Most Efficient Use of Generator?

I'll do that if you are willing to stay in the house an monitor the situation!

Well, can you get Casper to accompany me and do you stock bud on your fridge?

Get a controller to have the gen set come on as heat is needed.

That would work if the genset had an electric start...it's a pull start so that would involve a bit more than I'm willing to do.

What would happen if you drained the water heater and all water lines, and just let the place get cold?

Then everything freezes and expands and wrecks the house! Been there done that! Before I finished the renovations, I did just that. Now that there are new floors, walls, etc. I don't want them to buckle and crack. It also costs more to have the system drained, and restarted than it does in fuel to keep it just warm enough.

Is the FHW system a closed loop with recirculation?

If so; have you considered using the RV safety rated anti-freeze instead of water?

If possible to do so your system freeze issues go away.

Also; If the heating loop is not isolated from the drinking water system, your local code will most likely require a "double-wall" heat exchanger be installed.

I would think running back and forth to start and shutoff the generator would become very time consuming as well as frustrating.

I see no real way of determining which of your two methods would be the most energy efficient other than to run in both modes at the same outside ambient temperature and weather conditions for the same period of time, log the results and do a comparison analysis.

Let it run all the time. Get a remote temp sending unit. Chep weather stations have this feature.

Letting.the house cycle leaves too much to chance.

It might be possible, if you have enough engine after de-rating, to convert genset to propane or natural gas. This would alleviate the 5 gallon limit at least.

I not only agree, I have had conversations with people who have propane, changed the fuel to propane without any problems.

OK thanks for all the input. I think I'll just keep it at 40+ degs and run the genset continuously, watching the fuel level periodically.

Just FYI - the house is well insulated and has good storm windows. It's located right next door so checking is not a big deal.

The main house is much simpler...big azz genset that runs the whole damn house!

Just hoping I don't need either genset for an extended period this winter!

Thanks again.

How do you heat the main house?

I'm thinking that if it's forced air, you could just run a single flexible duct over to the guest house, or even insulated PVC.

I'm going for easiest and least amount of money to keep it above freezing.

Main house is FWH too..."next door" is 1/4 mile! " :-)

If it was me and the genset had a low oil shutdown system I would just refit it to run off of a larger fuel tank.

If you really wanted to get fancy you could buy a simple mechanical three way fuel valve from the local automotive parts store so you can use either the local on unit tank or a remote input line and you're good to go!

I've been thinking about doing just this. Maybe even rigging a quick disconnect fuel line to go from my truck, which has a 36gal tank, to the genset. That would be a safe tank, and could run for a very long time.

I agree with post#10

.Keep the heat just hot enough to prevent freezing.

The generator will unload when the heat unit turns off,even though it will sound almost

the same,if the unit is frequency regulated.

The most efficient generators use an inverter,and a battery.

It only runs when the battery gets low,and idles down when the battery is fully charged.

The idea of using your truck gas tank is excellent

(if nobody steals your truck and generator).

Go for it.

Are you just running the blower for a gas furnace, or an electric heat pump. If it is just a blower, which means you have LP, just get a wall heater that is radiant, they are pretty efficient, there are models that don't require electricity, and in an emergency, they will easily keep the house at a sustainable above freezing mark, as long as they have a thermostat that will set low enough. (be sure to check before you buy)

I have the same problem in my case the house I am selling is 1 mile away. I have the same worry and I worry about a failure of the furnace. I have a camera looking at the temp in the house that I transmit to my house. If the house has a phone line

a answering machine with a thermostat could be used so you can call to see if it is to cold. Or a thermostat could short the phone line when to cold so when called it is busy. I also agree that the

warmer you keep it the faster you loose heat. Be sure to

keep doors under a sink to a outside wall open. A fan can be used so that warmer air blows on pipes that are in colder places.

I have a friend with a summer home and he blows out the pipes with air and it works ok for him but you can never be sure all the water is out. I have seen a I/2'' elbow pop open like a soda can from freezing.

How I wish Al Gore was right. 15 more weeks of this worry.

John

A few questions come to my mind:

Are you on municipal water system,or is it from a private well?

If it is from a private well,leave a faucet running about a toothpick size stream.

It will cycle the pump and refresh the water in the line to prevent freezing.

I used to live in the mountains at around 6200 ft, elevation and our water was

gravity fed from a spring on the hill.

We never turned the water off in the winter,always left each faucet with a slight

stream.

Never had a pipe to freeze unless a relative from out of town turned the faucets off.

Of course,the water was free,so no $ to worry about.

