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Posted: 7/5/2012 4:54:54 PM EDT
I am looking to step up in backup power.  I've got summertime covered with 7-8kw, 7k will just barely run the a/c.

My concern is wintertime.  My home is total electric.  My heat pump/furnace has two auxiliary heating elements for below freezing (I assume that's what they're for)

Each element has it's own 50A breaker on the front of the furnace, and I think they're rated at 40A each.

The furnace has two 60A breakers in my breaker box, nd the heat pump is on a 30A breaker.



Is there any chance a large portable generator will power my furnace?

I'm looking at a 15-17.5k genny if it's doable.
Link Posted: 7/5/2012 4:56:34 PM EDT
[#1]
Couple snaps of the label on the front of my unit...



Link Posted: 7/5/2012 5:00:25 PM EDT
[#2]
sure its do able. http://www.peakpowertools.com/Portable-Generator-Guardian-15-kW-Electric-Start-p/ggn4582.htm



gas hog!!!



how about putting in a wood burning unit, like a buck stove.  for the same price as that genny you can have it and use it pretty much for free.
Link Posted: 7/5/2012 5:22:00 PM EDT
[#3]
I have a stove in my basement.  I have had it glowing red and it was still 40 degrees upstairs

I was looking at a Generac gp17000e
Like this one
Link Posted: 7/5/2012 5:36:32 PM EDT
[#4]
Winter time is the time I'm most comfortable with.  I've got a Mr. Buddy indoor rated propane heater.  I'll just use that to keep one room nice and toasty and not have to run the generator.
Link Posted: 7/5/2012 6:12:44 PM EDT
[#5]
What ever you figure out you need add 50%. And go with diesel or propane, storing large amounts of gas sucks
Link Posted: 7/5/2012 6:36:10 PM EDT
[#6]
I dont want to add a propane tank but I'm always burning gasoline.  I dont think gas will ever go bad around my house
Link Posted: 7/5/2012 7:30:21 PM EDT
[#7]
That is a huge amount of current to be supplying with a generator, and would need a huge supply of fuel for any reasonable amount of run time. Also consider that a generator to comfortably supply that load with a cushion for other loads, is going to be very expensive.

Posted Via AR15.Com Mobile
Link Posted: 7/5/2012 7:51:36 PM EDT
[#8]
Quoted:
What ever you figure out you need add 50%. And go with diesel or propane, storing large amounts of gas sucks


Just curious, but if a generator can last, say, 5 hours on a tank of gas, how long could it last on a cylinder of propane (the kind I have for my grill)?

Rough estimates are fine here...
Link Posted: 7/5/2012 7:59:39 PM EDT
[#9]
Quoted:
Quoted:
What ever you figure out you need add 50%. And go with diesel or propane, storing large amounts of gas sucks


Just curious, but if a generator can last, say, 5 hours on a tank of gas, how long could it last on a cylinder of propane (the kind I have for my grill)?

Rough estimates are fine here...



Propane has abt 90,000 BTU per gallon.

Gasoline abt 140,000 BTU per gallon.

Roughly.

A 20 propane take filled w/ 18 pounds of propane has about 4 gallons of 90,000 BTU per gallon fuel.

So that's roughly abt 2 2/3 gallons of gasoline equivalent in a 20# propane tank w/out doing the calculations.





Link Posted: 7/5/2012 8:15:49 PM EDT
[#10]
Darn. I was hoping that I could store propane for my grill and generator instead of gasoline.
Link Posted: 7/5/2012 8:34:01 PM EDT
[#11]
Quoted:
Darn. I was hoping that I could store propane for my grill and generator instead of gasoline.



You can.

20# [~3.5 gallon] propane tanks are abt $30 each. 100# tanks [about 20 gallons] are about $100 if you shop carefully.

Considering 4 MFC with shipping cost ~$100 ––-and the essentially 'infinite' storage life of propane vs gasoline [that is much longer than most have a clue when kept in a sealed container]...

...propane isn't such a bad option after all...

...as long as PORTABILITY isn't a consideration.



It just gets better with bigger propane tanks. No one is running off w/ them in the middle of the night.



Link Posted: 7/6/2012 7:01:57 AM EDT
[#12]
If you have a stove in the basement, you need to provide a way to get that heat upstairs.  Are you leaving the door to the basement open?  It isn't the better solution but it works.

Is your air handler in the basement? If so, you need only to cut a fairly large square hole in the return air ductwork, cover it with a screwed on panel, and turn the fan switch from AUTO to ON.  The open return air duct will draw the heated air and the fan will push it throughout the house.  Simply turn the heat selector on the thermostat to the OFF position.  The fan will use about 600 watts if that.

I have done much the same here.  I have a coal stove in the basement and without using the indoor unit, it will hit 90 plus in the basement if I let run wide open.  By using the air handler, it will drop to less than 80 while the rest of the house is comfortable.  

Heat does no good if you can't get it moving.  IM me if you have further Q's.

I used to be an HVAC guy..

