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-   -   How to choose a generator for home backup (http://www.diychatroom.com/f18/how-choose-generator-home-backup-162082/)

mikemcd 11-03-2012 10:53 PM

How to choose a generator for home backup
 
I live in NJ, and as you might guess, I'm quite accustomed to flashlights, warm clothes 24/7, and the hum of other people's generators these days. And I'm done being without any means of powering my home during these blackouts. Sandy is the 3rd big storm we've had here in 14 months that took out power to my area for more than just a few hours.

So I want to get a generator, but am clueless about where to start with figuring out what I need. I'd appreciate any help in deciding what is right for my house and how to go about getting this ready for the next storm.

I'd like to at least heat my home and get power to the living room and 2 bedrooms. My house is heated by a Peerless Boiler.

How do I determine what sort of generator I need? What kind of things do I look for in a generator? Should I be concerned about things like how loud it is, fuel efficiency, etc? Or is it more about just power output and nothing else?

Not really needing a generator for anything more than home backup power, do I go with a portable unit anyway or look at built-in units?

joed 11-03-2012 11:04 PM

You need to start with a load calculation to see what size unit you need. List all the things you NEED to operate(furnace, fridge, sump pump, emergency lights, etc.) and the things you WANT to operate(TV, PC, lights). Find the wattage or currents of each device and add them up.

Missouri Bound 11-03-2012 11:08 PM

Generac Power Systems - Generator Sizer

You could start here figuring out the size you need. If it's convenience you want you may want to seriously consider a standby type. If the power goes out, it goes on....period. It will be more costly, but it's there to back up the essentials even if you aren't there.:yes:

sublime2 11-03-2012 11:19 PM

Check out youtube.
Search,
" how to install a generator ". You will see that its not that difficult. Some also have modified outdoor storage bins to house their generator. Backfeeding the panel with an interlock or a transfer switch.
DIY'ing it,I'd suggest the backfeed method.

Here's one,https://www.youtube.com/watch?v=n7Dk...e_gdata_player

AllanJ 11-03-2012 11:32 PM

Yes the noise level is important if homes in your neighborhood are close together.

You need to figure in additional wattage capacity for appliance startup. (A generator that powers only lights does not need such a margin of extra capacity.)

On average, a larger capacity generator will consume more fuel per hour than a smaller capacity generator for the same load when low. But you may have no choice in this matter given the highest electrical load you need to or wish to use.

I don't know how to calculate the reserve wattage needed and this probably renders my entire reply useless.

dmxtothemax 11-04-2012 01:24 AM

Quote:

Originally Posted by mikemcd (Post 1044241)
I live in NJ, and as you might guess, I'm quite accustomed to flashlights, warm clothes 24/7, and the hum of other people's generators these days. And I'm done being without any means of powering my home during these blackouts. Sandy is the 3rd big storm we've had here in 14 months that took out power to my area for more than just a few hours.

So I want to get a generator, but am clueless about where to start with figuring out what I need. I'd appreciate any help in deciding what is right for my house and how to go about getting this ready for the next storm.

I'd like to at least heat my home and get power to the living room and 2 bedrooms. My house is heated by a Peerless Boiler.

How do I determine what sort of generator I need? What kind of things do I look for in a generator? Should I be concerned about things like how loud it is, fuel efficiency, etc? Or is it more about just power output and nothing else?

Not really needing a generator for anything more than home backup power, do I go with a portable unit anyway or look at built-in units?


Do you know how much power your boiler system uses ?
Do you need just 120v or 220v or both ?
What about your refrigerator ?

jeffsw6 11-04-2012 05:05 AM

Quote:

Originally Posted by mikemcd (Post 1044241)
How do I determine what sort of generator I need? What kind of things do I look for in a generator? Should I be concerned about things like how loud it is, fuel efficiency, etc? Or is it more about just power output and nothing else?

Your choice of fuel is really important. I think people who buy generators and then fuel them using utility gas are putting a lot of trust in the gas company, for example. Decide if you want to store your own fuel and how many hours (or days) of fuel you want to have on-hand before you need a delivery or a run to the filling station for diesel. Don't count on getting more fuel being as simple as making a call and waiting a day, because it's not.

Also, if you get diesel, be sure you can lock your fuel tank. People steal fuel these days. If I lived in NJ/NY right now and I saw a house with a big tank full of diesel and I needed some diesel to keep my family warm, I'd steal from you! Lots of people would steal your fuel even on a normal day though, if they knew it was there to be taken.

Quote:

Not really needing a generator for anything more than home backup power, do I go with a portable unit anyway or look at built-in units?
If you live in an area that really cares about enforcing its building codes, you might have to jump through a few more hoops to do a permanently-mounted generator than a portable one. To have a permanent one you will need a concrete pad similar to what you'd pour for a hot tub. If your neighbors don't want you to have one, or you just want it to look nice, you might also need to put in some landscaping around it. Some jurisdictions will require a fence or other access barrier.

Portables can be pretty big and heavy though, especially when fueled up. I rent 20kW generators a few times a year and they weigh like 1000# with a day of fuel, so you really need a truck to move them around -- which means if you want it in your back yard, you need to be able to access your back yard with your truck in such a way that you can maneuver the generator/trailer.

Portables tend to cost more than permanent generators, especially for the ones with nice enclosures and mufflers that make them tolerable to run. A 20kW portable that is quiet can easily cost $20k or more. I'm sure you have seen permanent ones much cheaper.

You'll want to ask your utility about their requirements as well. Some will not fix your power after an outage if they notice you have a generator and the installation has not been inspected. It's not a money-grab, they want to make sure your lock-out switch works so you they don't connect you while your generator is running, otherwise it could be damaged badly, along with your appliances, etc.

