# Most fuel efficient generator for specific use?



## catalekid (Jan 23, 2011)

My small AC unit pulls 50/ 520/ 583 watts on fan only, compressor running and compressor startup. I am looking for the most fuel efficient GASOLINE powered generator $1000 or under that will run this AC unit and nothing else.

So far my answer is the Honda 1000EU .................. anybody have a better suggestion?


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## jimbo913 (Jun 18, 2015)

That would be your best choice in regards to the job, durability, fuel efficiency and ease of use.


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## Harry Chickpea (Dec 19, 2008)

I am extremely suspicious of that 583 watt startup figure. The common estimation of inrush is twice running current. Not sure how you measured it, but I would bet that meter weighting gave you an inaccurate read. SOME ACs will struggle over the hump with lower power, but not all.

The Honda is priced around $900 to $1000. Harbor Freight has a clone that is a little noisier and an actual capacity at 1900 watts, but has the same economiser. Cost $500 That difference in price will buy a lot of gasoline if you are looking to save money.

I have a nominal 2000 watt open frame generator that I bought for $100 (from Aldi's of all places) specifically to run a room AC in extended power outages, and for use with small power tools, but it is a bit noisier and obviously not as fuel efficient.

Don't even think about the 900 watt 2 cycle cheapies. They are ok for incandescent lights and fans and not much else.


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## GREENCOUNTYPETE (Jul 25, 2006)

unless gas is a very high priced commodity for you or you plan to run this a lot of hours , a larger generator at a lower cost will probably server your budget better 

Generac is a Wisconsin company that makes generators that have made a good name for themselves as durable 

they are sold nation wide and there are parts and service available for them http://www.northerntool.com/shop/tools/product_200369672_200369672
this one specs 10.25 hour run time


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## EDinTN (Sep 8, 2014)

I'd go with at least a 2000-watt inverter generator.


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## Steve_S (Feb 25, 2015)

I second EDinTN with going for a 2000 Watt Inverter Generator. You don't want to push any genny to the max limit and an AC can pull an awful lot at startup and the cycling on/off. Of course when the power is there at your fingertips, someone always has "something" that needs to be plugged in for whatever reason. 2Kw vs 1Kw you won't use much more fuel but have the reserve there when you will inevitably need it.

Honda, Generac, Yamaha, Hyundai, Lifan all make good Inverter Generators with Honda & Generac being at the top end (price & quality). The KEY ISSUE is *Low Oil Shutoff* not just a Low Oil Indicator (often missed till too late, resulting in major "Drunken Sailor Talk").


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## catalekid (Jan 23, 2011)

I thank you all for your replies .................. durability is VERY important as I will be living in this cabin for many years ................. the wattage reading came first from a a Kill A Watt but was later confirmed by a licensed electrician who was also skeptical of my numbers


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## Gary in ohio (May 11, 2002)

catalekid said:


> I thank you all for your replies .................. durability is VERY important as I will be living in this cabin for many years ................. the wattage reading came first from a a Kill A Watt but was later confirmed by a licensed electrician who was also skeptical of my numbers


A kilawatt meter and a most licensed electricians are going to be able to see inrush current. Its quick and happen only at startup of the device/fan. You typically double your genset capacty it handle those spikes. Also note most generators have a running and a peak capacity rating for those inrush devices.

The 1Kw honda would be a good option.


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## Mupwi (Jul 14, 2014)

remember the inrush current is during the time while the motor is getting up to speed unless it has a variable speed drive on it this is normally less than one revolution so that spike in current is there for only about .05 of second so would be difficult to see on most meters


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## Darren (May 10, 2002)

I'd look for a used EU2000. Should be able to find one for that price if you're not in a hurry.


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## JeepHammer (May 12, 2015)

What I saw listed was 'Lawn Mower', high RPM engines and very small genrator frames.
I've tried these, and they are short lived, noisy and generally a waste of money over the long term.
I rarely got more than one season without the smaller units needing repair, and that got expensive quick, not to mention its broken when you need it.

The fuel cost per unit of power, run time costs, will level out around 3,500 Watts.
Under 3,500 watts, you fuel cost will be higher.
There is economy in scale, the smaller, the more expensive to run.

If you have mechanical abilities, then look for a larger, low RPM or vairable speed genset.
New, they can be expensive,
You can find them used from insurance sales, and every larger RV has one, and they are in salvage yards all over the place.

You will also find dealers & service centers have used units and 'Rebuildbles' that are cheap.
The engines on these larger units are rebuildable by any small engine shop,
They are often overbuilt for the application, and that means reliability in your favor.

The larger ones 'Idle Down' when current demand is down and save a lot of fuel.
They are almost always equipped with low oil shut down, over heat shutdown, and use rebuildable/rewindable generators, along with using commonly available parts that are much less expensive.

I purchased 12,000 watts of Onan low speed gasoline generator for $700
That genset has an oil filter (huge longevity deal) built in low oil and over temp shutdown,
Produces in 110 & 220 volt AC, 60 cycles, just like normal 'Grid' power,
And so far its cost me a carb kit, an air filter housing, a fuel pump diaphram & a carb rebuild kit in the last 12 years,
And its still running strong.

This was an RV pull purchased from the dealer that sold the newer, larger genset to the RV owner.


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## thestartupman (Jul 25, 2010)

One thing you need to consider, is that if you try to find a small generator that will run your current A/C, you never know if your A/C needs replaced , if you new one may push the small generator past it's limits.


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## Harry Chickpea (Dec 19, 2008)

Another option might be rigging up an AC from a small car to be motor driven. There are multiple efficiency losses in the current system. Change from rotational mechanical energy to DC power, change to AC in inverter, change from AC to rotational energy in compressor.

Edit to add: The harbor freight honda clone is priced at $400 this weekend with a HF coupon.


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## Nimrod (Jun 8, 2010)

catalekid said:


> My small AC unit pulls 50/ 520/ 583 watts on fan only, compressor running and compressor startup. I am looking for the most fuel efficient GASOLINE powered generator $1000 or under that will run this AC unit and nothing else.
> 
> So far my answer is the Honda 1000EU .................. anybody have a better suggestion?


A 5000 BTU AC draws about 520 watts at 120 volts when it is running. Your generator needs to be more than double that because the AC will pull double when the compressor is starting up. 

A generator will be most efficient when it's supplying near it's rated current.

Inverter generators are supposed to be more efficient, quieter, and produce cleaner power than non-inverter ones. You are on the right track suggesting the Honda 1000EUi. The Honda 2000EUi is about $1100 and I think you will need the extra power. Yamaha, Ryobi, Generac and others make inverter generators for less money than Honda. 

Look for a generator that will power your AC for at least 8 hours so you can get a good night's sleep. 

Sweet dreams.


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