Ops
Link Posted: 7/6/2012 8:12:16 AM EDT
[#13]
Maybe a pelllet stove on the first floor, alot if them can be stubed out an outside wall for
a simple instlation.
Link Posted: 7/6/2012 8:37:05 AM EDT
[#14]
Link Posted: 7/6/2012 8:53:07 AM EDT
[#15]
Pix when it happens...

Link Posted: 7/6/2012 9:02:37 AM EDT
[#16]
Quoted:
Quoted:
I have a stove in my basement.  I have had it glowing red and it was still 40 degrees upstairs
I was looking at a Generac gp17000e
Like this one


Sounds like you need some vents in the floor with some fans to push the hot up faster.


This.  My friends house was this way.  Wood stove downstairs and just passive vents (i.e., holes in the floor w/ a vent grate on 'em) above the stove.  You could literally feel the heat rising through the vents.  They install a small ceiling fan and set to reverse, it did well to pull heat up.


As far as sizing your genny, I'm not expert - so somebody correct me if I'm wrong, please, but this is what I've learned from arfcom:  amps x volts = watts, so 80 x 230 = 18,400.  That's a hell of a genset, especially if you plan for the extra startup wattage or plan to run anything else.  IMO, best to figure out how to get the heat upstairs or get some buddy propane space heaters.
Link Posted: 7/6/2012 9:06:08 AM EDT
[#17]
Link Posted: 7/6/2012 9:09:45 AM EDT
[#18]
Quoted:
Quoted:
Quoted:
Quoted:
I have a stove in my basement.  I have had it glowing red and it was still 40 degrees upstairs
I was looking at a Generac gp17000e
Like this one


Sounds like you need some vents in the floor with some fans to push the hot up faster.


This.  My friends house was this way.  Wood stove downstairs and just passive vents (i.e., holes in the floor w/ a vent grate on 'em) above the stove.  You could literally feel the heat rising through the vents.  They install a small ceiling fan and set to reverse, it did well to pull heat up.

.


My friends went a different route - they put small fans in the vents.  They looked like PC fans (though this was early 80s).

IIRC, you can buy booster fans that go in the vents just for this very purpose, now.  Oddly, the friend I referred to was from back in the 80s.  Smart home, I believe, sells the in-vent fans.

I think the in vent fan is the best way to go.
Link Posted: 7/6/2012 9:13:37 AM EDT
[#19]
Why not leave the basement door open and set a fan in it???

Blowing down of course.




Link Posted: 7/6/2012 9:19:11 AM EDT
[#20]
Quoted:
My concern is wintertime.  My home is total electric.  My heat pump/furnace has two auxiliary heating elements for below freezing (I assume that's what they're for)

Each element has it's own 50A breaker on the front of the furnace, and I think they're rated at 40A each.

The furnace has two 60A breakers in my breaker box, nd the heat pump is on a 30A breaker.

Is there any chance a large portable generator will power my furnace?

I'm looking at a 15-17.5k genny if it's doable.


It looks like you would need 20 kw just for the heat.  You'd need 23-25 kw to run other stuff in the house like the refrig and some lights etc.

You might want to think about an alternative heat source like a wood or pellet stove.  Probably cheaper than a 25 kw generator.  And that will save you money down the road since it will have to be cheaper to heat your house with wood or pellets than with electricity.  

Link Posted: 7/6/2012 11:15:38 AM EDT
[#21]
If you really NEED 25 Kilowatts for back-up power, It may be cheaper in the long run to build a small guest house,
with lower energy  demands.... And live in it.
Link Posted: 7/6/2012 12:30:12 PM EDT
[#22]
Quoted:
I have a stove in my basement.  I have had it glowing red and it was still 40 degrees upstairs

I was looking at a Generac gp17000e
Like this one


that genset would only power your heat, barely. How efficient do you think it will be at full throttle?

You are going to be burning LOTS of gas.

I would certainly try to make something work out with that wood stove.

EDITED: because i just did some math
If you heater runs constantly, which I know it will not....You will burn about 75 gallons of gas a day.
Link Posted: 7/6/2012 12:35:49 PM EDT
[#23]
You loose a lot of energy as heat from the gas engine on the generator.

Better off burning wood or propane. I have a little propane heater that runs off a 20lb bottle for supplemental/emergency heat. Works pretty good. Keeps the main room of my house warm. I put it in the bathroom once, heat nearly drove me out of there.
Link Posted: 7/6/2012 12:48:14 PM EDT
[#24]
If you don't use Ops's advice above... Pick a room or two, and use those only during a issue.

I cannot run the A/C here on Gen power, but I've thought about using just a window-shaker to cool 1 room, and letting the others go to ambient.  MUCH less gas.  Only reason I haven't done it is I don't have enough genset power to run both the fridge and the A/C.  I'm considering buying a 2000W genny to dedicate to the A/C.  That way I have the 'right sized' unit (that's running most efficiently) to run the stuff that I run now, and a 'right sized' unit to run the A/C.

