Whole house generators

[kooldino]

I'm thinking about picking up a whole house generator. However, I don't have natural gas in my area.

That limits me to gasoline, diesel, or propane. Although a random propane tank in my backyard for a generator may look silly.

I haven't found any whole house generators that run on gasoline. Do they exist?

As far as propane - approximately how large of a tank would I need?

How many KW should suffice for an average home?

 

[Teken]

I'm thinking about picking up a whole house generator. However, I don't have natural gas in my area.

That limits me to gasoline, diesel, or propane. Although a random propane tank in my backyard for a generator may look silly.

I haven't found any whole house generators that run on gasoline. Do they exist?

As far as propane - approximately how large of a tank would I need?

How many KW should suffice for an average home?

It comes down to your intent and load. If you plan on powering the entire house you need to know what the loads are to accurately size the generator. If you plan on only essential items such as water, heat, lights, and accessories you can get by with a much smaller unit.

It also comes down to how much you want to spend so your budget will dictate what you buy.

In my humble opinion, buy what ever you can looking toward long term goals and use. I personally wouldn't consider anything less than 21 kwh. Then again my needs are higher because in my mind if I am going to be on the hook for $6K or more why not power the entire house!

Teken . . .

 

[kooldino]

This one seems nice, but I'd have to get a ~100 gallon propane tank in the back yard.

http://www.electricgeneratorsdirect.com/Generac-Guardian-6051-Standby-Generator/p6952.html

At 50% load, a 100 gallon tank would last me at least 3 days.

It also features some smart circuitry management.

 

[Stuart in MN]

A gasoline generator large enough for a whole house is going to be hard to find, your choices will be diesel or propane. I'd personally go for propane, it will be better for long storage but either way you still need to run them regularly to keep them exercised.

Sizing will depend on how many things you want to keep running during a power outage - the essentials (well pump, furnace, a few lights and outlets) or the ability to run everything. Most generator manufacturers have some information on their websites for estimating the size but you really should talk to a professional to make sure you get one big enough for your needs but not so big you're wasting money. A couple popular brands are Onan and Generac, but there are many others.

Don't forget you also need a transfer switch (either manual or automatic) plus it has to be connected properly by an electrician.

 

[rsanter]

what I would do is run a second 'priority' panel next to your exsisting one. have the generator feed this priority panel and not the whole house

diesel or propane is best. you may be able to find a gas new but most likly older used but I would just do diesel if you dont think you will need it that much

and yes you need to run them occasionally and put the fuel treatment stuff in it

bob

 

[kooldino]

It comes down to your intent and load. If you plan on powering the entire house you need to know what the loads are to accurately size the generator. If you plan on only essential items such as water, heat, lights, and accessories you can get by with a much smaller unit.

It also comes down to how much you want to spend so your budget will dictate what you buy.

In my humble opinion, buy what ever you can looking toward long term goals and use. I personally wouldn't consider anything less than 21 kwh. Then again my needs are higher because in my mind if I am going to be on the hook for $6K or more why not power the entire house!

Teken . . .

Fair point. I just don't know how much I need.

This one is $500 more...

http://www.electricgeneratorsdirect.com/Generac-Guardian-6052-Standby-Generator/p4234.html

 

[kooldino]

Don't forget you also need a transfer switch (either manual or automatic) plus it has to be connected properly by an electrician.

Do the Generacs come with a built in transfer switch?

 

[fitz11]

Do the Generacs come with a built in transfer switch?

The trasfer switch is wired into the house electrical panel, not on the generator

 

[kooldino]

Just spoke to a buddy who installed a 10k and he said the transfer switch was included.

 

[theoldwizard1]

First, go propane. Gasoline and diesel will go bad over time and probably when you need it the most. You can buy propane tanks that can be buried so you don't have to look at it.

The most important issue for a generator is SIZE !

