Honda 30IS — “indoors”? Exhaust extension?

[Messier11]

I’ve built a little concrete shed/bunker for our old generator a few years ago. Even with a fairly effective pipe fan (183 m3/h) sucking air from high inside the shed and an air intake in the door (ie should get circulation) the generator didn’t quite get enough air. But it has worked perfectly since I connected an exhaust extension to it.

I don’t have any good pictures, but here is one from afar and one taken winter time:







Anyway, the old generator has given up and I got a chance to get a Honda 30IS for a good price.

Does anyone have any experience on extending the exhaust on those things? They ‘recommend’ against it in the manual (a picture of it crossed over in red…), but it does seem like one of those things that could damage things if not done properly but should work most of the time. But is the exhaust even accessible? What type of connection would be required? And how sensitive is an engine to too little oxgene?

Any thoughts are appreciated!!

 

[Supervstech]

One issue might be poor exhaust scavenging from the long exhaust. Could result in overheating, and poor power output. With an air cooled engine, heat tolerance may cause rapid failure.

 

[Messier11]

One issue might be poor exhaust scavenging from the long exhaust. Could result in overheating, and poor power output. With an air cooled engine, heat tolerance may cause rapid failure.

Yeah exactly, and when I googled some, I saw some discussion on the topic. Apparently the ‘resistance’ in an extension with a 90 degree curve is of course a little higher, but it was very very marginal which makes sense (in terms of %). Like how hard is it to blow air right out in the open vs through a pipe that is like a 2 feet long and has a 90 degree turn. In the example I saw the difference was like 0.2% or something. With that said, I have no idea how sensitive these things are.

I am just surprised that I barely can’t find any examples of people extending the exhaust on smaller generators. A proper back-up system is of course built for a longer exhaust. But people use these smaller generators as back-up power too, right? Do everyone really start them and put them outdoors?

 

[ElectricIslander]

Way too small an exhaust pipe !!!

Instead of routing exhaust in a little pipe, for my Honda 3000Eu and 2200Eu generators I built custom aluminum adaptors to transition the cooling air flow with the contained exhaust into a square heating duct to that adapts the air outlet to a 6" pipe. That way all of the hot air and exhaust go up and out of the generator enclosure in a 6" pipe. For inflow into the heavily sound insulated 2200Eu box, I have two 3" holes in the floor. The generator never gets warm in the box and I route the outflow up into an insulated sound absorbing chimney via 6 foot long 6" aluminum flex tube (like dryer duct). The gentle bend in the duct has very little air resistance. You can barely hear the generator running when the box is closed. The box has walls 2.5" of Roxul Dense Board (compressed rockwool) and a removable 3" neoprene foam lid, with a floor made of stable rubber sheet matting, and swinging rubber door made from a layer of 3/4" rubber stable matting and two layers of hanging 1/8" EDM rubber.

Have 4400+hrs on the H2200Eu now, it gets fresh Mobil Synthetic every 100 hrs by hour meter and add Seafoam every few fill-ups (to avoid coking up due to primarily low rpm operation). Works perfectly, starts first pull, barely burns any gas when on eco throttle - Have 5 gal outboard tank plumbed into fuel cap. Lasts for about 4-5 days between fill-ups and runs 16 hrs a day since we don't have any meaningful amount of solar yet.

 

[Messier11]

Thanks!!!

So how would you do it in my bunker? The only accessible area is the front, basically a door and the frame.

Do you have a outboard tank connected to the fuel tank of the generator?

 

[Checkthisout]

Thanks!!!

So how would you do it in my bunker? The only accessible area is the front, basically a door and the frame.

Do you have a outboard tank connected to the fuel tank of the generator?

Which Honda are you getting?

 

[Messier11]

Which Honda are you getting?

30IS

 

[Checkthisout]

30IS

Ah OK, you're in a foreign country. (Not U.S.) I didn't recognize the model.

That's the equivalent of the EU3000is here in the states.

At any rate, all the exhaust and cooling air comes out of a single vent on the side of the machine. Just direct this air into a large duct, say 2 feet x 2 feet. It will naturally draft up and out of your bunker.

 

[ElectricIslander]

Thanks!!!

So how would you do it in my bunker? The only accessible area is the front, basically a door and the frame.

Do you have a outboard tank connected to the fuel tank of the generator?

Use a small diameter hammer drill and drill a 6" ring of holes in the concrete of the roof of your bunker and mortar in a 6" stove pipe, run it up 6 feet to create draft and put a cap on it to keep snow off it. Adapt the cooling/exhaust grille to the 6" stove pipe with sheet metal and flex pipe.

