Suggestions for a smallish, ultra-quiet LPG generator?

AceNZ

I live in a suburban residential neighborhood, with noise restrictions for generators and similar equipment: 55 dBA during the day, and 45 dBA at night.

I have a hybrid solar setup, and normally have grid access, but I'm thinking about getting a generator as extra insurance in case the grid goes down for an extended period. The generator would be configured to only run during the day to charge the batteries.

Since it would mainly be needed for emergencies, I wouldn't use much fuel most of the time, but I would also like to be able to store a fair amount. That probably rules out gasoline. Diesel might possible with some effort, but the city generally requires fuel storage in residential areas to be underground, which would add to costs -- plus, it's still not maintenance-free.

Natural gas isn't available here -- so that leaves LPG. We also use LPG already for other reasons (stove and BBQ).

So, I'm looking for a very quiet, LPG-powered unit, probably in the 2 to 10 kVA range. Any suggestions?

Cariboocoot

Re: Suggestions for a smallish, ultra-quiet LPG generator?

Buy a Honda inverter-gen and get it converted to LPG.

mtdoc

Re: Suggestions for a smallish, ultra-quiet LPG generator?

The quietest you'll likely find is a converted Honda eu3000i - at 49dB. Other Honda and Yamaha inverter gens are only slightly louder. Have a look at Central Maine Diesel for options.

AceNZ

Re: Suggestions for a smallish, ultra-quiet LPG generator?

mtdoc wrote: »

The quietest you'll likely find is a converted Honda eu3000i - at 49dB. Other Honda and Yamaha inverter gens are only slightly louder. Have a look at Central Maine Diesel for options.

I think the equivalent 240V version is the Honda EU30is. They're available locally, but I'm not sure about LPG conversions -- do you know if those are straightforward to do yourself? Are conversion kits available?

The conversions from Central Maine Diesel look great. Too bad they aren't closer.

mtdoc

Re: Suggestions for a smallish, ultra-quiet LPG generator?

Oh New Zealand.... Yeah CMD is a bit far.

I own a trifuel eu2000i from CMD and it works great. I have not done a conversion myself but many have.

Have a look around the Yahoo Honda eu2000 group

Lots of good info there.

northerner

Re: Suggestions for a smallish, ultra-quiet LPG generator?

I recently purchased locally a Yamaha EF3000 and am extremely happy with it. It's even quieter than the Honda EU2000 I was running previously and starts and runs better in cold weather.

I also purchased a conversion kit from uscarb.com which is more of an adaptation than a conversion and consists of a snorkel. It's effectively a hose that feeds the gas through a slit in a thick gasket, and I find it works very well. It is also relatively inexpensive and doesn't involve modifying a carburetor. You can run propane or natural gas, and still have the option to run on gasoline if need be. Definitely recommended!

AceNZ

Re: Suggestions for a smallish, ultra-quiet LPG generator?

northerner wrote: »

I recently purchased locally a Yamaha EF3000 and am extremely happy with it. It's even quieter than the Honda EU2000 I was running previously and starts and runs better in cold weather.

I also purchased a conversion kit from uscarb.com which is more of an adaptation than a conversion and consists of a snorkel. It's effectively a hose that feeds the gas through a slit in a thick gasket, and I find it works very well. It is also relatively inexpensive and doesn't involve modifying a carburetor. You can run propane or natural gas, and still have the option to run on gasoline if need be. Definitely recommended!

That uscarb.com website is a disaster, but their conversion kit looks pretty good.

The Yamaha EF3000ISE is available locally. Not cheap, but then neither are the Hondas. The size and noise specs look good, though.

Could be a winning combo.

The main thing I'm uncertain about is the connection from the regular to an LPG tank. I vaguely recall some issue with English vs. metric threads when I went to buy a replacement hose for my BBQ some time ago.

BB.

Re: Suggestions for a smallish, ultra-quiet LPG generator?

You also need to worry about tank size, outside air temperatures, and engine Horse Power... If you pull fuel vapor too rapidly from the tank the liquid propane temperature falls, and so does the tank pressure. Cold enough, fast enough fuel draw, and the engine will stop running.

