engine room vent.

This should be a quick one. I did a search and couldn't come up with anything but I know some gas engine guys will know how to approach this. Need the garage back from a too long BMW on Vette project. Am moving to basement but the basement is two feet lower than the outside. There could be a little gasoline and worried about explosion potential. To be safe, how do I vent this area? There will be no ignition source but lighting. What I'm concerned about is going down there to work, flipping the light on and...
Also, there is a bed down there - I suppose a scenario could arise where someone in the doghouse could sleep there. What's the way to do this?

[rasorinc]

To really vent you have to use fans. Install a sniffer control to do continual montering and read it before using electricity. 2 large fans either pushing or sucking to an evacuation point.
Or one pulling air out with the other pulling air in--just like an engine room. Or light a match to check for leaks or fumes before turing on power.
Chect out some in-line fans to see if powerful enough to do the job. You did not say how big the room was. Do you have 5/8" sheetrock on the ceiling? http://www.industrialfansdirect.com/...Fcns7QodZG2nyw

[Squidly-Diddly]

I've personally witnessed a steel hammer striking concrete and lighting gas fumes from nearby recently fueled chain saw.

I believe iron dust(like from sanding) can spark fires just from heat from 'rusting' in certain conditions.

Any non-marinized electric motor sparks AT LOT but I've never experimented with that and gas fumes.

Good(and bad)news is the gas fumes really hug the ground, as seen if using a splash of gasoline from chainsaw to start a campfire.

I'd mount a fan high up and pointing down to disperse any fumes.

A roof mounted vent with tube down to the floor would work but only if there is enough household heat or outside wind to suck air.

I'd be thinking more "disperse" than "vent". The fumes from the chainsaw lit-off on an outside slab with all the 'ventilation' in the world. You could have two windows wide open with fans going and it might not help if the air by the ground is relatively calm (like under the boat, car or lumber pile).

I've seen a trial of fumes from a campfire snake out over 20' hugging the ground and lit-off when the fire is lit, and that is certainly with lots of 'ventilation'.

[viking north]

Alaska is about to compete with Florida's launches Agree with Rasorinc a sniffer is a must to control ventalation and a dual powered alarm in case the power fails and someone (not mentioning any names here) is in the doghouse. Mark a small house AIR exchanger should do the trick, remember intakes at or near ceiling heights, gas fumes rise I THINK unlike propane.(CHECK ON THIS) Control the air exchanger with the sniffer not a humidistat. The air exchanger has an outside air intake and exaust, also moves a high volume of air. Geo.

[viking north]

Squidly- could be wrong here but I think that gasoline fumes rise however Mark in a small space it probably makes little difference --The house air exchanger has a large intake and is designed to be broken down into several intake feeds so why not place two or more low an two or more high. Also might be a good idea to think about where to mount the exchanger unit. Maybe someone with a fume extraction background can do that recommendation.IMPORTANT-if you spill gasoline don't vacuum it up with a wet vac, friend of mine did that thinking it was water in a fuel bunker--got killed stone dead. ( sleep down there ? not me , head for the comfort of the Husky Pad.)----Geo.

[rasorinc]

gas fume detectors--I've seen them from about $50.00 up to $200.00.
http://www.westmarine.com/1/1/13698-...-detector.html If your just talking about stored gasoline then double box it and use an intake fan and an exhaust fan. http://www.wholesalemarine.com/p/MTI...+Detector.html

[cthippo]

Originally Posted by viking north

gas fumes rise I THINK unlike propane.(CHECK ON THIS) Control the air exchanger with the sniffer not a humidistat.

Gasoline and propane fumes are both heavier than air and will sink. Natural gas, on the other hand, is lighter than air and rises. Put your gas detector at floor level.

I wasn't totally clear on what you plan to do in this space, but I would also look at Carbon monoxide, which will kill you faster than combustible fumes. A couple years back it got so cold that the cold storage place shut the doors because it was colder outside than in the freezers. CO from the forklifts sent 6 people to the hyperbaric chamber at Virginia Mason Hospital in Seattle with CO poisoning. Nasty stuff.

[viking north]

Thanks, cthippo wasn't sure on that I always get them mixed up, Natural gas --knew one was lighter.--Geo.

[cthippo]

Natural gas is mostly methane (CH4) whereas Liquid Petroleum Gas (LPG) is mostly propane (C3H8) and butane (C4H10).

[messabout]

I will reinforce the above statement that gasoline fumes are heavier than air and they DO NOT rise. That the fumes rise is a popular misconception that can, and does, get some very nice people in a batch of flaming trouble.

For the OP. Why will you have gasoline fumes in the basement? Will you be working on the fuel tank, testing fuel pumps, or fiddling with the fuel log while the engine is running? I do think that you'd ought to remain vigilant about this potential problem. However, the likelihood of generating fuel fumes is small unless there are leaks somewhere in the system or the basement is very hot. If the basement contains a furnace, or an AC unit, then the need for an evacuation system is a no brainer. You must install it.

If you install an evacuation system, then let the intake vent, inside the room be at a floor level. That'll be where the problem is, if it is there at all. Also you will need to use an explosion proof evac system. EP motors cost more but they are worth the extra cost if only for peace of mind.

And one more thing dear reader. If you have an inboard engine in your boat, dont even think of starting it before you blow the bilge.

[CDK]

The combustible gasoline/air mixture has a breathtaking smell and stings the eyes. If you willingly make sparks or use open fire under these circumstances you have a death wish. A faint gasoline smell is nothing to worry about.

Carbon monoxide is much more treacherous because it has no smell at all. I'd install both a sniffer and a big fan in a basement; even a stove can be dangerous.

That was the plan, I was simply looking for some specifics. Thanks all.