Natural Gas Generators

I'd really like to put one of these whole house gens at my place. I have a couple good places, one uses Kohler and one is Generac. The Kohler place would be able to do everything, gas, electrical, etc... which to me is an advantage. That and I really like their outfit.

A lot of money though, and I have several things I need to replace. :sigh:
 
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RevB said:
...manage temperatures by running rich of peak using fuel to cool or lean of peak using air to cool....something any carbureted engine will not be able to take advantage of. Aircraft have the added advantage of adiabatic lapse rate cooling as altitudes increase.

Went way to far with this.....
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Worth noting that a nat gas generator is using a fuel that's already in gaseous phase. A gasoline unit does throw off heat vaporizing liquid gasoline into vapor.

scurries off to lookup some data

Heat of vaporization for 10% ethanol blend is about .43KJ/gram

Heat of combustion for 10% ethanol blend is about 46KJ/gram.

So... a 1/100 ratio.

So... we are cooling the carb, intake air, and some other items to a small degree.
On one hand... we are cooling the engine a little.
On another hand, we are cooling the incoming air charge... increasing density... leading to MORE air/fuel coming in... increasing heat (after combustion) even more.

It's been a while since I did any differential equations and combustion math... so I'm going to stop here and leave it up to y'all to speculate about.

I do know that my 35 briggs/diahatsu carb on my mower gets cold enough, even on 95F days, to condense water and drip a small, but steady, series of drips onto the engine.
 
Pretty glad I have my Generator right about now since I'm in Houston

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@IReallyLikePizza2 : I am looking at going the gen route soon and want to know from you (since you are close by): any words of wisdom for me?

Would you still but the Generac if you had to do it over again?
Would you go a little larger?
Any gotchas that you can advise me on?
Would you recommend the company that you purchased from? Installed by them?
What about the monitoring app? Would you still build your own with a Pi?
What about the service contract? Any opinions here?
 
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ptzman said:
My power was out for eight days and my liquid cool natural gas 20kw Winco generator did not break a sweat in 90-degree weather. I do not think an air-cooled generator would have survived. Air cooled engines are not made to run continuously. I purchased this generator off of Ebay with less than 300 hours with the transfer switch a few years ago for $1100 plus shipping. My generator has a Ford four-cylinder motor in it. I installed it myself.
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Guess you better tell all those private pilots flying Lycoming, Continental, big radials, etc. they better stop flying those unreliable air cooled powerplants.
 
samplenhold said:
@IReallyLikePizza2 : I am looking at going the gen route soon and want to know from you (since you are close by): any words of wisdom for me?

Would you still but the Generac if you had to do it over again?
Would you go a little larger?
Any gotchas that you can advise me on?
Would you recommend the company that you purchased from? Installed by them?
What about the monitoring app? Would you still build your own with a Pi?
What about the service contract? Any opinions here?
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Sorry, I missed this!

Would you still but the Generac if you had to do it over again?
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Thats a good question. I would never go Generac air cooled, only liquid cooled. And right now the model I have is in limbo because of engine supply, apparently its making a comeback.

I really do think Kohler and Cummins make a better unit in total, the problem is Generac has full Genmon support, which is so cool. Also, there are so many Generac's out there that generally issues are well known and easily fixed. After Beryl there were plenty of forum and reddit posts about people with Kohler generators having issues with dealers that had no clue how to resolve.

So, to answer your question, my brain says no I would not go Generac, but my gut says thats what I would end up with again.


Would you go a little larger?
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I don't think so, largest load without charging my wifes EV was 14kw, so I don't really need it. But, if I were going Generac today, the new XG 32kw would be what I would get

Any gotchas that you can advise me on?
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For this Generac or the whole idea of an NG genset?

Would you recommend the company that you purchased from? Installed by them?
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It was Generator Super Center in Houston, and no not really. They didn't really do a very good job on multiple things. This was right after the Texas 2021 freeze so I just wanted it done, and just accepted I had to fix some things myself.

