I looking at an alternative to a large natural gas generator and looking at
a 5 - 7kW gasoline powered job with gen-tran manual transfer switch.
If its raining I can't use the generator outside. Our outages usually occur
during approaching thunderstorms or hurricanes so running the generator
outside is not possible.
I'm considering putting it in my detached garage which is about 30ft from
the house and has the fusebox. The garage is 21 x 25 two car garage.
I'm looking at installing a 20"x20" auto shutter gable vent and placing it
behind the generator with a gable fan blowing outward. The exhaust will be
plumbed outside through a thimble and the garage door will be up an inch or
so to let air in. (~400sqin area) in addition to my soffet vents.
CO detectors will be installed in the garage in case of a build up of co.
do you guys think that setup will work and be safe?
I'm not a big fan of gasoline generators, especially if you have power
failures often and for extended periods of time. Having said that, I have a
similar situation to yours. My detached 20x24 garage is 25 feet from my
house, in the rear corner of the garage, I built a platform on which I
mounted my 6.5kw Onan /Cummins gasoline generator. I cut a panel 18"x18" out
of the siding and installed a sliding panel. With the panel removed, the
generator exhausts out the opening. I run it with the garage door closed so,
from the house I can't hear it at all. My machine has an extended run tank
on it, so it will run through the night or around 12 hours, it ventilates
fine and when I turn it off, I keep the garage door open for a few hours to
exhaust any residual fumes
I'm looking at the Onan 6500 unit at Costco. Not a bad price for the
electric start included. that makes it easy for the wife to start it if I'm
at work. How much fuel does yours burn in an hour?
How is the reliability?
What makes you not a big fas of gasoline generators?
hastle of rotating gasoline?
Hassle of filling it and running it every month or so?
Frequent oil changes?
I wouldnt say we'd use it frequently. maybe 2 - 3 times a year.
We were on the far west side Rita and power was lost for a day or so. Most
outages are trees down on the power line and can take several house to fix.
Thats a LONG time without A/C in Houston. I have a roll around 10K BTU unit
cool one room since the central air wont work.
I don't know the model they have at Costco, mine has both a pull starter and
an electric start, but in January, when its 10 degrees out, I don't want to
be pulling a 14 HP engine. The gasoline issue is the big pain. You have to
dump it out of the machine a couple of times a year, as well as store a
decent quantity in containers for an emergency. I've had my machine for
around 9 years and it is reliable. The fuel consumption depends on how hard
it's working, but generally a little less than one gallon per hour
I agree in general, but I'm not sure I would use a plastic dog house.
If you fill up your plastic gas can at a filling station and put the
can on the plastic/vinyl liner of your pickup, you can get a big enough
spark from static to pretty much set yourself on fire. Granted, your
generator should be grounded, etc., etc., and it's probably perfectly
safe; but I'm still not sure I would risk using plastic because of the
risk of static. Also, spilled gas might do something to the plastic.
But a wooden dog house (or its equivelent) would work fine.
I'm looking for something I could make semi-permanant and this setup would
do the trick. My outages aren't what I'd call frequent at about 2 - 3 times
a year but we now have a baby girl and the last outage was 8 hours and it
got HOT in the house. Baby was crying and mama was falling apart. I have a
portable A/C that can be rolled out and hooked up to cool a single room and
vent the heat outside or to to bathroom (exhaust vent on) if the windows are
This is in Houston, TX as a point of reference for heat.
I'm trying to make it somewhat simple with the gasoline generator but that
natural gas generator sure is nice. $8K to get one installed is a bit steep
Gee with that many watts check the fuel necessary for 12 hour run, its
likely 75 or a 100 gallons.
How will your family feel about having that many gallons stoired around
if a hurricane hits power will be out for a week or longer, your
generator will die when your fuel supply quits.....
I doubt keeping a thousand gallon tank is permissable in a resenditial
neighborhood, let alone affording thew tank plumbing and monitoring
Now add in keeping your fuel fresh:(
Just buying stabilizer will cost a lot.\\
have you priced a natural gas generator at home depot? around here 5
grand can get you operational, and natural gas is tops for reability..
This is why they have diesel generators. No safety issues storing
several hundred gallons of diesel, enough to run for weeks. With some
diesel Sta-Bil it will store just fine for at least a year.
First, these things throw off a huge amount of waste heat, and you can't
enclose them *in the least* without raising the temperature
significantly. You have to understand that those cheap generators are
hardly avoiding the boiling point on the fuel tank as it is. I mean
that literally: a little bit of stagnant air around these things can set
the gasoline aboil. They have to be operated in the open air for the
sake of convective cooling. You can hardly put them next to an exterior
wall without them getting overheated. The hotter your fuel tank is, the
more likely it is to catch fire.
