Shed to house a generator

[Tom Fischer]

I just bought a Generac 17.5Kw generator. Up in New Jersey here, and the recent hurricane//power outage 2 months ago had the Missus looking mighty cross.
Anyway power goes out at least once a year here, mostly mid-summer when the trees are very heavy. Often stays out a few days.

I would like to store the Generac outside, and it will be near the service panel. My neighbor is the electrician, installs a lot of home generators, he says the location is good.
The base is Pressure Treated 2'X4' cross-tied with lap-joints flat (sleeper), screwed and TiteBond, very stable. On top of that is a plastic pad, designed for as base for compressors, 4'X3'X3" thick,
To protect the unit from rain (the snow load will not get at it), I was thinking of building a small dog-house size building 4' long X 32" wide X 46" high, framed with cedar 2X2s, and clad with Cedar clap siding, and roof (2 gables for vents), maybe same thing, cedar claps.
The cedar offers the advantage of being very stable, plus light, and good workability. White cedar is very even-grained. Glued up M&T joints on this frame would be very strong. Seems this small building would be well under 80 pounds. I would like to be able to lift the shed up to move it, no winches, chain hoists, etc. If I had to, I could build it in a couple of sections, break apart, or just 4 walls being one piece, plus roof section separate, snaps together (with gate hooks, whatever)
Any reason why this is a bad idea?
Any other suggestions?

tia
tom

[Tony De Masi]

Tom, I have the 17KW generac sitting in a position that sounds very similar to yours. I do not have a cover on mine. As I was reading your post I was thinking what you eventually said, that you wanted to be able to lift it off. You certainly will need to do that for servicing the unit, which I have done once a year. Is it necessary? No. Is it a bad idea? No.

[Anthony Whitesell]

Although I'm not going all out with the whole house generator, I will be purchasing a large portable in the near future. In the summer it can live down the hill in the shed. In the winter it will need to be closer by. I too was thinking of some type of doghouse for it. Here is most of the design forming in my head: A 4x4 PT cube with a roof on it. The sides will need to be removeable and hinged. They need be removed to move the generator and shed come spring (to reduce the weight), and also to be opened when the generator needs to be run. So I thinking of barrel latches to hold it closed, but I need to find a seperable hinge.

My only comment would be to give consideration to extra support on the legs for when you do try to move it.

How are you keeping the snow load off of it?

[Tom Fischer]

Hi Tony and Anthony, I didn't get a whole house generator either. The one I bought has 2 wheels (no permits required). First thing I did, got rid of the stationary foot in the front. Replaced it with a 5" caster. Now it has three wheels.
The PT box would work too, but seems that would be much heavier than white cedar.
I was thinking simple 2"X2" cedar frame: sill and plate, MT joints for all the 2X2 wall studs - four on the length, three on the width. Nails or screws might crack the stock. White Cedar is pretty strong, but brittle.
The snow won't get in there, for the most part. Putting it under the deck. Space between the deck boards is 1/8".
And after talking to the kind folks at my lumber supply, at least one portable generator in town was stolen, during the recent outage, daytime, nobody home. Some people, wow. Times are tough, but that is a terrible thing to do.
So this portable, once it gets under the deck, will be chained to one of the 6"X6" PT posts.

(deck needs to be power-washed :D)

http://farm7.staticflickr.com/6046/6390661395_ed63240ae9_b.jpg

[Anthony Whitesell]

That's a mighty nice deck. If you can put it under the deck and run it in place. I would put it as near the house as possible, remove one of the lattice panels and cut out a section to turn it into a door. Then attach a piece of metal roofing to the bottom of the decks floor joists to cover over the generator so nothing drips on it. I don't see any reason to build additional sides or a separate roof. That was my original plan and may do that instead for summer storage. But unfortunately the side of the deck I can get the generator under is 26+ feet away from the panel and would require 6ga wire to minimize the voltage drop at 30A. With the lattice work sides, the underside stays dry from both snow and rain.

Thanks for the reminder of some people. I'll probably install some type of concrete post and rebar loop to attach the generator to during winter "storage".

[Tom Fischer]

Thanks for the kind words Anthony.
The deck is wooden (IPE) and needs even air flow over and under, keep the deck boards from cupping.
The corrugated roofing would sure keep the generator dry, just not completely sure that the deck boards wouldn't become unstable.
Maybe you're right, it would work.

