# whole house natural gas generators. recommendations, reviews?



## St_Earl (Nov 16, 2011)

we have friends in new jersey who are looking to get a whole house genny that runs off of their natural gas supply and kicks on when the power fails.

i would like to hear what folks have and how they feel about their products/models.
thanks.

i'm assuming that these models provide clean pure sine wave power.
please include this info in replies though.

many thanks in advance.


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## firecracker_77 (Nov 23, 2011)

geesh....this gas forum is terribly unpopular.  i have a woodstove at the office, but am installing a woodstock franklin gas for my wife at home.  you'd think that gas has no purpose on hearth.com based on the amount of activity.

anyhow, i use the generac 8k for a small home 1050 sq ft upstairs / 1050 sq ft downstairs.  i paid $3200 with installation, and this powers most systems in a small home minus central air.  the system automatically fires up every sunday and you don't notice it's running other than the loud tractor like engine out in the yard.  the transfer switch is smooth and unnoticeble.  i would totally recommend them as insurance.  i have a wife and small baby, and notorious water issues, so sump pumps and furnace being operational are not open to discussion.  a small insurance policy if you think about it, and a selling point on a home.  i have no idea how long these last or what the maintenance will be.  we had ours installed in august 2011.  

for a $1,000 or $2,000 more, you can get 14k or 18k generators that power anything.  generac is the standard that i heard of, so i bought that brand.  i'm sure others are good too.


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## firecracker_77 (Nov 23, 2011)

i am an accountant, and not an engineer, so i don't know much about the power created other than the lights don't flicker, and everything in the house operates the same off the generac.


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## jmc56 (Dec 20, 2011)

We're in Connecticut and finally got fed up with weeklong outages courtesy of CL&P on a fairly regular basis -- a problem that's gotten much worse in the last 10 years as opposed to the previous 20. 

We've installed a propane-fueled 20kw Generac with a whole house smart switch, i.e. it's a load shifting switch that compensates if the system gets hit with too many heavy loads at one time. Reality is that's not going to happen because we converted hot water to demand propane (navien). It starts up automatically if there's a power loss and shuts down when there is. Automated self-test, etc. We do have a service contract because I don't feel like keeping up with the relatively minor service.

My sister has the same unit in the deep south and it has handled both their 5 ton HVAC units at the same time along with other appliances. Obviously startup pulls more juice than run. We need power for heat forced air, well, etc. We're dead without it.

FWIW, the same unit is rated at 18KW with natural gas. 

This was a major project, i.e. we didn't have a place we wanted to have a 500 gallon propane tank we we buried it, requiring some desired re-landscaping and a bit of difficulty because rock ledge is close to the surface in that area, requiring us to cover sections of the line with concrete in areas where we weren't quite at the depth for piping with dirt only. 

OUr best estimate is that the tank would run us for a week with a reasonable load. A heavy load might be 4-5 days. A light load more. Those are only ballpark estimates that were part of the process of sizing the tank. 

These are air cooled units. Liquid cooled units are considerably more expensive, but would probably preferable if you expect to run the generator a lot or as a primary part of a solar ten setup. 

The most complicated part of any generator setup is installation of the switch. The whole house is considerable more expensive and time consuming for the electrician. A simpler switch can handle only key circuits and could operate a smaller kw gen fit to the expected load. That could be a permanent installation or use a portable generator connected through the switch.A friend has wired his house for the full on backup, but has a connect for a large portable unit because generators are backordered in some cases for months.


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## jmc56 (Dec 20, 2011)

I should add, re life expectancy. While everything wears out eventually, you're not likely to need to be concerned with replacing a stationary unit for many years. Using the 20kw generac as an example, used as a whole house backup, it is unlikely wear out in normal use as long as it is maintained properly. That is minimal. You're probably talking about using it two weeks a year at the current power company failure rate. It will be very useful in intermittent use for shorter blackouts. It will run one a week for automated self-test.

A key to this I think is professional installation. We used an electrical contractor who does installation and maintenance of the units as a part of a larger business. We were not impressed with some of the generator dealers and were reluctant to get involved in trying to manage electric and generator separately.

If you have natural gas, operating costs will be much lower when he generator is in use. It's important to get the plumbing right and to code so it's safe, etc. 

This is not cheap power with propane, but what is. It's probably cheaper than a week at a hotel and then I'd have to board my dog. 

Diesel sometimes comes up. I love diesels, i.e. I had a MB diesel for years and have operated a small diesel farm tractor for about 20 years. The latter is very efficient and it's possible to get PTO driven generators for mobile power. Not very applicable here. But having used home heating oil at our primary house, which is for practical purposes No. 2 diesel, the price keeps going out and fixed storage can be an issue. The heating oil turns over, expensively. I keep up to 300 gallons of diesel in my equipment building at our other home. You have to stabilize it, filter it, keep water out of it, etc. NG or LP are both easy to use, produced in the US and somewhat less subject to price variations. Gasoline units would require significant storage with more precautions.

Generac is a widely used brand with a good reputation. The 20 KW unit uses a Generac branded engine, but others use Yanmar or with liquid cooling even small automotive engines. Kohler is a first rate generator. Dealer support could be an issue. My impression is that the consumer grade portables generally have consumer grade power, i.e. all 20 hp units aren't the same. It's not that they are bad, just not built for continuous use. As a general rule, the engines in fixed installations are of a somewhat higher quality, even within a given motor line such as Briggs and Stratton.


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## jeff_t (Dec 20, 2011)

FWIW, a friend who sells Generac as a little side business, recommends LP. Yeah, fuel costs more, and a tank may be unsightly, but if it hits the fan you aren't tied to infrastructure. Depends on how much you are into doom and gloom.

Probably unlikely to find a pure sine whole house generator. I have a friend who is a radio geek, and he has a battery charger connected to a bank of deep cycle 12v batteries powering an inverter for sensitive electronics.


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## pen (Dec 22, 2011)

moving this to the DIY - non-hearth advice forum where more of this type of question is asked / answered.

pen


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## seige101 (Dec 22, 2011)

Be carefull when going larger than 12-14kw if you are on propane, They will suck the fuel down very fast even at half load.

12-14kw is a lot of power available for the average house and you should be able to function pretty much like normal if you have some gas/oil appliances, if you are all electric you will have to be a little more conscious about what you can run when some major appliance is running.

I have installed a few Generac units and was please with what appeared to be quality stuff.


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## Bad Wolf (Dec 22, 2011)

As a side question, can you switch back and forth between propane and natural gas?  That would seem the best of both worlds.  You could run for long periods more cheaply on the NG and still have Propane for a limited time if something happens to the NG.  Though if the NG goes down I would assume there are bigger problems.


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## ironpony (Dec 22, 2011)

25kw industrial diesel generator
for the limited run time I dont find the fuel an issue
burn about 5 gals a day continuos run
40 gallon tank
expensive but cheap insurance


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## Agent (Dec 22, 2011)

To switch back and forth, you likely need to to re-tune the engine and/or replace a few pieces.  
The city water department I used to work for had some old Ford straight 6 stationary engines powered with natural gas as onsite well backups.  Pretty sweet to hear them humming along.


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## Retired Guy (Dec 22, 2011)

Just put in a Generac 10KW - natural gas with whole house switch. The switchover from NG to Propane is very simple - one lever on the Generac engine.


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## MaintenanceMan (Dec 22, 2011)

http://www.zillerelectric.com/forums/

Ziller electric is about the best place on the web to learn about backup genny's. Lots of info there. Especially about Generac.


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