Second, what you propose is a serious building code violation and fire
code violation on several accounts. Gasoline storage indoors, running
an engine indoors, plumbing fiery exhaust through a wall, hard-wired
electrical connections from a non-compliant installation, etc. It will
surely void your house insurance if you have that. It will be very
obvious to your neighbors what is going on, and this is the sort of
hazard that would motivate a report to the authorities by someone who
might overlook more benign offenses.
Third, you are dealing with over 10 horsepower in rotating machinery and
electrical circuitry. This is a huge monster compared to any appliances
or tools most homeowners are used to. It requires a different regime of
care and construction in how it is used. This is not a kitchen gadget
that will just blow a fuse if something goes wrong. Your habits and
intuitions are likely not suitable. You have to admit that and learn to
treat these machines with respect and utmost caution. This can be hard
because they are so cheaply made and invite contempt instead of respect
in their manufacture. But you have to respect the hazards inherent in
that much power.
I think you can justify some high-risk improvisations during a hurricane
and its aftermath, if one is vigilant. I've been through four of them.
I've seen the idiot shoppers in Home Depot after a hurricane asking a
minimum-wage clerk how to wire a suicide cord to light up their house
with a $500 generator.
For you to permanently install a portable generator this way is not
prudent. I suggest you consider a small concrete pad outside the
garage, with a plywood weather box that you can lift off and set aside
while you run the generator, with a plug-in cord. Maintaing portability
saves you the code issues, and outside of the structure you have a much
reduced risk of disaster.
I'll second what Richard said. You're dealing with powerful forces.
Electrical and building codes have a lot of seemingly unnecessary silly
redundancy built into them for a reason. Every one of those foolish
regulations is there because someone died. It is possible to take a lot of
shortcuts and still feel confident that if you do everything properly,
nothing can go wrong, and when the power comes back on, you can disconnect
the generator so there was no evidence that it was ever there, so you're in
compliance with all the codes. But there's a lot of risk in those if's.
I decided it was time for a generator after the April Fool snowstorm of 1997
in the Northeast took out my power for three days. I started out with the
assumption that I could get a decent generator at Costco and do all the work
myself, but after I did my homework, I ended up hiring a contractor who
specializes in generator installation and had a 9 KW propane unit installed.
I had the propane company install a couple hundred-gallon tanks, and a
plumber install the piping (and get the necessary permits). I chose a manual
over an automatic start for two reasons. First, during a thunderstorm, I
don't want the generator connected to the house wiring, where it would be
just asking to get nailed. Second, in a catastrophic event like a tornado,
where the house is severely damaged and wires are hanging down, I don't want
power running through them. The tractor batteries they use on these don't
last very long, and when you have to go out to start it yourself, you become
more aware of when the battery is starting to weaken. You also know when
it's been running so you can track the number of hours and know when it's
time to change the oil.
Consider the following:
How much is enough power? Central air is probably a luxury, but a portable
unit is not. What about the refrigerator(s)? How about hot water heater? Do
you want to do laundry? Do you want to end up like Oliver and Lisa Douglas,
always having to figure out what you have to turn off to turn something else
on? With 9 KW, I can run anything I want in the house except the central
air. This includes two refrigerators, dehumidifier, washer, gas dryer, water
pump, two furnaces (oil-fired but with big blowers).
How much is enough fuel? I have a five-gallon gas can for the snowblower,
which gets me through an entire winter, and that's a major hassle - keeping
it fresh, making sure I have enough, keeping it in a safe place. I wouldn't
want to deal with the quantities you'd need to run a generator for a few
days. My 200 gallons of propane could get me through two weeks of steady
use. If an outage goes beyond two weeks, I probably could call for another
propane delivery but if something caused the power to go off that long, then
most likely the propane company wouldn't be in operation. But then, for a
disaster of that magnitude, probably the National Guard would have ordered
me to leave my home by then anyway.
Are you and your wife willing to go out in the weather to start a
manual-start unit? This was one inconvenience I was willing to endure for
the reasons listed above. My wife still thinks the procedure for starting it
is more inconvenient than sitting in the dark, but now my son is old enough
to do the job, so that helps.
If you really want a cheap solution that gives you some emergency power,
then I'd say to get a portable unit at Costco and some very heavy gauge
extension cords. If you want something that lets you live a somewhat normal
life (without central air), then call a pro to install a propane unit. If
you want something in-between, then think about it some more and you'll
probably end up with one of these two solutions.
Oh, and by the way, life won't be completely normal. If you have cable modem
and/or cable TV and the cable network survives the storm, it will be running
on backup batteries and probably will fail within 12 hours. POTS and DSL
might last longer if you have a direct connection to the central office. If
you have any UPSs, they'll probably get upset over the low-quality power and
keep switching on and off and beeping a lot. The cheapest and the more
expensive UPSs usually can be set to low sensitivity and run OK. But the
ones in between will keep switching on and off until they die. A heavy
inductive load like a small air conditioner or a dehumidifier will help
stabilize the power.