[Richard Shaefer]

I have had 7.5kW Generac in my side yard in the northern boondocks of NJ for five years now and the all-weather enclosure it comes in is more than good enough. I would not enclose it in a shed, it needs to suck in air from the end for cooling and intake and out the other side for exhaust. They system is designed to be all-weather and free-flowing, so it's probably best to leave it that way. If you have it hooked up to automatically switch over like mine, you don't want to be running out the thing in the middle of the night to pull the cover off it when the power goes out. the machine also 'exercises' once per week to keep itself lubircated.

[Scott T Smith]

One thing that I have not seen suggested..... set it up so that your wife (or kids) can operate it if you're not available. Much better if you factor in airflow needs and install a door on the structure, with step by step start-up and shut-down instructions in a waterproof pouch on the inside of the door.

[Ray Newman]

Gents: I now live in the Pacific North Wet, AKA Washington State, but grew up in NY in 1950-60’s.

What I am wondering how hard is it to start these generators in the winter using a cord pull start. Or if a battery start, how do you keep the battery from freezing up or loosing power from the cold?

I remember “back in the day” as cold weather being a killer for batteries and trying to start up small engines. Has technology improved that much??….

[Anthony Whitesell]

17.5kW portable or 7.5kW portable?

[Anthony Whitesell]

To be more specific, I would drop some pieces of 2x4 down and one across (U shaped) to support the roofing from the bottom. In addition to supporting it from the bottom, this would allow you to get some pitch to it for drainage and for, your concern, move the roofing away from the joists. As it won't be bearing a snow load, you may get away with the fiberglass version if it's cheaper.

[Bruce Wrenn]

I would build a shed with removable sides. Roof remains in place. Be sure and get an electric start generator. Buy a HF float charger ($4.99 on sale) to keep battery topped off.

[Tom Fischer]

Anthony -
17.5K
http://www.generac.com/Portables/GP/Products/GP_17500E/
Yes, that's a good idea for supporting the roofing.

Ray - the unit is electric start, has a built in trickle charger.
The electrician is going to wire it in, so we will have a line installed for the trickle charger.
I have never used a block heater, but maybe a magnetic one will work. (aluminum block?)
The company says you can use 10W-30 oil in the winter.

Scott, thanks for the idea, but I am the maintenance crew. No backups.

[Joseph Tarantino]

Gents: I now live in the Pacific North Wet, AKA Washington State, but grew up in NY in 1950-60’s.

What I am wondering how hard is it to start these generators in the winter using a cord pull start. Or if a battery start, how do you keep the battery from freezing up or loosing power from the cold?

I remember “back in the day” as cold weather being a killer for batteries and trying to start up small engines. Has technology improved that much??….

most of the portable generators, and all of the standby generators, have trickle chargers that keep the battery charged so that when power is interrupted, the battery is ready to start the generator. my 4 KW portable is a pull start and always starts on pulls 2-5. but i maintain mine religiously and start it ( and run it) every 6 months.

[Anthony Whitesell]

You realize that you won't be able to pull all the running power the unit is capable of, right? 17,500 W /240 V = 72 A; the unit has a 50A outlet. That's one of the service centers complaints about portable generators being used to power houses. They just aren't built for it. I've been checking prices and location for a year or so, while I wait for there to be money in the bank account.

If you plugged into all the outlets on the power panel you could draw a total of 72A, but through the twist lock, you'll be limited to 50A or 12kW.

Personally I'm aiming for a 7.5kW/10kW unit with a 30A twist lock. (240V x 30A = 7.2kW)

[Tom Fischer]

Anthony, you have me there. I think the electrician said that he was going to connect a couple of the outlets, so that's probably 72A. He also said that everything in the house will run (not simultaneously), except for the emergency heat (2 each 60 amp breakers). The house is 400amp service, two main panels, maybe that is different from what you are thinking. I think one outlet goes to one panel, smaller outlet to the second panel, gets the total amperage. Don't know, is that it maybe?
But I have wood/coal furnace (120K BTUs) which is 95% of my heat need.
I went with the portable because
1) total cost (about 1/3 of price of a standby)
2) don't need permits for a machine on wheels.

The standby required building department PLUS Fire Inspector. The first was OK, but the Fire guy said I needed concrete filled steel posts in front of the propane tanks. Ya know, the industrial park look, same as a Burger King parking lot. He was flexible in that I could paint them any color I wanted. Personally, he was a nice guy, but just more government out of control. Last I checked, it is my property. Deal breaker for me, not doing that.