You need to do your home work, or pay someone to do it for you, and figure out just what size you really need. For example, does your house have air conditioning ? Is that a must have when running of the generator or can you live without it in the middle of summer for 2-3 days ? How about 7-10 days ?

How about a well pump ? Sump pump ?


There are a lot of threads on this board about this topic. The most important thing to know is that an oversized generator is a waste of money, twice ! It will cost more to purchase/install and it will cost more to operate.

Without an A/C load, you might be able to get along with a 7kw or less unit. With A/C you had better be thinking 12kw or more.

Also, look into a generator interlock system for your existing main breaker panel. Much cheaper to install but they are not automatic.

 

[Jeff95TA]

Just spoke to a buddy who installed a 10k and he said the transfer switch was included.

It may have been included but it still has to be wired into the house panel. It transfers the power input from the electric company line to the generator line, so it has to be wired in.

 

[matt151617]

You're in the northeast... does your house have heating oil? I'm assuming so if you don't have gas. If so, you can get a diesel generator and run it off the heating oil tank (they're the same fuel). That way you always have a large quantity of fuel on hand and don't have to worry about it getting stale.

Do you really need a whole house generator though? For 1/4 of the price you could get a good sized regular generator and power only the essential circuits... fridge, furnace, sump pump, a few lights, etc. At least in NY, the power seems to hardly ever go out, and when it does it's usually for less than 24 hours. Certainty nothing a basic little generator couldn't handle.

 

[wb2vsj]

I installed a 25KW propane unit for my parents several years back. Generac Guardian. Bought it from HD. Cast was about $7 or 8K. Electrician wanted $4K to install it. My dad and I did it for $250 in parts, disconnects, etc.

At that time it came with 200A Automatic xfer switch.

These units offer automatic weekly exercise modes.

Other than changing the oil and a new battery every few years, it's been very reliable.

It has a built in block heater and I plug that in from Dec to Feb so it has easier starts.


One thing you need to look at is the LRA (locked Rotor Amps) on you AC Units. The first electrician we had come out to size the generator was telling us to ignore the usual Amp rating and look at the LRA - sort of like the current needed to start the A/C unit. Your genny will have to be able to handle that surge. Have two A/C units? (My parents did) Add the two LRA's together.

 

[nehog]

...
I haven't found any whole house generators that run on gasoline. Do they exist?

...

How many KW should suffice for an average home?

1. I'd avoid gasoline, its storage is very problematic, and as well transportation of significant amounts of gasoline to fill the tank(s) would be hard. You'd need a pretty big tank to make it useful, probably be as large as a propane tank. I'd recommend diesel myself, stores for years without breaking down, very safe to store, in fact if you have oil heat you can burn it in your furnace in an emergency!

2. How big is your breaker panel's main breaker? 200 Amp? What loads do you have? Are you planning an automatic start and transfer or a manual transfer setup?

 

[rlitman]

You're in the northeast... does your house have heating oil? I'm assuming so if you don't have gas. If so, you can get a diesel generator and run it off the heating oil tank (they're the same fuel). . .

At least in NY, the power seems to hardly ever go out, and when it does it's usually for less than 24 hours.

Huh, and HUH?

For one thing, I have a diesel generator at work (megawatt sized). I can assure you that diesel fuel is NOT #2 home heating oil.
You can use diesel fuel to heat your house, but using heating oil to run a diesel generator will significantly shorten the lifetime of a VERY expensive investment (diesel generators are much more costly than propane, upfront).
I suppose you could just keep your heating fuel tank full of off-road diesel so as to only have one tank, but it does cost a bit more than heating oil.

Diesel fuel also can go bad in storage (it is nowhere near the issue that gasoline suffers from, but it can and does happen). If you have diesel, you must monitor the quality of the fuel, at least annually.
Propane will store pretty much forever (or at least until your tank rusts through), even long after the odorant settles out.

As for power not going out in NY:
At work, after hurricane Irene, we were out for just under 4 days. Since we are a medium voltage customer, our circuit had priority over residential low voltage circuits, in the after-storm triage situation, and was fixed pretty quickly.