Personally, I have a small 6500w generator and it has kept me from having to abandon my house during an ice storm which left me without power for quite a few days. 6500w is not enough to run my heater but it runs electric blankets and a couple of space heaters just fine. There are ways to make your energy use more efficient -- if less convenient -- in order to reduce the size of generator you need and the amount of fuel you have to store. Would I like to have a 30kW generator for my house? I guess so, but I'm not sure I'd want to deal with the fuel headaches.

There's my $0.02. Best wishes to you and your neighbors as you deal with the storm.

kbsparky 11-04-2012 05:21 AM

Would you want to be able to operate your central A/C? Water heater? Electric range?

Is your boiler natural gas fired? You could get a genset that uses the city gas service for fuel. If you have lots of gas appliances, then a small (7-12kW) unit would probably do just fine.

My house is all electric, and I have a 12 kW unit. But it won't run the heat pump in winter. It will run my central A/C in summer, however.

I manage the rest of the heavy loads manually.

allthumbsdiy 11-04-2012 05:38 AM

Mike-

I share your concern as today is Day #6 without power (and based on the number of transformers that are still on the ground in my neighborhood, I expect it to be another week or so).

I have never had the opportunity to use my generator on a long term so this experience has reveled lots of flaws in my thinking of backup generators.

Once life returns to normal, I plan on checking out a natural gas powered, standby generator as my primary backup power so I don't have to wait in hours-long line to get gasoline.

As a secondary backup, I would hold on to my Briggs and Stratton 5500 watt portable generator (gasoline) but purchase a conversion kit to run either propane or gasoline. I would then have about five, 20 lb propane tanks on hand as the primary fuel source as propane shelf life is something like 10-15 years compared to gasoline's 30 days. Of course, I would rotate these tanks by using my BBQ grill time to time.

BTW, if you can wait, I would NOT buy a used generator on Craigslist right now. I guess lot of people got their power back yesterday because I saw a ton of generator for sale. What pisses me off is that rather than selling these slightly used generators at cost or even below cost, they are marking up hundreds of dollars!

raylo32 11-04-2012 07:57 AM

You don't need to buy a specific natural gas generator and keep another one to use with gasoline or propane. These guys sell kits that convert many existing generators to tri-fuel (gasoline, nat gas, and propane). So it will run on whatever you have around.

Natural gas should be good after just about any emergency unless you live in an area like those barrier islands where even that can be compromised by a serious storm surge. So having some propane around as a backup might make sense.... assuming your house is still there and habitable in the aftermath.

http://www.propane-generators.com/

Their web page isn't the greatest but the conversions kits are excellent. Don't expect rapid service anytime soon, tho. They are a relatively small operation and get seriously backed up after every major storm event as demand spikes.



Quote:

Originally Posted by allthumbsdiy (Post 1044351)

Once life returns to normal, I plan on checking out a natural gas powered, standby generator as my primary backup power so I don't have to wait in hours-long line to get gasoline.

As a secondary backup, I would hold on to my Briggs and Stratton 5500 watt portable generator (gasoline) but purchase a conversion kit to run either propane or gasoline.


Billy_Bob 11-04-2012 12:02 PM

If money is not a problem, then you can get a generator which powers your entire home, switches on/off automatically, and runs on natural gas (no worry about gas stations). Just look in the yellow pages for generators.

Missouri Bound 11-04-2012 12:31 PM

Quote:

Originally Posted by allthumbsdiy (Post 1044351)

Once life returns to normal, I plan on checking out a natural gas powered, standby generator as my primary backup power


Is this something you can do yourself?:eek:

allthumbsdiy 11-04-2012 04:26 PM

Quote:

Originally Posted by Missouri Bound (Post 1044572)
Is this something you can do yourself?:eek:

I am inclined to try it but the stumbling block may be running a gas line to it's final location next to my main load center (about 60 feet, traversing through the family room and garage.

Another option will be to locate it near the gas line, but that means running 80 feet of service cable and opening up multiple walls.

Perhaps a standby generator was an overreaction, so I am now considering a larger portable generator (something like 12 to 15kw, setup to run tri fuel - natural gas, propane and diesel) along with a wood burning stove insert (to replace my crappy fireplace).

raylo32 11-04-2012 04:38 PM

The gas line is critical. You need to size the line taking onto account the distance of the run and the KW/horsepower of the generator and any other lkoads off the same branch line. You also need to make sure that the service meter can support the extra load.

Quote:

Originally Posted by allthumbsdiy (Post 1044727)
I am inclined to try it but the stumbling block may be running a gas line to it's final location next to my main load center (about 60 feet, traversing through the family room and garage.
.


jeffsw6 11-04-2012 04:50 PM

Quote:

Originally Posted by allthumbsdiy (Post 1044351)
I would then have about five, 20 lb propane tanks on hand as the primary fuel source as propane shelf life is something like 10-15 years compared to gasoline's 30 days. Of course, I would rotate these tanks by using my BBQ grill time to time.

You had better test this setup with one 20# bottle and your fancy new generator on a cold day before you decide to depend on it. When those small propane bottles are cold they won't produce as much propane vapor which is how the fuel actually gets from the bottle to the engine. Larger tanks suffer the same effect but since they are bigger it's not a problem. Several 20# tanks plumbed together could also relieve this problem.

You will want to check into the rate of propane consumption based on your estimated load. You might decide a 20# bottle will only last 8 hours and you may then want to keep more than 5. Propane is not easy to get after a storm -- it's even harder than gas or diesel!


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