I have a portable generator 6kVA (9kVA peak) with a Briggs & Stratton little engine that is quite reliable and sometimes runs for 24 hours without a hitch.  However, it's very noisy.

I like to keep a low profile and even being able to power virtually all house (just turn off baseboard heaters, washer and drier machines and electric oven), I just turn on the essential lights to make minimum "advertisement" that I have one.

The noise, however, is high and I'd like to reduce it to a minimum, preferably to the level of those Honda Eco levels.


Any ideas?  

I would not want my cars running a 24 hours cycle inside the garage.  Danger of fumes and even damage to the engines running without proper ventilation.  The genny, if push comes to shove, is disposable and cheaper to replace than the cars.

Refrigerator, microwave, furnace (it's oil and only needs power for the blower), lights...  And Internet.  I have fiber and that stuff keeps working through power outages if I can power my router and computers.  

Utility here wants me to hook up at least three appliances in my house for them to connect it to the pipe that passes right in front, there's a minimum consumption charge either.  Nope, thanks.   Plus several turn on fees.  

A quick google or YouTube search on portable generator enclosure(s) turns up hours of reading.

https://www.youtube.com/results?search_query=portable+generator+enclosure+

1) replace the muffler with something MUCH bigger
2) extend the exhaust pipe several feet
3) enclose entire genny in box with sound insulation.

This will be the most effective. But I highly recommend venting the top of the container and adding a fan to draw air through the container.

Many scooter mufflers will work wonders however as mentioned you'll have to extend the pipe a bit to add to the effect.

Running a car for power is an incredible waste of fuel.  It'll work in a pinch but it's pointless for that to be THE plan.  Car batteries are also not made to be deep discharged....do that a number of times and you're going to be buying a new car battery....regardless of how old it is.  

I would rather run my cheap, low fuel consumption generator than my expensive cars to power my house.  

An extra muffler will probably help but you'll find that the actual generator itself is what is generating a large amount of the noise.  If you want to get to Honda inverter levels of noise, you're going to have to install a sound enclosure.

http://www.alpharubicon.com/altenergy/gensetquiet.htm

I have looked into this a lot over the past several months.

The single most effective way to reduce noise is to put the generator in a box. The crazy thing is that it doesn't even have to be a special sound dampening box, a simple wooden box will do wonders.

Add a better muffler, extend the exhaust out a bit, add acoustic tiles/foam etc to improve.

"Silencer box" is what you want to search on YouTube.

There's a bit more to running an inverter from a vehicle...short version, it's not worth it and will smoke things out in short order.

If you have a "purpose built" rig, like the mil add-on inverters used in their 24 volt applications, you can get the job done, but everything is already beefy. The alternator can take the duty cycle, the batteries are diesel rated (greater capacity) and 24 volts (lower current), the lead to the inverter are the size of your fingers and with all that, they run an 1800/2000 watt 120v output. No provisions for 220v (furnace, well pump, etc). You will burn around 1/2 gal an hour at idle and the "car" alternator will not put out anywhere near the rated amperage at idle speeds.

Can you do it? Yes

Can you put together a cheap turd system, with a cheap switching type inverter and some jumper cables? Yes...Not being a snob, it's junk and will smoke more than it helps.

Will it cost 3 or 4 times the cost of a gas genny to build a reliable system, yes.

The shortest distance between two point is to get a gas generator and learn to repair the basics (needle, float, etc)

As far as "low profile", you don't need 5000 watts if you're in conservation mode. Get a suitcase inverter genny for quite time and a cheap 5500-6500W for the big loads. Forget KVA for home descriptions. You are "usually" limited by the nema 30 amp connector on your average home genny...that unit of measure has no bearing on the mission.

Build up an extension pipe and route it out of the genny hut to get the heat out of there. It depends on how committed you are to this project. As stated, silence the mechanical noise with walls/insulation and the exhaust with an auto muffler contained and vented into a larger container (barrel w vent).

Kind of like this guy?
http://www.invertersrus.com/prius-power-inverter.html

We had a pretty extensive thread about quieting generators.  The pros and cons and experiments with multiple mufflers, bigger mufflers etc.  Also housings to attenuate sound.  Might need to search the archives.

1. car running and doors locked, eh?  there is no chance then that someone will break the side window and steal your entire car?

2. larger fuel tank, true.  and you'll need it since you are making something on the order of 30HP at idle to power a few things in the house.

was this a serious answer?

ar-jedi

ar-jedi

if you live in a condo/townhouse, yes.

if you live where there is actual space between houses, no.

ar-jedi  <-- has EU2000i.  ran it for 12 days straight once.  not stolen.  still have it.   (clicky linky)

Thanks!  I was imagining this topic was already covered but forgot to browse the archives.  Did not find anything in the "live" threads.

The ideas are nice.  My generator does not seem to have a big muzzler on the exhaust port, hence I was thinking about working that part first.  

The Honda genies really impress me on how quiet they are.

I did this trick 5 years ago. I used a muffler and tail pipe off my junk truck before it went to the junkyard. welded a 2 1/4 pipe on the genny muffler and all i needed to buy was a 3 foot piece of flex and a couple clamps. It's very quite.



 

You're asking your 6k watt generator with an engine roughly 342cc in size, to be as quiet as a 2000k watt 98cc honda engine?
Yes, the Honda's are quiet, but only when a small load is applied to them.
Your Briggs and Stratton genny has a much bigger engine and has to run at a static higher rpm to maintain output (usually 3600 rpm) regardless of load.

You can build a box or doghouse around your generator, but in the long run if you want to reduce your noise and run just the basics you listed off in your first post, maybe a smaller generator is in order?

The expensive solution is to get a few solar generators. Completely silent and doesn't need fuel.

But very expensive.

Dig a 2 foot hole and run garden hose from exhaust into the hole. Works very well. The hose will harden after awhile but all you need to do is cut off the few hardened inches and reinsert. I used this method with noisy 1.5KW and 4.2KW generators in the Army.

what a ripoff......

a box with a 50ah battery and a 1500w inverter for a mere $2k    O hell no....

Thanks!  I'll get exhaust extension.  Most of the noise appears to come from the exhaust, which seems to be almost non-existent.

I can build a wooden box and put it under the deck where it will be well sheltered from the elements and "temptations".

A bit pricey but clean package. I am building a portable (towable) solar gen right now with 1680ah and a 4k trace inverter. Has 1k worth of panels and 1,5k on a wind turbine. Not counting my labor (probably 200hrs to build) I have almost $10k in the project. Solar/wind is not cheap upfront but will pay you back quickly and batts are about the only cost later, maintenance will improve the life.

I think sand bags would be the most effective. build a wall around it and direct the exhaust up.

How could they steal it........? I mean, it has an extension cord plugged into it that tethers it securely to the house.........

That's what I would do.  Find a very large automotive muffler with the minimum inner diameter inlet pipe, and angle the exhaust out of the muffler up at 90*.  Install the genny in an insulated enclosure and that will dampen all of the engine noise.

Bigger muffler would be the easiest thing, after that I would say build a enclosure with hush mat or something padding the inside. Problem there's going to be heat, could probably rig up some ducted fans with baffling to vent the enclosure.