Even for a smaller genset, you may need a 50-100 gallon tank to run for many hours without freezing the tank (depending on how cold it gets, size of genset+loads, etc.):

http://www.engineeringradio.us/blog/2010/10/care-and-feeding-of-propane-fueled-generators/

-Bill

AceNZ

Re: Suggestions for a smallish, ultra-quiet LPG generator?

BB. wrote: »

You also need to worry about tank size, outside air temperatures, and engine Horse Power... If you pull fuel vapor too rapidly from the tank the liquid propane temperature falls, and so does the tank pressure. Cold enough, fast enough fuel draw, and the engine will stop running.

Even for a smaller genset, you may need a 50-100 gallon tank to run for many hours without freezing the tank (depending on how cold it gets, size of genset+loads, etc.):

http://www.engineeringradio.us/blog/2010/10/care-and-feeding-of-propane-fueled-generators/

-Bill

Interesting info; thanks.

If the batteries are drawn to 40% DOD and not recharged at all by solar, the most the generator should need to deliver is about 20 kWh per day. For the Yamaha EF3000ISE, which is rated at 2.8 kVA continuous, that would be around eight hours of run time.

That's 5.5 HP, or 55,000 BTU/hr. I'm pretty sure my BBQ pulls more than that. Plus, our annual low temp is only around 1 deg C -- so should be OK.

Blackcherry04

Re: Suggestions for a smallish, ultra-quiet LPG generator?

Since the OP has sound constraints, while they are quiet, it is a Generator and the sound depends on loading. I have ran the Yamaha EF2000iS and the Honda EU2000 side by side with the exact load at the same time. The Honda seemed to win that battle because the Honda turned less rpm's to deliver the same output. 1 or 2 DB may not sound like much, but it huge at times depending where the generator is located. By the way, I never saw that Yamaha again, the next week, that guy had a Honda.

Their numbers, not mine.

Honda EU2000 59 dB @ rated load 53dB @ 1/4 load

Yamaha EF2000iS 51.5 dB to 61 dB – ¼ rated to rated load


Honda EU 3000I 58 dB @ rated load, 49 dB @ 1/4 load

Yamaha EF3000iS 53 dB – 60 dB @ rated load

I ended up with a pair of Honda EU 2000 's because of weight. The EU 3000 is 143 lb, fueled and would been better in some ways, but I couldn't have secured it and bigger to lift ( I am old ) . Now, after using the pair, they are the best, you can let one idle all day with a smaller charger and run 7 + hrs on a gallon of gas and it's much better than letting it scream maxed out @ 2 hours a gallon. Then when you need more power, you just start the other one and pair them. You also have redundancy and you can keep the run time divided between them. I have them set up on one extended run 10 gallon tank.

A few of my "closest friends" , I know quiet and so do they. We call them the Red Man. If you showed up in this crowd with a Chinese KO, it would be removed and you would get $900 cash and a note on your table that said " This contribution is to help through your financial hardship, please use it to buy a real Generator ".

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BB.

Re: Suggestions for a smallish, ultra-quiet LPG generator?

Remember that a generator may run for >8 hours--And a BBQ runs for 1-2 hours maximum. It is those multi-hour draws from the propane tank that cause you problems. Even moderate draws over 8 hours will freeze a tank in warm weather (I used to watch the tar and gravel roofers and their relatively large propane tanks would all be pretty much 1/2 full with frost on the tank walls keeping their tar pots hot).

5-20 gallon tanks may not be able to keep up with 8 hours of vaporization (guessing--not my field of experience).

-Bill

Vic

Re: Suggestions for a smallish, ultra-quiet LPG generator?

Also, most of us BBQ in warmer weather. Gensets often need to run is some of the most hostile weather. And as BB Bill mentioned, in a power outage, runtimes can be L-O-N-G which increase the chances of freeze-up.

FWIW, Vic

westbranch

Re: Suggestions for a smallish, ultra-quiet LPG generator?

In the winter of '74 we lived in a mobile home that had a propane furnace, fed from a monster tank, about 3 feet diameter and 10 feet long or so. NEVER froze when the temps dipped below -40F for 3 weeks...