At home, after hurricane Irene, I was making a trip to the gas station every morning for 7 days. The first few days were awful. I had to drive past dozens of gas stations that either had no power (so they couldn't pump gas), no gas, or no phone line to accept credit cards (so they just closed, and didn't even bother to accept cash). I was filling every gas can I had, but stores were completely sold out of gas cans for days (I now have enough cans that I can fill up and run for about three days).

A winter storm in February 2011 (just a few months before Irene) left me in the house with a newborn (home from the hospital just a couple of days) without power. Having a generator was the only way I could keep the heat running in my home for that THREE DAY power outage.
Since I bought my house in 2005, I've had well over a dozen outages that were over 24 hours, and another dozen or so that were more than a couple of hours, that got me to start my generator. I don't have an automatic transfer switch, so when the lights go out, I let the battery backup keep the TIVO and TVs running, I reach for the flashlight, and a couple of hours later I'll start the generator to keep the fridge and freezer cold and keep the hot water hot.

 

[aandpdan]

Just for reference:

I have a 5kw propane powered generator. I burn about 1 gallon/hour with about a 3kw load, my typical "max".

One thing to consider is that most propane dealers will "loan" you a propane tank because they assume you're going to be buying propane from them on a regular basis. If you don't, expect to pay a rental fee (and a higher price per gallon).

Too small a tank, or one low on gas, in cold weather and you may not have enough vaporization to meet your demand. You'll starve the generator of fuel.

Since it sounds like you have an electric water heater and that is one of your concerns, I'd put it on the propane. You can then downsize your generator significantly.

Just running the fridge, freezer, tv, a few lights, the boiler, and even the microwave are not a problem for me.

 

[nehog]

Huh, and HUH?

For one thing, I have a diesel generator at work (megawatt sized). I can assure you that diesel fuel is NOT #2 home heating oil...

I know a LOT of people who will disagree with that. The main difference can be a lubricity additive, but basically #2 diesel is the same as #2 home heating fuel.

Some home heating oil is #2 mixed with kerosene (for outdoor storage tanks) and that is different. However, even that will work if you add whatever is needed to improved the fuel's lubricity.

This is like thinking that one brand of gasoline is 'better' than another. It is all the same except for the additives.

 

[matt151617]

I forgot about the fact they add kerosene to fuel oil. The fuels in their purest form are the same.

Irene was a freak storm... in northern NY the power was out less than 24 hours. One other time in a year and a half we lost power for 30 minutes from line maintence. A well insulated house should hold a comfortable temperature for a few hours, as will a refridgerator hold a safe temperature.

 

[Falcon67]

20kW or therabout gen sets come up for auction around here a lot. Cheap too.

 

[Jim_No_Garage]

Hmmmm. The OP might be offline for a while. South Jersey got clobbered on Friday with a major wind event and power is out in large areas. The same storm got DC and the surrounding areas.

I've a trip to Williamsburg VA planned for late next week - hopefully everyone is back online by then.

Time to fill up the as cans again for me. I'm with RLITMAT - I have a generator that has gotten more use in the last year than since it was bought in preparation for the massive Y2K power outages

Cheers

Jim

 

[zuk123]

I have a generator that has gotten more use in the last year than since it was bought in preparation for the massive Y2K power outages

Cheers

Jim

Yep, me too. Here in TX it's time to fill up the gas cans. I usually fill about half of them and fill the other half when there is an actual storm on the way.

Only problem with my gas geni is that it is too small to start the air conditioner. My wife bought a little window air during Ike. We were dark for 14 days and no water for 3. I had to leave for a business trip to China.

This season I want a whole house natural gas unit.

