Slightly O.T., portable generators

Looking at buying one soon, want everyones' advice.
Building a house this year, geo thermal heat, radiant floor, well, thinking a running 7K will be enough.
What do you think, self contained or PTO, have a Farmall M to power a PTO unit. From what I saw an M will handle up to about 13K in northern tool.
All replies appreciated, Thanks.
Adrian

Just make sure you have enough to run your well pump. Last ice storm,our power was off for 3 days. I ran a 12K with my Oliver 66 the whole time,so yes,the M would run a 13K.

My feeling is I don't want one more small engine setting around not getting used. I suppose a gas engine powered alternator is ok if you check/run it regularly(who does that?), or if you get a fancy unit that checks itself. I imagine your M starts when you want it to. I run my 15k constant/25k intermittent with an AC "C" (comparable to an IH "C"), and it does fine for the house and shop. If I need to get full output then something on the order of your M would be more appropriate.

A friend of mine recently built a home with geothermal heat pump HVAC. He has dual 200 amp service! That setup needs a lot of power; 7 KW might be on the light side if you expect to use it for backup heat.

I have geo-thermal. 7K would not begin to be enough. I need closer to 17K.

Best advice is to go installer and ask for operators manual or look at the tag on the unit you plan to buy. Then get familiar with how geo-thermal works to really get a handle on power requirements.

It takes alot of power to start the compressor. Also; if the system is cold you must start the compressor and second stage. The second stage is resistance heat. The solution is shut off the second stage until you get the compressor rolling and then turn on the second stage. Determine how to do this before you have to do it. My folks learned the hard way.

Remember too that geo-thermal will call for second stage when it is about 5F outside or if the system or house is cold after a storm you may have to run compressor and second stage. Power requirements will surprise a person.

Hope this helps.

John77046

I have a geothermal system and it is great, but the compressor requires a lot of power to start, just like any other compressor. Once running, it is very efficient.

One problem when powering a generator with a tractor is governor responce and stability. The letter series tractors did not have very stable governor. You may find a problem with stability, or holding speed when a load kicks in.

Thanks for the replies so far, I've been looking on the web and am now leaning towards 15-18K, the M will still handle this size. I am going to figure out how much load I want to supply and will have a wood stove for additional/emergency heat so I could get away without powering the geothermal.

Thanks, Adrian

Buy a small portable generator, keep a big wood pile, 2 years surplus, and forget trying to power the geothermal in an emergency.

gene

No 2nd stage resistance heaters on the geothermal systems I'm familiar with.
We buried enough pipework in enough trenches the system doesn't run out of capacity.
I agree entirely with your electrical advice.
I hope the backup power plans include a proper transfer switch.

As a generator tech let me tell you this. Check out the unit before you buy it. Make sure you will have a place to get parts or repairs when needed. I have seen people rush out and buy the cheap imports and then find out they cannot get parts. I have one in my shop. Man paid 300 for it. Has five hours on it needs repairs and cannot find parts.I have been looking for over six months.

Yeah, and I've had several American brand generators that were worse, in regard to getting parts. Especically the Colemans.

Some of these Chinese generators are less than half the price of the USA branded counterparts. I'll add also that some are very rugged. You just have to pick and choose. When you buy that cheap, future parts availability is not always a concern.

Lets not argue or any tat-for-tat but rather get some good information out to folks.

Buickddeere is right as to underground pipe, wells, etc would be matched to the compacity of the heat pump. The heat pump is designed to meet most situations.

In Minnesota/South Dakota, as other places, there are the extremes. Here geo-thermal units are installed with auxiliary heat source or secondary stage duct heaters to meet the extremes. My understanding is that installing a system to heat a house at the extemes (5F to -35F) would be cost prohibitive and therefore the need for auxilary heat source. It is cheaper to use auxilary heat for extremes than to purchase excess capacity.


A couple thoughts/situations.
-----
Your are caught in a storm away from home and power goes out. When you get home you hook-up your generator -- but the house is cold (say 55F) Your thermostats are hardwired into 110V and are programmed to maintain the house at 68F. The generator starts and thermostats call for geo thermal heat plus auxiliary backup. Remember the thermostat is trying to raise house to 68F ASAP. Calculate the watts needed at this point as this is surge(?) -- remember system is efficient when up and operating. This also assumes you turned off your refregerator, deep freezer, etc.

Thinking outloud could this problem be solved if a person puts batteries in thermostat so a person can lower thermostat to house temperature (ie. 55F) --- get tractor/generator to 540 and then slowly raise thermostat only engaging geo thermal and not aux heat? I have swicthes on geo thermal unit to turn off aux heat.