If your water is from a well, you would be better off to put the generator on the

pump,and leave the faucets slightly running,if your well has the capacity to handle it.

I don't know how cold it gets in your local,but we saw plenty of 15 and 20 below.

The genset has no inverter - I don't expect to have to use it a lot but was just curious about this. Not worried about the truck being stolen or the genset. We have signs that say "No Trespassing - you are within range!"

The house is well insulated and built for winters. We are in Maine...we know how to prevent pipes from freezing!

We can't "let the water run" since that requires the pump to run, and I'm only powering the Forced Hot Water (FHW) system. That also means there's no beer in the fridge since it's not running either. But we can leave a couple outside and hope they don't burst!

I realized that I could very easily use my garden tractor tank, which is parked right next to the genset. Just a couple of shut off valves and I'll be all set! And yes the genset is in a safe place OUTSIDE the garage which is not connected to the house.

Another source of fuel storage that is easy and cheap, go to a local salvage yard and pic out a fuel tank removed from a scraped vehicle (determine your required run time and size accordingly). I have two, one I am going to mount under my cargo trailer for fueling RVs and one that I use with my gen-set. If you have 12 volts DC available you can utilize the in tank fuel pump, if not set it up to feed just like your original tank. You may consider placing a solenoid valve in the line to stop the flow of fuel if the gen-set shutdown for some reason as a safety incase the float was to stick.

Good idea!

Tom: After reading and learning that you already have another larger genset for the whole house, I hit upon an idea:

(1) Use the FWH system for the guest house, but bring a supply and return to the main house, and set a heat recovery off the exhaust of the "big arse" genset. There should be more than enough heat available to keep the guest house above 40-50 °F. I don't know if your current set-up is for combined heat and power, but that seems to be a really good idea. (2) Since this would require a parasitic load to run the pump all the time (to prevent freezing) you would have to either pay for that pump running, or use a suitable heat transfer medium with insulated transfer lines. It might be better to simply have underground hot supply and cold return air ducts (mightily insulated), and only kick on the fan with the grid supply falls off.

In fact, there are commercial units (for residential use) that utilize a Stirling engine genset, and also provide the unutilized heat to the house when required. One of those in the guest house might be interesting.

You did not read where I noted that the "guest house" is 1/4 mile from the main house.

Then go acquire a new fuel tank, and keep things running to get at least 48 hours run time out of it, surely you can get more fuel in that time? You could still try the heat recovery idea to see if that gets you more bang for the buck.

Tom,

Notice that replies are all over the place? What is FHW? At first I thought it was a homemade acronym for Forced air Heat with Water, then maybe it was Floor Heated with water (as in radiant floor heat) then maybe it is something else, although you did mention pipes busting, and maybe you are talking about a Domestic Hot water Heater (DHW) which if it is a tank or tankless style would not keep your house from freezing, or the pipes, even with a recirc, since they often do not utilize the supply side of the plumbing. Several people suggested that you leave a drip from fixtures, which of course would not work if you are on a well that needed electricity to keep pumping, which would not be there if the power failed, so maybe you are considering powering the well pump with the genset. But you said you can set the house at 42 degrees, so what keeps it at 42. That would help.

There are not many pull start gensets that can run a resistance heat strip in a whole house HP (heatpump) which is likely at least 10KW, and would have to be if you saw -10 temps, I'm guessing you have NG or Propane..

Why don't you state what HVAC and DHW systems you have, and what you need to happen when the power fails, what fuels may be available. Looking forward to it.

This is another interesting CR4 thread where a simple question was asked, and we got to re-engineering my house, my guest house, and the genset! I love it!

Yes the answer (stated a couple of times I think) is to increase the capacity of the genset and hope we never need it!

It's the rare question that gets asked and answered here.

Mostly, they get asked and answered, and answered, and answered, and answered, and answered, and answered, and answered, and answered, and answered, and answered.

Goes with the territory.

Remember, Andy Germany hasn't added his advice yet. I'm sure there are more who will be willing to give you the benefit of their vast, or half vast wisdom.

Plenty of "half vast wisdom" here! Sometimes it just helps to be there to see the thing, to know what is necessary. Fuel tanks are definitely cheap. I personally would move to Texas, but hey, I am already in Texas.

If you own all of the land, I would just run a buried, (or on poles, trees?), dedicated wire from your big honkin' genset to the heater in the guest house.

You would never have to think about this again.

Don't plan on storing ethanol crap fuel for very long.