Can anyone tell me about USING one? I've heard that most of the 18kw and below air cooled geni's need oil and filter changes every 100 running hours. Based on last time, I'd need 4 full sets of spares! That seems really excessive to me. Anyone got the real story?

thanks,

zuk

 

[theoldwizard1]

I have a 5kw propane powered generator. I burn about 1 gallon/hour with about a 3kw load, my typical "max".
.
.
.
Too small a tank, or one low on gas, in cold weather and you may not have enough vaporization to meet your demand. You'll starve the generator of fuel.

Something to think about in cold weather !

Since it sounds like you have an electric water heater and that is one of your concerns, I'd put it on the propane. You can then downsize your generator significantly.

Good suggestion ! OP bill for propane may be less than the cost of running an electric water heater !! Might think about switching the stove and dryer to propane in the future.

Just running the fridge, freezer, tv, a few lights, the boiler, and even the microwave are not a problem for me.

Even with a well and sump pump (note NO electric stove) I'm sure your "average" load is less than 3kw.

 

[jordan369]

I have a Champion 7500/9000 portable generator I use to power my whole house. It works great for what I need it for. I looked at the natural gas option but for as often as its used it was not cost effective.

Mike

 

[Milton Shaw]

I put in a 17K from Northern Tool. I bought a used 500 Gallon Propane tank. At 80% fill that's 400 gallons and I've had it for almost two years and still have not used enough to get a refill. We have had two overnight outages from storms and several a couple of hours or so. It's been nice to only have to wait a minute for the power to come back on. The unit does come on for 15 minutes every week to exercise the motor.

 

[mothgrey]

I had a 20KW Generac installed in Jan. Runs most my whole home and would run it all but I didn't need some stuff on it. SO he move all that I needed to run to one of the 2 150Amp boxes. Of course I believe that now that I have it I'll never loose power for it to need to run. And if that's the case it's cheep insurance. I live in Va and with the storms that hit I did loose power for about 15 min. It came on I didn't even know it was running till I opened the window. I had it put on the other side of the driveway away from the house. I use propane for my one furnace in the house so I have a 1000 gal tank in the ground. The generator did come with the transfer switch and the Nexus unit so it can run a couple AC units if needed it will cycle power to them as it can afford to bring them online. I didn't use it because I only needed the one AC unit on it.

 

[mothgrey]

Hmmmm. The OP might be offline for a while. South Jersey got clobbered on Friday with a major wind event and power is out in large areas. The same storm got DC and the surrounding areas.

I've a trip to Williamsburg VA planned for late next week - hopefully everyone is back online by then.



Jim

I was there today and I think they are back on line. North and West were hit hard. Have someone on my team is being told will be out till next week. Out in Lynchburg.

 

[kooldino]

You're in the northeast... does your house have heating oil? I'm assuming so if you don't have gas. If so, you can get a diesel generator and run it off the heating oil tank (they're the same fuel). That way you always have a large quantity of fuel on hand and don't have to worry about it getting stale.

Well, I have an oil tank in the basement and I have a propane tank about 100 feet away from where I'd want the generator. Would running a propane line that far be feasible?

Do you really need a whole house generator though? For 1/4 of the price you could get a good sized regular generator and power only the essential circuits... fridge, furnace, sump pump, a few lights, etc.

That's true, but I want something that kicks on automatically.

At least in NY, the power seems to hardly ever go out, and when it does it's usually for less than 24 hours. Certainty nothing a basic little generator couldn't handle.

My power goes out once a month. It's pretty annoying.

 

[kooldino]

1. I'd avoid gasoline, its storage is very problematic, and as well transportation of significant amounts of gasoline to fill the tank(s) would be hard. You'd need a pretty big tank to make it useful, probably be as large as a propane tank. I'd recommend diesel myself, stores for years without breaking down, very safe to store, in fact if you have oil heat you can burn it in your furnace in an emergency!

Understood.

2. How big is your breaker panel's main breaker? 200 Amp? What loads do you have? Are you planning an automatic start and transfer or a manual transfer setup?