What about the monitoring app? Would you still build your own with a Pi?
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10000%

What about the service contract? Any opinions here?
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Complete scam IMO, the only good thing to buy would be some kind of extended warranty if you can get it without a contract. Maintenance is easy and should be done yourself, so that when you need to do it during a storm, you know how
 
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RevB said:
Guess you better tell all those private pilots flying Lycoming, Continental, big radials, etc. they better stop flying those unreliable air cooled powerplants.
Click to expand...

Oh boy, not this again.

An air cooled airplane engine is very, very different to an air cooled 3600rpm budget genset.
 
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Our Kohler 18k developed unstable rpm control after about ten years. Would seek up and down incessantly. Service crew replaced multiple parts and could never resolve issue which seems to be endemic to its design. Replaced with Cummins 18k and that has been a solid performer.
 
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guykuo said:
could never resolve issue
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I think this is the issue with Kohlers, for every Kohler here in Houston there is 100 Generac's

Much easier to diagnose a common issue on an F150 than a Ferrari

If I could go back and get the Cummins RS25 I would, nice Genset, but the installers around here all sucked so it was never in the cards
 
Any gotchas that you can advise me on?
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For this Generac or the whole idea of an NG genset?

The whole idea of an NG genset. Like things that you did not think of until you were in the process of having it installed or after installation and trying to run it. "Gee, I wish I had known about..."
 
samplenhold said:
For this Generac or the whole idea of an NG genset?

The whole idea of an NG genset. Like things that you did not think of until you were in the process of having it installed or after installation and trying to run it. "Gee, I wish I had known about..."
Click to expand...

Really nothing that I thought of after the fact, because I really did my homework but here is some good ideas in no real order, I may reply back and add more as I think of them

  • I think its a good idea to also have a manual interlock on your main panel. This way you can run on a portable generator if you wanted to like when you change the oil in a storm.
  • Your loads really need to be as balanced as possible. Most generators can only support an unbalanced load to 25% of generator capacity. So if you have a bunch of stuff on Leg A in your panel and nothing on Leg B, you could run into issues. I re-arranged some breakers to get it matched nice
  • Keep plenty of oil and filters stocked!
  • Don't buy the OEM filters, cross reference to FRAM or whoever you want. a Fram Ultra for my Gen costs $7, a Generac filter costs $30... That adds up
  • If you go air cooled, do not run 5W-20 like they say in the book now, stick to 5W-30 or even 5W-40. 20w is too thin for the hot temps we get here in Texas
  • Make sure do do a weekly exercise, don't set it way far back like some people do, like every 6 weeks
  • At least every 6 months or so, do a good LOADED test and get it good and hot, to burn off any moisture
  • Do not stick to 200 hour oil intervals as most will tell you for the air cooled gensets. Per the book in the small text, it says under extreme conditions you need to do 100 hour, and Texas summer counts as extreme
  • For air cooled, watch for oil leaks where the generator end meets the engine
  • For the liquid cooled 2.4l units, keep a spare mag pickup on hand
  • For the liquid cooled units, 125 hours for an oil change is overkill, you can go to 200 easily
  • Most common reason for a failure to start is the generator. Keep on top of that!
  • Lost of generator installers ignore gas pressure and pipe sizing. Make sure you have enough gas, and upgrade your meter if needed
  • Get a shutoff on the gas towards the house if you don't already, if you have a tree through your house busting a gas line, you don't want to have to shut off gas and the generator


I'm sure I can think of more, I'll keep replying back
 
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I ran Ethernet out to my 24kw Generac so I could install a RPi out there and run genmon on it. Genmon is great for getting metrics out of the generator and scheduling exercise times. You can extract metrics from the Gen with genmon and used Grafana to build pretty graphs.

Grafana

snapshots.raintank.io snapshots.raintank.io
 
Honestly I would be tempted to stick to Generac JUST FOR GENMON!

Its awesome. Though they are adding support for other brands slowly
 
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@samplenhold I think he means the most common reason for a failure is not starting the generator ( periodically)
 
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I live in Texas so I also do our yearly 200 hour test when Centerpoint screws up :rolleyes:
 
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