I have difficulty imagining the set-up from your description so forgive if what I write is of no use.
Very little persistent heat is needed to stop freezing and if your generator is used to supply halogen
fire bulbs (small fire units, using only e.g. 400 watts) strategically placed on time
switches to come on/off every hour (or thereabouts) will prevent the freezing.

For long periods of time, the generator could supply storage heaters which will prevent
freezing for several hours, much longer. The storage heaters can be had second hand
for only a few pounds, and I actually picked 2 up for free! (unwanted.)
Also a kerosene (paraffin) lamp can run all day on one filling. Not so effective as the
halogen or storage units, but better than having burst pipes. Hope this helps. jt.

Have you asked the Russian - Mr Ivan Freezabolakov ?

I use FHW to mean Forced Hot Water system but should actually refer to it as a Hydronic system. The genset runs the ignition system for the oil fired furnace and powers the circulators.

Here's how it works...

http://www.hydronicpros.com/hydronicheating/

oil fired hydronic. A small battery bank would be pretty straight forward, lots of recharge options. (Solar, grid, genset,)

You could size a bank that would last for 24 hours, my guess is that you would use less than 2 KWH per day on the circulators. If you had a battery bank/inverter setup that was rated at 6KWH, (2 12V AGM's at 240 Amps each is a common size used in solar systems) You could recharge this bank by running a 2500 watt generator for one hour. You will need an inverter with a charger, or you could do it with two components. If the power outage was less than 24 hours, you wouldn't even need to run the genset, the grid could do it automatically.running any generator continuously for 100 watts is a tough sell, but it is certainly the cheapest option.

2500 watts is not enough to START the system...I tried a 2500W inverter and a battery...would not fire the furnace ignition. That's why I have a 3600W genset!

Like many applications it's the start current that's the problem.

Is it a 240V circuit to the furnace? If it is 120V, and you can't get it to run with 2500 watts, something is amiss. (20 amps at 120V is less than 2500 watts) Maybe insufficient voltage on the battery or a toasted inverter, was causing the startup failure.

Yes I know the math...could have been the battery...I needed a good excuse to get a new genset though! _{Wife does not know watts from amps or volts!}

Methinks there be a ill-wind that blows here. Ye should hie thee hither from Maine to the Bahamas. Or you could actually invest about 30 minutes checking out why your system takes that much electric power to "even start", sumting wong here?

That's much simpler to understand, thank you. So you only need to have sufficient Electricity to power the ignition and the pump? Our pump only uses 500 watts, and the ignition is negligible, so I have it on an APC ups standby which automatically cuts in in the event of a power failure. The batteries last about 3-4 hours, but can be extended with more batteries, or a stand by generator, as you say.
Could this work for you?

jt.

When I was young I used to pray for a bike, then I realized that God doesn't work that way, so I stole a bike and prayed for forgiveness.

For what it is worth I run number 12 uv wire over 2000' to power TV and Radio equipment on my hill. I run 120 volts but if I needed more power to make up for loss in that long a wire you could find some transformers to step up to 600v and back down to 120 v. I feel for you about the cost for year after year heating and wonder how bad it is for the house to freeze other than the water. I would like some thoughts about that.

Well the land that I would need to run that wire on is farm land so it would be difficult to get wires either underground or on poles, without a lot more cost than to heat the place! I only run the heating system on idle during the winter unless we have guests, and that's usually only a few days at a time. Between April and October the heating system is turned off...again unless we have guests. So in all it may cost me $300-$400/year to heat the guest house. I get pretty good return from some of my guests as they are paying customers for our puppies. Yes I get to write a lot of my costs off for tax purposes.

Freezing the material in the house is not a good thing. We are talking about temperatures that could get to -20 f in a bad winter. That can buckle floors, crack tiles, and wall board, as well as shrink and expand all the joinery in the cabinets, doors, etc.

Again the answer to the question is - get a bigger gas tank on the gen set and let it run.

My father used to live in an orphanage near a reservation in Oklahoma. He gave a puppy to one of his native friends after one of their many football games. The family invited my Dad over later in the week for dinner. They were having stew. At some point Dad remarked about how good the stew was, complimenting the chef, and his friend's dad told my Dad: "Go ahead, (redacted), dig deeper get more puppy!" Dad was crestfallen.

I hope you are not in the puppy stew business (just kidding). Until we get LENR or something else to work that works better as temperatures decrease, bigger gas tank. Fortunately for right now, that price is looking pretty good (nobody has a job, except the guys in the oil patch, so nobody ain't goin' nowhere, and the price just keeps falling, or the Saudi Princesses are up to no good.