reason - it takes both velocity and pressure to move air any distance.

In fact, a blower from a home furnace is a good estimate of what you probably need. Vent to the outdoors - but your general idea of pulling in fresh air from outside - but them vent "through" the roof to the outdoors - seems good. Just don't vent into the attic - that would be really bad.

As far as using electrostatic filters for removing mists - yes - sort of. I use an electrostatic filter in my house for removing fine particles (pollen) but they load up very fast. Once there is even a fine coating on the surface, filtration is actually worse than with a simple filter.

If you want to move air from a work shop area, you need a blower - not a fan. A simple fan only produces velocity - but no real pressure.

To make this a bit more obvious - look at the way air is moved around a house with central heat and air conditioning. It uses a blower - not a fan. The reason - it takes both velocity and pressure to move air any distance.

In fact, a blower from a home furnace is a good estimate of what you probably need. Vent to the outdoors - but your general idea of pulling in fresh air from outside - but them vent "through" the roof to the outdoors - seems good. Just don't vent into the attic - that would be really bad.



As far as using electrostatic filters for removing mists - yes - sort of. I use an electrostatic filter in my house for removing fine particles (pollen) but they load up very fast. Once there is even a fine coating on the surface, filtration is actually worse than with a simple filter.

In the winter time hot moist air in the attic can rot the exposed wood .Take time to exhaust outside.

What I ended up doing, was putting a "whole house fan" in the ceiling, and then a powered attic vent in the roof. The WHF acts as an exhaust fan, and the switch also powers a relay which engages the power attic vent whenever that fan is on.

If you do this, be sure to use the relay or the automatic switching of the attic vent will power the exhaust fan. The relay simply bypasses the thermal switch on the attic vent allowing it to still function properly and no harm if both are closed.