Ventilation

[Tin Falcon]

This subject has been mentioned some in other threads. We all know that various operations performed in the home shop create potential repository hazards. These operations include but are not limited to spaying paint, using cleaning solvents, using cutting oils, dust from grinding sanding, welding etc.
So what do we do about it.
My former allergy specialist would tell me dilution is the solution to pollution. So move fresh air into the shop open a couple of windows.
Another school of thought is remove the potential dust and fumes.
An inexpensive kitchen vent hood that vents to the outside is ideal for this. IIRC regular mild steel painted ones are not expensive and if you can find a dented one marked down so much the better. these are ideal for dedicated paint or welding areas.

Shop around as some come to be vented and many low end ones do not.


The other way to reduce dust and contaminants is collection. A shop vac works well a cyclone separator hooked to a shop vac or dust collector works better. A clean stream HEPA filter in the shop vac either with or without a cyclone unit keeps dust from being blown back into the room.

furnace filters on air inlets keep outdoor dust and pollen out of the shop and out of paint booths.


So a combination of methods is best . collect dust if possible at the source. Put an exhaust hood over areas that produce the most potential hazards like painting and welding and open a window to let fresh air in. And if needed a filter to keep intake air clean.
Tin

 

[robcas631]

I refresh the air as much as possible. I'd like to install a small fan and duct it outside. What I am concerned about is that the fan not spark and... So would you recommend a fan run via a pulley?

 

[Tin Falcon]

If you can find a place that services gas stations they may be willing to sell you the motor from an old gasoline station gas pump the motors are sealed from vapors.
Tin

 

[barnesrickw]

The basement in my old house is not very air tight, but it still don't use things with a lot of VOC's, and my woodworking is done with edged hand tools. Not using table saw, planer or sanding help keep the dust down.

 

[DJP]

I saved an old furnace blower and mounted it in the ceiling of my shop venting to the attic and via soffit vents to the outside. In no time it will extract all of the fumes from welding or any other task that generates bad chemical vapours.

It was free and has become priceless.

 

[Busydad]

A big box fan and an adaptor to hold a thin furnace filter will catch a lot of dust and is inexpensive to make. If you do any spray painting in a furnace room when the furnace comes on you could be in for an explosion...turning the furnace off while spraying is cheap insurance along with a good fan

 

[DJP]

Agreed that flame and spray paint fumes can be very explosive. In the olden days I sprayed a number of cars using enamel and fast reducers. I shut down all electrical equipment and sprayed the floor with water just before painting. The wet floor was sufficient to keep dust from ruining a paint job. Any extraction fan system would have stirred up the dust, in my opinion.

I don't spray cars any more and the furnace blower mounted in the ceiling of my shop is used to vent welding fumes.

Sometimes it's better to just open the big garage doors and let nature clear the shop while I take a break for coffee.

 

[robcas631]

About a month ago I bought some Dykem. When I opened the bottle and applied some on a small piece of brass, I had to evacuate my shop! Nasty stuff! It smelled like someone took a blue permanent marker lit it up and put it out in a vodka bottle. Nasty! So my concern regarding sparks is officially moot and a fan will be installed ASAP.

 

[DJP]

If you are looking for an inexpensive and effective solution to shop ventilation consider using a blower from an old discarded furnace. They are usually free.

I mounted mine on a block wall in my shop and the frame has automotive shock absorber rubber washers for quiet operation.

In very little time welding fumes can be extracted from my (2 car garage) shop. Also of interest may be the interior wall cladding which is galvanized steel panels used for a barn. I mounted the weathered side of the panels towards the vapour barrier and insulation. Lining the entire shop with steel panels adds fire protection and the walls are easy to keep clean.

The used barn siding was also free.

 

[TheFrank]

Thanks 4 the helpful info since im in the process of making the old tactor shed into a 6 car garage w/ a tool/ parts room

 

[gus]

I refresh the air as much as possible. I'd like to install a small fan and duct it outside. What I am concerned about is that the fan not spark and... So would you recommend a fan run via a pulley?

Been building major air compressor packages for Oil Fields. All electric motors and switch gears must be explosion proof. Been using Class 1 Division 1 Group D. Conduits,fittings and cable glands must be ''XP''

For home use, we rarely hit the critical flash level but caution is the key.
When spray painting---------no smoking. No hot electric bulbs and naked heaters.

Vee belts must be anti-static to be XP. ''Anti-static" is clearly marked on vee belts.

Even fine chilli/wheat/corn etc powder and aluminium powder are hazardous with static sparks. Witnessed a controlled explosion demo with aluminium powder and suitable air mixture while attending ''XP" course in switch gears.

