3000W Chinese Gensets Info.

joelabq wrote:

Katdaddy wrote:
Ok folks I need opinions from those of you who are much smarter than me. I have a wild notion for an enclosure to help with the noise. I was wondering if an enclosure with a chimney built into the top would be feasible? I hit on this while tending a fire in my fireplace at home. If I open a window while the fireplace is lit a considerable breeze comes through the open window. So my idea/question is; if a chimney is built into top of enclosure and a gap is left at the bottom will the chimney draw sufficient, if any air through the gap at the bottom to help it stay cool? Also for consideration is whether or not the gap will allow too much sound to escape busting the whole idea? I look forward to hearing your thoughts on this.

I think there is way to much heat load for convection to work while maintaining sound abatement. The enclosure I'm working on I've noticed a large increase in sound if I increase the gap at the bottom. I get around 3dbA from just 3/4" rise on either side.

With a ~ 5000 CFM 12v fan running, I can keep the temp probe near the muffler (touching the Gen head) around 170F (with no gap at the bottom of the box. With a 3/4" gap, I keep it around 134F. With no fan and a gap, I hit 196F at the same spot, and if I take away the gap I noticed no real difference in temperature. I tested all these yesterday eve @ around 50F last night, so I am sure these will climb some in higher ambient. Now, Mind you this is with a baffed vent for th fan on top, which does keep "line of sight" out of the picture. I don't believe I could obtain as great of noise control without that, and I think a "chimney" would let a ton of noise out - only way I could see would be a tall/large/bulkly chimney that would make for difficulty in transport. With that said, if it can be done, I would love to see it.

On a side note:

So far with a temp probe on the cylinder head, normal temps around around 120-125F no load. With the enclosure/fan/and circulation using a gap at the bottom, 137F. I honestly thing heat increase in the enclosure isn't going to effect the engine all that much, even without a gap and no fan running the temps seems to peak out around 160F at the head. I am more concerned about the generator/wiring. I am really thinking of moving the muffler out of the box. Likewise, I think the Gap at the bottom idea lacks alot of the sound control for my taste. I need to figure out a better solution.

I think you're on the right track with your thoughts of moving the muffler outside the box.
Also, in all the research I've done on the internet on noise abatement the one thing I keep seeing over and over is "Sound doesn't like to travel around corners but air does."
Good luck,
JerryK