The high winds that blew from Tuesday morning until the wee hours this morning induced me to take the 3,000 W generator in for servicing. It’s a Honda, so it’s not especially loud. It’s quiet enough inside of the house with the French doors closed, but we do spend time on the deck, and I worry about disturbing the neighbours. (In reality, it’s probably not so loud as to disturb them.) Can I build something to reduce the noise?
I don’t want to set it out in the rain, so it will be used on the deck. The roofed area is 17 feet wide and 24 feet long, and the deck is made up of 2x6s spaced about a quarter to a half inch apart. I built a dolly out of scrap 2x6s, and the generator is secured to it. I could easily build a box to cover it, but it needs air to run, the exhaust needs to get out, and I don’t want it to overheat. Other than laying the chaise longue on its side to baffle two sides, and arranging an ottoman or two to accomplish the same, do you have any ideas about how I can reduce the noise?
I’ve seen vendors at festivals use a food-safe plastic barrel. They cut out the bottom and then cut it down to about half the usual height. It isn’t silent but does direct a lot of the noise up instead of out.
Put a few heavy blankets, foam sheets or carpeting around and under the platform of the generator. Don’t use anything hard as that will just deflect the sound and possibly make it louder because of reflected harmonics of the original noise.
Here’s how I soundproofed ours. Although it was for camping, some of the methods might be useful.
I put it in an aluminum truck box. I sawed out a square opening on each end and installed a vent. In the first pic, you can see the temperature controlled fan attached to the left side vent. The aluminum tube mounted to the vent fan is to diffuse and carry the exhaust away. It joined a homemade plenum in the rear to ensure no hot spots from the generator’s exhaust output. I ordered a roll of high temperature sound deadening material from B-Quiet company and glued it around the sides and top of the box. You can see one sheet of it here a little better. I placed the generator on a rubber mat (visible in the photos) to stop vibrations from transferring to the truck bed also. Although necessary in this use because a truck bed can work like a speaker, it might not be necessary when mounting to a deck.
We used this repeatedly, and even in the “no generator” sections of Yellowstone without being called out for it. It wasn’t silent, but only generated a low hum. When measured with a decibel meter, it was about the same as our dishwasher.
I’m extremely impressed by your efforts, pullin. I assume that truck box is mounted permanently on the back of the truck you use to tow your camper with? My only contribution to this thread is that *I *already own a quieter generator. Specifically, a 2012 Toyota Prius. With a large inverter mounted either on the 12 volt battery or there are special high voltage inverters you can buy (although they are very expensive) that mount directly on the battery. Anyways when the car’s engine is running it’s quiet and it’s a generator that is fairly fuel efficient and has an output of about 10 kilowatts.
isolate the feet of the generator so it doesn’t transmit low frequencies to the deck. Any variation of the barrel idea with insulation. make sure it can draw fresh air in and expel exhaust unimpeded so it doesn’t overheat.
This is exciting, would you explain? My assumption is your Prius is a hybrid, but I don’t understand/know the battery voltages involved, nor what you mean by “high voltage” inverters (as opposed to low voltage?). Also, is your alternator/charging system capable of maintaining a 10kw load indefinitely? Any idea of specific gallons per hour under load your Prius consumes while using it as a generator? Any info would be appreciated.
Thank you! And yes, it was mounted permanently in the truck bed. I used the truckbox method both for quietness, and to hide the presence of a generator (at launch ramps, or other places while camping – didn’t like to leave it at camper).
I’m very interested in your inverter additions to your Prius. We have a Camry hybrid, and I’ve been wondering if there’s a way to capture any of it’s capability for generation. I have a couple of large portable* generators for keeping the house comfortable, but I haven’t soundproofed them at all. The Camry would be considerably quieter.
*“Portable” means they have wheels. Too heavy for me to wrestle around more than a few feet, and I have to lift them into the truck bed using either a chain hoist, or engine hoist.
The old standard for the Army was to surround them with sandbags or a dirt berm. It absorbed or reflected the sound moving generally horizontally while still allowing good airflow. Without digging holes in your yard, there’s options like bags of kitty litter or potting soil. Litter is probably cheaper. With some bracing on the perimeter of your cart, you can probably stand the bags up on side or end to form a barrier and minimize the number you need.
Some years ago, I built a simple wooden box (four hinged panels and open at top and bottom) out of plywood. I stapled heat resistant insulation (foil and fiberglass) to the inside surfaces. I used door hinges because they allowed me to remove the hinge pins and collapse the box into two pieces that fold flat. I allowed plenty of space on each side of the generator for air movement. I scalloped the bottom edges slightly to allow air to enter at the bottom of the box.
I then placed the generator itself on a rubber kitchen mat I got at a restaurant supply store.
This made a huge difference in the sound level, as described by others above. The sound went straight up. The whole assembly cost me about $45 to make.
I built a rolling generator shed for mine. Insulated for noise, adapted a car muffler for the exhaust. Hinged lid to make fueling easy. I can barely hear it run outside, I hear nothing in the house. Haven’t had to run the generator for a power outage since I built it.
I’ve had to run it for power outages. I think there have been three or four since I got here. I was in L.A. and a friend was staying in my house when there was a massive snow storm in… 2006? 2007? I bought the generator over the phone and he went and picked it up. (Only went off the road once!) He and his dog were able to keep warm (propane furnace, but electric fan) until the power came back. On the few occasions the power has gone out while I’ve been living here, it was only out for a couple of hours. The cable worked, so the Internet worked, so I could telecommute and have the TV on. The last time it went out, it was out for three days. No cable, no Internet. But the generator ran the TV, the DVD player (Mrs. L.A. had bought me the The Man From U.N.C.L.E. boxed set for Christmas ), a couple of lights, and, most importantly, the coffee-maker. (It’s nice having a coffee-maker, even though I have a few non-electric ways of making it.)
The last time the generator was used was in Summer, 2016. We were having the deck and deck roof built, and the guys were using it to power their tools.
), a couple of lights, and, most importantly, the coffee-maker. (It’s nice having a coffee-maker, even though I have a few non-electric ways of making it.)