Yes, 200A. I'm not exactly sure what my loads are, but I'd like to be able to run the following:

1. Lights in a few rooms
2. A computer or two
3. A TV and DVD player
4. A/C or heat
5. refridgerator
6. toaster oven or microwave
7. Having the ability to still use some 220 appliances like a dryer or a welder intermittently would be nice.

 

[kooldino]

I was there today and I think they are back on line. North and West were hit hard. Have someone on my team is being told will be out till next week. Out in Lynchburg.

Most of us are back online, not all of us. 206,000 homes lost power from a half hour storm that no one saw coming.

I still don't have cable.

Saturday here was a total war zone.

 

[rlitman]

Can anyone tell me about USING one? I've heard that most of the 18kw and below air cooled geni's need oil and filter changes every 100 running hours. Based on last time, I'd need 4 full sets of spares! That seems really excessive to me. Anyone got the real story?

It depends on the RPM and lubrication system more than the KW.
5 hours is pretty much the break-in for all, for the first oil change.

After that, on smaller units that are 3600 RPM, splash lubricated, think of a 50 hour oil change interval, not 100 hours.

On mine (1800 RPM, pressure lubricated NA gasoline), I change once a week (168 hours), but could probably get away with twice that. Note that after about 3 days I will have had to top it off by around a quart, and just change it entirely after a week.

At work, (1800 RPM turbo diesel) the change interval is 600 hours, but I'll have to top off each engine with around 1.5 gallons every 96 hours of runtime.
To get to that kind of runtime though, that generator has two huge full-flow filters, plus one bypass filter, and 13 gallons of oil in the sump.

 

[zuk123]

Thanks RLITMAN, I wasn't even aware that there were different lube types, or that it affected service intervals! So learning that was a good thing.

I'm gonna guess that the cheaper units have more frequent service?

Every 50 hrs would definitely be an inconvenience as even 100 would be a pain.

My disaster plan is in phases, and doesn't really even kick in hard until after the second week, so I'm assuming 14 days of run time as a minimum for planning purposes. 21 days would mean that the storm was so widespread that the local utility was still working high priority cases, which is not super likely. At that point we are in survival mode, and transitioning out of town is a real option, so minimum 2 weeks, max 4, for planning sake.

The less attention the geni needs during what is a high stress time, the better.

thanks again,

zuk

 

[theoldwizard1]

Yes (I want auto start and transfer), 200A (Main Panel). I'm not exactly sure what my loads are, but I'd like to be able to run the following:

1. Lights in a few rooms
2. A computer or two
3. A TV and DVD player
4. A/C or heat
5. refrigerator
6. toaster oven or microwave
7. Having the ability to still use some 220 appliances like a dryer or a welder intermittently would be nice.

If you want an auto start and whole house auto transfer, you will have to size the generator to the largest load that could automatically start. This means you have to assume the A/C is running and the water heater as well as well and sump pumps. All of those other items are so small (relative to what I just listed) that they don't mater. This will likely push you into the 20kw and up range.

Even with 20kw, if someone turns on the dryer or the stove without turning off the water heater or A/C your going to trip the main breaker on the generator. If you don't want that concern you will be looking at 30kw or more.

Remember, you pay for larger generators twice. First when you purchase and install them and second every time it runs. Bigger units consume more fuel even when running at much less than the full load.


I don't see a problem with running a properly sized and installed propane line 100'.

 

[theoldwizard1]

My disaster plan is in phases, and doesn't really even kick in hard until after the second week, so I'm assuming 14 days of run time as a minimum for planning purposes. 21 days would mean that the storm was so widespread that the local utility was still working high priority cases, which is not super likely. At that point we are in survival mode, and transitioning out of town is a real option, so minimum 2 weeks, max 4, for planning sake.

I can't find any specs for recommended oil change interval on home generators, but all of them now have low oil sensors, spin on oil filter and require synthetic oil.

I would stock 3 or 4 sets of spares.