Regardless, I worked with electician to "do the math" ahead of time. 17K in my house must be managed manually with switches.
---------

Mistake I made recently that cost me real $$$. I was lowering my thermostat 6F at night while family slept. I was first-up in the morning and would "crank up the heat" 6F degrees so everyone would be happy. My thermostat was set to call for auxiliary heat if the temperature difference was greater than 2F. I was heating the house in the morning with the more exspensive aux heat source. Kinda defeated the whole purpose of turning the heat down while family was "undercovers". I have since read the thermostat manual and dicovered that I can set the thermostat to call for aux heat ir the difference is more than 6F degrees. Result, it takes longer for me to heat the house in morning but I am using the more economical geo thermal to do it.
----------

As I said, I am not fighting with anyone. Prove me wrong and it saves me $$$.

John77046

No, a 7K isn't enough unless all you want to run is a couple of lights and a few outlets. Find out what the power requirements are for what you "need" to run. For me that includes the well(pump)the heater (I also have geothermal), the refrigerator, freezer, lift pump for my septic/leach field and a few lights. It's somewhere around 15-17K according to my HVAC guy. I haven't verified that, but an 8K isn't enough. I know because I have an 8K from my [previous house (just moved here 2 months ago) and it won't power all the above. Personally, I'm upgrading to a propane unit. It's less maintenance than gas and I can hook it up directly to my propane tank that is only used otherwise for a fireplace. A PTO generator eliminates the motor to run it, but what if you need your tractor while the power is out, like if there's snow to remove or something? If that's not a problem the Pto is a viable choice.

There's 2d stage resistance on my geothermal because I have a switch to turn it off when I'm on generator. I also know because I used the resistance heating the first 6 weeks or so it operated (during construction) before the "geothermal" part was even hooked up. It wasn't cheap

Another couple thoughts on generators.

-----------
I keep a small portable generator around besides the tractor PTO generator. Actually small generator is in basement so warm in winter. The small generator is used to run Knipco (torpedo heater) to warm tractor engine(s). Also used to run battery chargers, engine block heaters, car block heaters, etc. I have a plastic tub to slide it around in snow and ice. Headache is keeping fuel fresh in it etc. so it will run when needed. I also keep a long 10 gauge cord so I can run items in house such as refrigerator, freezer etc individually.

I know it is overkill but with small children in house, price of food in freezer, missing a day of work because car won't start, disposition of wife it is just better way to go in my case.
----

Also; If running a tractor PTO generator becareful of sucking the tractor full of snow/sleet during a blizzard. If everthing works your filter(s) will be plug with snow/ice. If filter(s) fails not so good. Some folks around here run tractor PTO generator inside an outbuilding because of this. They all have different schemes to vent exhaust and getting fresh air into building.
---------

Often times main concern is not heating house but pumping water for livestock, thawing out water tanks, milking, etc so livestock doesn't doesn't suffer --- then house is heated.

--------

Everyone's situation / goals are different. As one fellow told me, "we all view the world from our own particular vantage point."

Hope this helps.

John77046

I was wondering why people would undersize the system's underground pipework? It defeats the whole idea of geo thermal.
Certainly an air to air system in the south where freezing temps are not the norm. Then certainly resistance aux heaters for operation for those times below 35F or so. Are the more economical solution.

Lets put it this way... a 25KVA generator will produce 100 amps. A 50 KVA will produce 200 amps.
You stick a current clamp on a leg going into your breaker panel and see what it's drawing with all your essential stuff running AND when it's STARTING the pumps. I'd be willing to bet it's going to be 75+ amps. A 4 horse compressor can draw upwards of 60 amps just to start...
We've got one of those silly chink generators for the house. It's rated at 5500 W I think. Anyway, it makes 20 amps. It's not enough by a long shot. That's with a couple of freezers, a few lights (compact floruscent), a 1/2 horse pump, and probably a 1/4 horse furnace blower motor. If any one of those things cuts in while another is running, it's game over...
I'd not even consider anything less than 10000W for a house like this with light electrical loads, and that's just for the basics.

Another way to look at this. You could buy a 15 KVA and be sure of running it with your tractor but mabey not have enough generator or you could buy a 25 KVA and probably have enough. IT might be too much for the tractor to sustain on a steady basis but it could probably start some of those pumps fairly easily, and they do lighten up once they're running...
We also have a 25 KVA for the farm and run it on a 45 hp tractor OK when needed. It's light, but it handles it OK.

Rod