[Anthony Whitesell]

Techinically you have 144A of 120V service (72A on each leg). But you have to subtract double amperage for anything 240V. If you have a 100A main panel (100A of 240V service), you may be able to run everything. If you have 200A main you will only be able to run most stuff.

You should have asked how much to bury the tank. A friend of mine save a ton of money by burying his. Above ground required a minimum of 4 concrete post footers 10" diameter and 4' deep or a 6" thick pad 12" wider and longer than the base of the tank (no posts required). Burying it required a hole (don't recall the width and length), but had to be two feet deeper than the tank was tall. One foot under willed with gravel and covered in silt fence and the top of the tank could be no closer than 12" to the surface and no deeper than 24" from the surface. He dug the hole and gravelled it himself and dug the trench. The tank cost less to.

I wonder what the 'driver' was for the concrete posts. Was the tank in a particularily crash 'likely' area?

[Tom Fischer]

The tank was on the lawn, setbacks were OK, but only 15 feet from the driveway. However, I have a pretty large yard, so the tanks would have be 150 yards from the street, certainly not a danger to motorists not trespassing on my property. Unless it's the UPS and USPS delivery drivers who can't be trusted, the logic of the rule eludes me.
And not burying any tanks either. Most homes around here heat with oil. That's another problem. My homeowners recently sent an emphatic message that no homeowners policies will cover buried oil tanks that leak. Don't know if propane leaks, and no interest in finding out.
Life seemed simpler years ago.
Happy holidays.

[Anthony Whitesell]

Ditto around here. Burying an oil tank is way way expensive. They require a double walled tank in a sealed concrete vault with a leak detector in the double wall and one the in the vault. Then insurance MAY give you a policy. Propane is a gas when vented so if it does leak the ground may contain it for a while but once you disturb it, the propane will evaporate (unlike oil)

[Tom Fischer]

Old thread, thought I would update it.
The licensed electrician finally hooked the unit up.
Has two configurations for running.
I can run 50 amp(X 220v) or
50 amp(X 220v) plus 30 amp (X 220v) total 80 amp (X 220v).
The house service is 400 amp (two panels), so the single plug only backfeeds one panel, but connecting both plugs feeds both panels. Obviously can't run everything at once.
At 50 amp output I have pretty much everything available except heat pumps for air conditioning (2 each 2 ton)
With the 80 amp connection I can run one heat pump.
The house also has electric "emergency" heat (rarely use and cannot run on the generator - 2 breakers total - 60amp X 220v). I installed a 120K btu wood/coal furnace a few years ago. Just need small amount of electric for the blower. That heats the house.

The generator sits now in the basement. The large local builder (who uses generators all the time) said that is best.
If I store the generator in a tight confine (dedicated shed) the mice will probably get at it, in it, and chew the wires.
So, it stores in the heated basement, also solved the problem of cold dead batteries.
Also, the generac came from the factory with 2 wheels and a front "foot". Took that off right away, added a third caster (with a brake).

Thanks again for all the help.

[ray hampton]

There is no way that you solved the dead battery, if you fail to keep the battery charge, one day you will need the generator and find that the battery are dead with no way to charge it, I remove my lawn tractor battery and charge it every two weeks or start the tractor twice a month to keep the battery charge

[Richard Shaefer]

does your insurance company know that you have installed an internal combustion engine in your basement complete with fuel feed? You might want to be sure just incase they decide not to cover you if anything ever happens. for what it's worth, Iv'e had my generac outside in its enclosure for many years now and never had pest issues.

[Chris Damm]

You need a lot of ventilation or it will overheat. I left the gables open for my 5000 watt gen. and it shut down due to overheating in about an hour in 45° weather. Just put roof over it and leave the sides open!

[Matt McColley]

I've been brewing a similar plan for my generator (smaller unit) for some time...

My plan actually makes the dog house look like a dog house... and thus disguises the gnerator. Keep in mind that in Katrina, houses with generators were targeted for theft.... specifically to get the genrator.... so making it look like a dog house has "tactical" merit.

My plan has the end wall hinged to the platform at the bottom, so that it can unlatch and pull down to make a ramp (my unit is on wheels.... but if yours is not, you could get in there with forks or pallet jack to pull it out).