Alternatively, I could switch them on and off intermittently.  I ALMOST did this the last outage we had here, but decided it wasn't quite hot enough to mess around with.
Link Posted: 7/6/2012 12:53:19 PM EDT
[#25]



Quoted:


I have a stove in my basement.  I have had it glowing red and it was still 40 degrees upstairs





How many sq ft is your house, and how many stories?



How long did you let the woodstove burn?  We heat primarily w/ wood, but we have a small house.  Once we light the stove, it rarely goes out –– this is because of the recovery time.  Once it cools off upstairs (stove in basement, single story house), it can take 1/2 a day or more to warm it back up...



I think you're going to need a big generator, not a portable.  100A @ 240V is 24KW, and you'll need some headroom, and probably want to run more than just your heat, so maybe a 35KW unit.  Anything that size or bigger probably should be a diesel for efficiency's sake.  Once you add in all of the wiring, transfer switches, etc, you're going to be into this for a lot of money.



It may be cheaper to get a propane furnace that can run off a 20A 120V breaker.  It'll save you some $ on your electric bill too...





 
Link Posted: 7/6/2012 1:00:30 PM EDT
[#26]

My 10k will power fridge, freezer, a couple lights and a 5000 btu ac window unit. It burn about 20 gal of gas in 24 hrs doing it.A 25k diesel would power my whole house.we routinely power multible trailer houses on well sites with a 45k
Link Posted: 7/6/2012 2:15:50 PM EDT
[#27]
Quoted:
Quoted:
Quoted:
What ever you figure out you need add 50%. And go with diesel or propane, storing large amounts of gas sucks


Just curious, but if a generator can last, say, 5 hours on a tank of gas, how long could it last on a cylinder of propane (the kind I have for my grill)?

Rough estimates are fine here...



Propane has abt 90,000 BTU per gallon.

Gasoline abt 140,000 BTU per gallon.

Roughly.

A 20 propane take filled w/ 18 pounds of propane has about 4 gallons of 90,000 BTU per gallon fuel.

So that's roughly abt 2 2/3 gallons of gasoline equivalent in a 20# propane tank w/out doing the calculations.








You're going to need a bigger gen set than 15kw. I'm thinking at least 25kw if not closer to 30kw. You don't want to be running that thing at 100% capacity for very long.


EXPY37 is right about these figures, so why don't we look at them a little closer.

Engines waste 2/3 of the fuel they burn. Basically, only 1/3 of the fuel burned is used in creating mechanical motion, 1/3 goes out the exhaust, and 1/3 is lost to the cooling system.

What if you were to forget trying to power up that massive 220vac/100amp monster heater, and instead bought a smaller gen set and tried to recoup the waste going out your exhaust and cooling system to heat your home, or help heat your home?

If you burn one gallon of fuel an hour and created 114,000 BTU's, and you could use the waste just in the cooling system, you would have a 38,000 BTU's heater in your home. Since one watt is equal to 3.4 BTU's you are saving around 11,000 watts of power that a gen set would need to create.

If you were to mount a radiator with quick connects inside your home, and put an electric floor fan behind it, now it is just like having a huge heater core in your home. This is what they do in cars to heat them in the winter time. The quick disconnects are so you can use the gen set in the summer time to run the AC and cool your house. Just mount the radiator outside.

Now if you use one of those chimney heat exchangers in the exhaust, you could recoup even more wasted heat.

The money you save from not buying a bigger gen set would make these two projects easy to afford. You're still going to need a good size gen set from the sound of it, so that means a liquid cooled engine. You will be saving on fuel as well because you're not burning as much to make huge amounts of electricity, but I still think you may be close to a gallon an hour by the sound of things.


I'm not sure what your AC needs are, but here there's no getting around it, you need electricity. Your AC is only lowering the temp of your home say 20 degrees, but your heater maybe trying to raise the temp as much as 80 to 100 degrees from the outside temp so heating demands are much larger.

AC units this big are not rated in BTU's, they're rated in TONS. The ton rating is actually pretty simple. When AC was first invented, it was never designed for cooling a home, it was made to make ice. Since ice is sold by the pound, people who sold ice wanted to know how much water it could freeze in a 24 hour period, and the TON rating was born. If a unit was 5 ton, then it made 5 tons of ice in 24 hours, or froze about 1250 gallons of water every 24 hours. One ton of water in about 250 gallons.

Just for ease of numbers, there's 12,000 BTU's per ton of AC, or about 3,530 watts, so you can do the math to size your gen set.




Link Posted: 7/6/2012 4:54:22 PM EDT
[#28]
Okay, running the furnace with that set was a stretch, I just thought...   A 30kw propane powered standby unit I just could get for ~$9600.  But then i would also have to puchase propane and a tank for it.

I think I might be able to do something with the wood stove, maybe build a hot box around it and plumb it into a return....

Still, I think that 17kwset set for ~$2700it would be more than enough to power whatever I just want, and may not be a bad investment in and of itself.
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