If you read the original post I'm NOT considering a suicide cords and
instead buying a proper manual 6 circuit transfer switch and having it
installed PORPERLY. We don't run propane here only natural gas but the gas
is plumbed on the other side of the house and already has a max load of 200
SCFH (250SCFH meter) so I can't hook a hungry 100 SCFH generator to it
without dropping the gas pressre.
The generator in my situation would have forced convection by the sucking
action of the gable vent fan right next to it. It would pull fresh garage
air across the motor to the outside.
Gasoline is stored on the opposite side of the garage and I don't expect any
appreciable rise in temperature on that side of the garage.
Damn, I never realized a generator was such a dangerous machine, imagine
what damage you could do with a car. These things do generate lots of heat,
which is why you want to provide a substantial method for ventilating it. I
also use fireboard on the walls surrounding the machine. I'm sure all
generator manufacturers have specific warnings about using them indoors,
which is not exactly what you plan to do, but they need to cover themselves.
As a side comment we have satellite TV. During a severe storm there mau
be a outage, in rains so heavy you would pull off if driving. as soon
as the main storm passes our satellite tv comes right back up. We have
DVRs similiar toTIVO so during a outage we have in stock programming to
Back on the generator, 9KW probably is too big to support fuel wise.
I have 3 generatrs all portable the small 2500 watt gets the most
uses less fuel, somewhat quieter, and lightweight for easy
CHECK THE FUEL CONSUMPTION of a 9KW its a lot...
since gas stations depend on electric getting more fuel in a TRUE
emergency, when you need it the most will be a big problem.
another issue, although a permanent natural gas generator costs more
its a asset to your home that will increase its value. a work around
scheme will only cause hassles at home resale time.... perhaps decrease
The key is choosing the right size generator. remember this doesnt
so you need continious power for a window unit, fridge, small tv, a few
you DONT need to run every electrical device like it was a normal day.
you switch the different circuits as needed.
if you downsize your 9KW plan, your natrural gas meter is now large
enough, with a automatic transfer switch your wife has to do nothing to
start it, important loads will automatically come up during a outage.
she can make other decisions as needed.
what natural gas uses in your home? furnace? hot water tank? pool
heater? in a emergency turn off pool heat! such type decisions help one
get by when others are really stuck.
A permanent install natural gas unit increases your homes value! while
ooffereing much for you while you own it...
Still a bad idea.
What if the exhaust fan fails? What if the shutter is frozen shut in an ice
storm? Even though the gas is stored outside, it is still used inside and
has to be poured into a tank. Gasoline inside a house is a danger under any
circumstances, especially since you have natural gas appliance. Ask my
brother about that.
As for the NG, will you be running full load with a generator? My guess is
that you will want heat and hot water, but not run a dryer. You can
probably keep the load down with little effort if you must run the
Probably easier to put a proper outdoor auto generator by or near his
natural gas service and run a underground cable to the garage.
since his service entrance iss apparently at the garage he could but
the transfer switch there like it belongs.
the OP should realize if he ignores codes and does what he plans
putting generator inside detached garage and has a fire from either
generator operation or having lots of gasoline around his homeowners
may disown him if theres a fire.
besides in a time of emergency when the generator is most needed the
fire department response time will likely be slower...
I am chgecking on large generator gasoline fuel consumption...and the
installed cost of natural gas auto power systems its dropped a lot
recenlly probably because production is up what with unreliable power
grids and natural disasters
Well I stanbd corrected about fuel requirements for LARGE generators...
My small ones are fuel piggies, large 7000 watt ones average about 3
gallons per hour at full load about half that at half load and below.
so a 24 hour interruption could require 75 gallons or so at full load
about half that at half load, note quarter load doesnt change fuel
requirements much, kinda idiling requirements.
noted some larger portables are triple fuel gasoline propane and
natural gas ready, although gaseous fuel derate generator power by as
much as a third.
on gasoline stations with generators during a emergency once the tank
is empty, new tanker deliveries will likely be disrupted.
kinda sad to have spent several grand for generator and transfer switch
only to run out of gasoline.
note you can avoid the transfer switch altogether, by some main panels
have special breakers for the generator that CANT be turned on unless
the power line main is OFF, these are NEC approved and safe.
If the OP is destined to go this route I would put in a natural gas
quick disconnect and a shelter on the side of his home, with a
underground wire to his main panel or transfer switch.
or roll the gasoline generator to his garage door and leave it open
in any case he should spend a little extra for a dual fuel generator,
once a long outage occurs he then has the CHOICE of providing natural
gas service to his generator
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