Yes, the Honda 2200's have an onboard fuel pump that will suck fuel into the integral tank if you have a cap with fuel fitting.

Don't know if that works with the Honda 3000's though - don't think so. If not, you would have to connect the external tank direct to the carburetor and have gravity feed from an external tank at a similar height range to the integral tank (so as to not overpressure the carb float valve).

Alternately, convert to propane!

 

[SamDeleted]

Honda Genos are easy to convert to LPG (propane) , lots of advice online if you are interested

 

[ElectricIslander]

Some details of our "temporary" open sided generator shed with Honda Eu2200 enclosed for sound reduction and protection from the elements. Hopefully this info will help others dealing with the same issues.

Both the Eu2200 and the Eu3000 have home fabricated aluminum "snouts" on the combined cooling/exhaust air outlet grilles. You can buy these online pre-made by others in molded plastic if you like.

The sound enclosure uses compressed rockwool inside, surrounded and underlain by 3/4" rubber stable matting all in a corner of the 1/2" plywood shed. The generator sits on a cushion of rockwool covered by plywood, this serves to isolate generator vibration from the floor and prevents the plywood floor from acting as a drum. If I was doing it again I'd line the rockwool interior of the enclosure with 1/8" EDPM pond liner rubber sheeting to contain any potential rockwool dust. I'm just careful to not disturb the rockwool and clean the air filter. But our generator is not the worse for wear as it has 4500 hours and runs perfectly. This enclosure is extraordinarily effective at reducing the generator noise.

Note the four essential items for generator maintenance when you have a permanently mounted generator:

1) Hour Meter (you can get these for C$ 45 from Honda Dealers. Using synthetic oil, even changes at 100 hr oil still look pretty clean.
2) Graduated funnel with cover, flow valve and hose cap: Makes filling to exact amount super easy and dripless.
3) Oil pump, just put hose in crankcase and give it a few strokes and old oil is removed.
4) Additives to prevent carbon accumulation on Honda inverter generator valves. When run long hrs at low rpm it's easy to carbon up the valves. Adding something like Seafoam, fuel injector cleaner, Techron etc. helps keep carbon off valves and generator out of repair shop. Running ethanol free marine gas costs a little more but highly worthwhile to prevent carb problems.

 

[Supervstech]

Simply amazing ideas here.

Perhaps instead of rock wool, or in addition to it, some “eggcrate” style foam on top?

 

[ElectricIslander]

The two sheets of soft expanded neoprene foam just sitting loose on top really cut the noise well and are easy to deal with as a lid. I lucked out and found them in a second hand marine store, no idea where to buy more of that stuff, it's a super effective sound absorber material. I've seen the same stuff with a central layer of lead sheet which would be an even better sound barrier - that stuff is used on commercial boat engine rooms.

 

[Bluedog225]

Genny inside sounds like a good way to die. Too many ways the intake/exhaust can go wrong. No warning. Just night night.

 

[ElectricIslander]

Genny inside sounds like a good way to die. Too many ways the intake/exhaust can go wrong. No warning. Just night night.

Note that it is a 4 foot deep open sided shelter covering an enclosure - not inside!!! And it's on top of a cliff next to the sea with a constant sea breeze too!

 

[SamDeleted]

Running ethanol free marine gas costs a little more but highly worthwhile to prevent carb problems.

Have you considered running propane ?

 

[ElectricIslander]

Yes, still have a propane line run into shed from previous Ryobi 900W Inverter propane generator installation that we ran till it leaked oil from every pore (multiple teardowns and re-sealings ...). Finally ended up with the camshaft gear disintegrating. Was nice while it lasted. Kept the crankcase and nice little integral permanent magnet alternator for a potential mini-hydro project but will have to rewire the windings for lower rpm.

Our neighbours have had mixed results with Honda propane conversions, one is flawless, other with exact same generator and same conversion kit has had no end of problems.

 

[Checkthisout]

Yes, still have a propane line run into shed from previous Ryobi 900W Inverter propane generator installation that we ran till it leaked oil from every pore (multiple teardowns and re-sealings ...). Finally ended up with the camshaft gear disintegrating. Was nice while it lasted. Kept the crankcase and nice little integral permanent magnet alternator for a potential mini-hydro project but will have to rewire the windings for lower rpm.

Our neighbours have had mixed results with Honda propane conversions, one is flawless, other with exact same generator and same conversion kit has had no end of problems.

If you're using it all the time, gas is fine.

Propane is better but sometimes costs more, reduces power output and makes you reliant on aftermarket conversion parts that don't always function reliably.

 

[wme]

More bucks, but it works. https://www.zombiebox.com/

 

[Bluedog225]

Emp? Skeptical.