I have a 3KW Honda generator (the eu300is, really good.) It sits in my garage under its cover with a trickle charger feeding it current. On the wall I have a rolled-up heavy gauge electric cable long enough to reach it when it is rolled outside, which feeds the current back to a six-breaker transfer switch installed next to my 200A house panel.

I also keep (3) 5gl red metal jerricans full of gas in the garage, spiked with Stabil. Yes, I know that's a terrible place to store the gas. I run the generator for a few minutes every couple of months.

We recently had a stick-built 12'x12'x7' shed constructed in the corner of our back yard. Two windows, concrete pad floor and both 110V and 220V service (in case I want to add a compressor later.) The shed is not insulated, but it does have a shingled slant roof with a ridge vent. We're using it for storage primarily, camping stuff, lawnmower, power tools, etc.

Naturally I'm thinking about moving the generator to the shed and getting it out of the garage.

Questions: 1. If I open the windows, what's the danger of CO buildup running the generator in the shed during power outages, if no-one is in there while it's running? (Except to run it and refuel/turn it on and off). I like the idea of having it in a protected space during a storm. Right now, it would sit in front of my garage, in the elements, when needed. 2. Is it better to store the fuel in the shed? If not there, or in the garage, then where?

1) Is it possible to duct the exhaust to the outside?

I don't think this unit was designed with external exhaust ducting in mind. I was thinking since the shed is at least 30' from the house, encloses a fairly large volume, and wouldn't be occupied while the genset is running, that it would be safe enough.

I don't think that the Honda EU3k gennys are designed to easily duct the exhaust outside either. If it was mine i would run it in the shed as long as it was well away from the house. Open the windows and if there is not much breeze put a fan in the window. It might be possible to add a few vents at or near the bottom of the shed might help also.

Don't like having gas anywhere near the house so i would keep that in the shed also. If you install an air compressor out there make sure that you are using higher quality gas cans. Some of the cheaper ones i have seen always reek of gasoline. I would not want to have a compressor sucking up gasoline fumes and packing it into a tank full of air, unless you are Blast.

Garages just use a flexible hose something like dryer vent to route exhaust gases outside in case they have to run an engine inside the shop space.

How hard would it be to partition a space for the genset off and ventilate that area. Basically a generator room.

Most of our industrial gensets (caterpillar units) at mines and construction camps were in very simple sheds that were little more than a roof and only protected against rain and snow. We didn't even sheath the walls all the way to the ground so the shed was well ventilated.
We expected diesel units to start automatically at -40 so they did have block heaters and fuel preheaters on them.
(I doubt if you will need that)

Maybe you could add some louver vents to your shed in the generator's room. Both low and high to get rid of heavy and light gases.

Fuel storage is always a problem. If you can't leave it out in a little dog house of its own then in the outside shed where you intend to put the genset is the next best thing.
The farther from where you sleep the better, (right?)

Even if the genny isn't designed for it, you can use the equivalent of a welders exhaust; ducting placed near the exhaust and a fan to draw the fumes out and exhaust them outside. Link it to the supplied transfer block so it only runs when the genny does, potentially automatically as well. Remember, there is also soot, water vapor, etc in the exhaust. You really don't want these to build up in the shed either, especially if you are storing other things like camping gear.

Regards,
Bill

Good idea Bill, didn't even think about a welders exhaust. The exhaust vent on the rear of the EU3k is wide vent across the back of the generator that also allows for all of the engine heat to be vented out of the box. Should be easy to fabricate from parts from your local building supply.

I would install an exhaust fan to pull fumes out and at the same time keep a window or two open when the generator is operating. That should eliminate any danger from carbon monoxide build up.

Storing the gasoline in your garage might violate terms of your homeowners' insurance policy and thereby void your insurance in the event of a fire. Storing the gasoline in the shed should not be a problem as long as it is not near the generator. You might check with your insurance company to be sure there are no problems with storing the gas in an outlying building. Also a good fire extinguisher rated to handle gasoline fires and mounted near the door would be a good addition.

Good reminder about an extinguisher.

Does a generator put out a huge amount of soot that it would befoul everything else in the shed?

As the shed is 12'x12', I can store the generator in one corner and the gas in another. But it does sound like it's a better option to relocate the generator to the shed from the garage. I'll need to get an electrician in to re-jigger the transfer switch for the updated setup. I wouldn't want to partition the generator off though -- the room's not that big.

I have to remember that this is only when the neighborhood power is out and I won't be doing anything else in the shed except checking on the generator. If it's not raining I can even stick the generator in the doorway with the exhaust side facing out. The important part is that it's inside my backyard fence, so harder to steal.

Thanks for the advice.

You made an excellent generator choice. I really like the one I purchased.

Regarding theft, I would also chain the generator to a long U-bolt sunk into concrete, or something equally immovable.

A little more deterrence is a good thing.

On the same note of shed security, my friend noticed that things were going missing from his barn.

He decided to install an Infrared game trail camera inside the barn to figure out what was going on.

A few weekends later, the camera took several very clear pictures of his next door neighbor walking out of his barn with some tools.