You need to plumb air in and exhaust out... and vent the gable to let the heat out... and if this is an air cooled generator, install a fan.

Think security.... air and exhaust flow.... and heat removal....

[Joseph Tarantino]

).......The generator sits now in the basement......

can you say " asphyxiate"!

[Tom Fischer]

Of course I don't run the generator in the basement.

As I said, ... So, it stores in the heated basement,

Meaning, the Generac sits in a row next to three lawn mowers of various sizes (the largest being a diesel), a troybuilt rototiller, 13 hp snowblower, and a few other small engines, two strokes and such. I never run any of these in the house. The big advantage of storing these in the house is that none of these machines ever get mouse nests in them. Plus, they are always dry. As opposed to my tractor shed, which also has some small engines, one Ag tractor, and a couple of three point hitch implements. And has mice everywhere, looking to set up shop in every nook and cranny.

Also, I gave up on the "dog house" storage idea, again, because if the mice get into the machine, ... just isn't worth taking a chance.
Maybe some of you folks don't live in rural areas. Just trust me, if there is a possibility that you will get mice in your machines, you want to try something else.

The electrician gave me two hookups, in the driveway, and under that deck
http://farm7.staticflickr.com/6046/6390661395_ed63240ae9_b.jpg
And I bought a boat winch to get the generator up the hill and under the deck. Works OK.

The reason I updated the post (after the licensed electrician had finished) was to inform that this 17.5KW (startup) Generac does put out a total of 80 amp @ 220v.
Been some other posts on output recently.

[Joseph Tarantino]

oops. posted in error.

[Van Huskey]

not being that far from where you are, tom, what led you to get a portable generator that big as opposed to a true standby? if you need a winch to move it into operating postiion, it's not exactly a lightweight unit. i mean, 80 amps! that would even handle my cental air during a summer power failure. as it is, since we have NG, i can run 1/2 the house easily on 20A. or are you primarily electric?

Your answer from post #16:

"I went with the portable because
1) total cost (about 1/3 of price of a standby)
2) don't need permits for a machine on wheels.

The standby required building department PLUS Fire Inspector. The first was OK, but the Fire guy said I needed concrete filled steel posts in front of the propane tanks. Ya know, the industrial park look, same as a Burger King parking lot. He was flexible in that I could paint them any color I wanted. Personally, he was a nice guy, but just more government out of control. Last I checked, it is my property. Deal breaker for me, not doing that."

[Tom Fischer]

Hi Joe,

No, we have no Natural Gas here. Maybe the terrain is too hilly, or too remote. But if we did have NatGas, probably would have bought the standby.
I have a neighbor with a 20Kw generac standby with Propane. It is nice, and very quiet.
Probably would have cost $12K with everything the Fire Marshall wanted. My neighbor says it costs about $100/day to run. Not cheap.
And then there is the not so small problem of what if I can't get a propane delivery during a power outage.
We are only a few miles from Interstate 80, so I figure that I should be able to buy 15 gallons of gasoline, no matter what happens.
So I went with the gasoline fired.

[george newbury]

<snip>
And then there is the not so small problem of what if I can't get a propane delivery during a power outage.
We are only a few miles from Interstate 80, so I figure that I should be able to buy 15 gallons of gasoline, no matter what happens.
So I went with the gasoline fired.
Been several threads over on the tractor forum about different generators etc. Several posters posted that during the recent East coast outages they had great trouble getting gas. Some stations were shut down, others had lines an hour long. You probably should buy 20 gallons of (preferably) non-ethanol gas, treat it with Stabil, and "cycle" it, pouring it into a gas burner every 6 months.

I've only got a 7KW generator with an 8 gallon tank at my house in Virginia. I use the tank as a "storage tank", draining fuel for my lawnmower, then refilling it and treating the refill with Stabil.

[Kevin Bourque]

The most important aspect of your generator house is the floor you use.

We parked one of our tractors in a pole barn with a concrete floor and the other tractor was in another barn with a gravel floor.
The tractor on the gravel floor had started to show signs of rust within months whereas the tractor on the concrete floor was rust free.

There was plenty of ventilation and the ceiling is about 9 feet high in the barn,
but the moisture in the ground permeated through the gravel floor causing the rust.

If you use concrete for the floor make sure it has a vapor barrier. If you use wood make sure its at least 8" off the finished grade.