Good Luck.

 

[TheFrank]

Do u have a basic diagram for a "home" style compressor?

 

[DJP]

The home workshop needs extraction of fumes more than concern for explosion, in my opinion. Automotive repairs with leaking fuel or large spray painting jobs are the exception and these need all of the precautions taken.

I converted my garage to a workshop where welding and hot cutting oils give off toxic smoke. I can open the big doors and run the furnace blower for quick replacement of air as breathing these fumes over decades is the real risk that I try to mitigate.

However, I am not paranoid about it either. Somedays the fumes actually smell good as they mean real work is underway.

For those who haven't thought about it, consider placing a good sized fire extinguisher at each exit from your shop. At the exit you can decide to go back and fight the fire or flee. At least you will have the option.

 

[gus]

The home workshop needs extraction of fumes more than concern for explosion, in my opinion. Automotive repairs with leaking fuel or large spray painting jobs are the exception and these need all of the precautions taken.

I converted my garage to a workshop where welding and hot cutting oils give off toxic smoke. I can open the big doors and run the furnace blower for quick replacement of air as breathing these fumes over decades is the real risk that I try to mitigate.

However, I am not paranoid about it either. Somedays the fumes actually smell good as they mean real work is underway.

For those who haven't thought about it, consider placing a good sized fire extinguisher at each exit from your shop. At the exit you can decide to go back and fight the fire or flee. At least you will have the option.

Good idea/practice. I have one on the floor next to the work bench where i do silver brazing. Plan to buy a bigger one. While checking spark plug,I did ignite some spilled petrol on the work bench. Fire extinguisher put on mini fire in good time.Bought a replacement.

 

[DJP]

On shelves near work areas where there is potential for a small fire, I keep one litre plastic bottles filled with water. It's easy to reach for one and squeeze out a stream of water where you need it.

The big pressurized extinguishers are placed at the doorways in their holders. I'll only use one in a true emergency as clean up and replacement are added work.

So far only the water bottles have been used for a couple of small surprises.

My wife has an extinguisher in her kitchen and I placed two more at exits from the house just in case. When you start to think about risk mitigation you won't stop at just protecting the workshop.

Another risk of loss is theft. I covered the inside of glass windows with Lexan sheets and installed a latching relay with fire bell for a simple alarm should a door way be breached while we are away. A lifetime collection of tools, machines and toys can become priceless.

 

[AliWay]

So a combination of methods is best . collect dust if possible at the source. Put an exhaust hood over areas that produce the most potential hazards like painting and welding and open a window to let fresh air in. And if needed a filter to keep intake air clean.
Tin

Opening window will allow air into the room but you also allow Pollens, allergens and pollutants into the environment. A controlled and regular fresh air is a key to healthier environment. We had ventilation system that keeps our environment clean, fresh and ventilated. You can have a look on the website to find more about ventilation.
www.ventis.com.au/
:fan:

 

[///]

I work in the oil&gas industry where electrical equipment operated in explosive atmospheres is obviously taken very seriously and is heavily regulated.
In fact, that is exactly my job, I deal with EEHA(Electrical Equipment in Hazardous Areas) every day.

If you must use an exhaust/ventilation fan(can't do the work outside) and you are concerned about arcing/sparking in an atmosphere full of volatiles like solvent or paint fumes, perhaps consider an ATEX or IECEx certified fan/blower. These are designed for oil rigs and petroleum processing facilities and will not cause an explosion.
Beware they are likely to be very expensive, tho this is not always the case. An example of decently priced Ex rated equipment is the Chalmit Protecta series of fluorescent light fittings that can be had for around $200 each.

Keep in mind that many dusts are also explosive and in particular relevance to us, metal dusts! (Grinding/milling) which are categorised as dust group IIIA (combustible flyings)
Seriously, metal dusts are used in some explosives and almost all fireworks. Aluminium is probably the most common! Check out the video below of an aluminium explosion.
Ex equipment is often rated for dusts too.
The equipment not only protects from arcing or sparking, but also from excessive surface temperatures(on motors for example) and typicaly rated for a certain temperature class(maximum surface temperature gain above ambient), you don't need an open flame to cause an explosion!
The autoignition temperature can be very low for some materials. MSDS files for the paint/solvent being used should give a flashpoint and autoignition point (do not confuse the two)
So probably not a good idea to jump on a lathe and take deep curling blue-swarf cuts in a room full of solvent vapour

Not trying to strike fear in anyone, just letting it be known that if you have to work indoors, can't get good natural cross flow ventilation and the possibility of an explosion worries you, safe certified electrical equipment is out there.
http://youtube.com/watch?v=9Ut4hpHxagk