 

[mx842]

My buddy has two 25kw gen sets at his farm, one for his house and one that takes care of his kennel and barn. They both run on propane and those suckers will **** down some fuel. They will use the same amount with summer loads as in winter and if the power stays off more than 3 days they would drain his 500 gal tank dry before lunch time on the third day. He had another 500 gal tank installed and now he's good for about a week at most. Around here the power rarely stays off more than a week at a time, I think we had a ice storm several winters ago and it was out for 10 days but for the most part 3 or 4 days max. The problem is the cost of running these things, he gets a discount on the propane because he buys over 500 gal at a time but still it's nothing for him to put 15 to $1800.00 in those tanks after an outage to fill them up especially with the price of propane these days.

 

[mx842]

I had a 20KW Generac installed in Jan. Runs most my whole home and would run it all but I didn't need some stuff on it. SO he move all that I needed to run to one of the 2 150Amp boxes. Of course I believe that now that I have it I'll never loose power for it to need to run. And if that's the case it's cheep insurance. I live in Va and with the storms that hit I did loose power for about 15 min. It came on I didn't even know it was running till I opened the window. I had it put on the other side of the driveway away from the house. I use propane for my one furnace in the house so I have a 1000 gal tank in the ground. The generator did come with the transfer switch and the Nexus unit so it can run a couple AC units if needed it will cycle power to them as it can afford to bring them online. I didn't use it because I only needed the one AC unit on it.

A tree fell on my old genny last fall when Irene came calling. It was an old coleman 4450 and it would run the main survival things like lights, well pump and fridge forget about the AC. I bought a Generac XG8000E and man that thing is sweet. I finally got a chance to try it out last week when we had all those bad thunder storms roll through and that thing kicks azz. I fed my 200 amp panel with a #10 4 wire cable plugged into one of my welder plugs and I think this thing could dam near run the whole house. When I first turned it on I just had the well pump, lights, kitchen rec(for coffee maker) and fridge on and that didn't phase it so I turned on the heat pump and I got a little bump out of the governor and the load lamp was only showing 1/4 bars. I checked the Amp load on each of the line wires at the panel breaker and with these things running I was only seeing 11 amps draw. I didn't try the washer/dryer because the power was only off for about 12 hours but I believe it would have run those also if needed.

I have a gas range sitting on the side porch just for times like that so I wouldn't have to run the kitchen range at all. Other than those things, what else do you need? If something really serious happens and the lights stay out for more than several weeks to a month everybody is going to be in the same boat because no one will be able to get fuel for anything.

 

[theoldwizard1]

Wow !

I did a quick price check on whole home generators.

30KW - about $12,000
20KW - about $5,000

I would switch my water heater, dryer and stove from electric to propane.

Propane and natural gas are MUCH more efficient at heating as compared to electric that the OP might have a lower monthly average utility bill !

Actually, OP might want to investigate ground water heat pump heating/cooling system. Much more efficient that an oil burner and A/C.

 

[nehog]

...
That's true, but I want something that kicks on automatically.
...

Do make sure you understand the rules about automatic backup power supplies! There are rules about sizing of the generator and the transfer switch that if you must meet NEC codes you will have to address.

 

[aandpdan]

I fed my 200 amp panel with a #10 4 wire cable plugged into one of my welder plugs and I think this thing could dam near run the whole house.

Great, you know it works. Now do it right and put in an interlock.

 

[Stuart in MN]

A common solution is to move the essential circuits to a small subpanel mounted next to the main panel, and then use an automatic transfer switch for just those loads. That way you minimize the size of the transfer switch and genset.

 

[Dragster Racer]

I have a 3500 that I use at the track all the time. All I would need to run to get by at home is well pump and furnace blower and fridge. What is the simplest way to hook up? I actually have an access box under the meter. I could pop the meter face off for safety, but it would be nice to have it simple enough and safe enough that my wife could do it. It would also be nice to know when the line power came back on, as I have no view of neighbors.
I have done a bunch of electrical, in fact wired the house. But no experience with wiring in a geni drop.