I've found it useful to measure/control the thing you really care about. So, what do you care about?
If it were me, I'd care about the air/fuel ratio across the full load range.
So, what makes that happen? If it's a converted open-loop carburetor, the A/F ratio might be very pressure dependent. The only acceptable pressure drop might be "none".
If it's an injection system with feedback from the exhaust sensor, it might be relatively insensitive to supply line restriction.
The whole concept of "see what happens" falls apart if you can't actually see the thing you care about. In this case, it might be more appropriate to "hear what happens." After writing that, it occurs to me that I have no idea whether a natural gas engine exhibits knock when you run it lean.
That's a good point, and quite apropos of DD's manometer -- which I wish I had. And even if I did have one, what I really care about is voltage under load. If my welder drops the voltage by only a few %, I'll be a happy camper.
The listening advice is always good -- I don't want constant voltage with load if it's going to burn out the engine because of fuel issues. Funny, I tell that (about listening) to the guy that works with me, all the time: LISTEN to the machine (lathe, milling) -- it's your first indication when shit ain't right. That, and smoke/sparks..... LOL
Tonite is the night I start kluging stuff together electrically, see what happens. And hear what happens.... :)
}}Any decent gas line that has been run by a utility to a house will support a 15KW generator. The BTUs are in the range of a large residential gas furnace. Supply is clearly sized to support a lot more than that, because typically you also have water heater, stoves, gas grills, etc.
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One would think so but ... I mention the potential as we had the experience where the utility support was not sufficient. If that's not a problem for the OP fine. If it is then is it not better to be apprised of the potential then to be left in the dark?
BTW the untility engineering could not understand nor explain why the device was in the line.
My house has Nat Gas furnace - and water heater - not range or drier If I wanted to put in one of those insane tankless water heaters AND a range and drier, I would need a bigger meter and inlet line.
No shit harry? You figure that out? That it takes more energy in than out?
What a maroon. Has nothing to do with the fact that a typical house has a gas line from the utility more than adequate to run his genset.
harry, what happens when a typical house wants to add a swimming pool? The heater for a swimming pool is 200K to 400K BTUS? You think they have to run a new gas line to the street? Here's a clue. The gas is under higher pressure until it gets to the regulator at the house. It can supply plenty of gas. ====================================================
I see I'm not the only one you give a hard time to..... LOL
To be fair, not everyone is aware of those kinds of efficiency issues, either, so it was a fair reminder. In fact, most people are not aware of the drastic thermodynamic inefficiencies of heat engines. Makes you wonder about God....
Regarding that residential restriction, yeah, it proly is a rare thing, but it WAS a very inneresting factoid -- unfortunately for the guy who built the furnace.
BUT, it also remains to be seen if my gas service (and piping) can support a gas-fired furnace, kitchen stuff, hot water heater, AND a genset going full tilt -- poss. not at all a moot point during a deep-winter outage. But still, proly not a biggie even if there is a bottleneck somewhere -- things just won't be going 100%.
Also, in my neck of the woods, there is no gas regulator in the house. I don't know if that's good or bad. Mebbe there's one streetside. In fact, I don't ever recall seeing one in the NYC, Westch area -- not that I was looking, but that is something I woulda noticed, house-hunting etc.. Unique to NJ? I know some places have very high water pressure (100 psi), that needs a regulator house-side. That pressure can vary with where you physically are relative to the municipal water pumps.
Insane just about sums those things up. Can you imagine if EVERYONE had one of those things, gas or electric? They'd have to re-do the whole infrastructure of the city! Doubtful that they save an iota of energy, altho it would be nice to see objective data. Would make a good thread. Could crosspost to alt.hvac, and see what those greedy asshole prima donnas have to say. LOL
Besides natural gas are you planning on having other ways you can run it such as having a propane tank installed or something else? =======================================================
Proly just some BBQ type bottles hanging around, more for if for some reason I load the thing onto m'truck. But since I'm now an Oh-ficial Doomsday Prepper (thanks to fuknSandy), I got like 50 gals of gasoline tucked away, so I can always use that. This genset has a separate gas line/filter that you just drop in a gas can -- really nice, as you can set up multiple gas cans siphon-style, for really big capacity. Might also be able to just drop the hose into the gas tank of m'truck!! I'll have to check that out.
Another thing I wanted to do was put a spigot on my gas tank, so I could fill cans right from the truck. Heh, and pray that none of the neighborhood hoodlums know about my gas-tank spigot..... LOL Or, perhaps plumb sumpn in under the hood in the fuel pump line, and just let the fuel pump do the pumping?? I'll have to explore that, see how complicated the wiring would be for that.
Let's put it this way: If an outtage is so bad, so broad that you lose nat gas pressure, we are in *deep shit*. Nat gas almost never goes out. But if it does, that's the neat thing about tri-fuel.
Remember that hyooge blackout, that hit like 1/4 of the US/Northeast?? I wonder if nat gas was lost in that thing.... Fortunately, since it wadn't really storm/disaster related, power came back in about 24 hrs. I think nat gas pressure WAS lost, bec I seem to remember some issues in some buildings, restarting pilots and alladat. Mebbe someone here knows f'sure.
When was Nat Gas connected originally to your house ? How big is the pipe leading to your meter ? My house was built in 53 I just added a high performance kitchen stove. The smallest burner at full power is 20,000 BTU. All I needed was a 1 " connection to the stove if shared, or 3/4" if not I have been replacing all black pipe with 1" flexible hose. I can turn on ALL burners on the stove, with furnace, hot water and dryer running all at once, and I have ample Nat Gas to power everything at capacity.
Also why is a tankless water heater "insane" ? They have been in use in Europe for 40+ years. The modern ones are quite efficient.
Something you can make easily -- especially for the pressure levels involved in natural gas.
Get some clear plastic hose/tubing.
Get a board about four feet long or so, and mount it upright.
Attach the tubing to the board to form a 'U', with the open end of the U facing up.
Keep one end totally open, and the other end connected to your gas feed pipe. (Probably fix things up so you can connect it at either the supply end or close to the generator -- or even make two of them so you can measure both at once.)
Pour enough water into it so you have at least as few inches of water as the maximum pressure from the gas company's regulator. (This is actually twice as much as you need, but reduces the chances of things spraying out during a pulse of pressure.
Mount a yardstick between the pipes which can be slid up or down, so the zero point can be lined up with the water level in the lower of the two pipes.
Then measure the inches from the top of the low end to the top of the high end, and that is your pressure in inches of water.
For higher pressures, you either need a longer board and tubing, or to replace the water with mercury (there about 29" is equal to atmospheric pressure).
You'll need to continue that arc for a while, to allow the pressure in the pipe to adjust to conditions -- it won't be immediate, as the pipe will act as a reservoir for a while.
Always best to check with the utility I guess. I just quickly looked at a tankless heater spec and it wants 3/4" supply and says to check with the utility as to supply from the meter. I have NG furnace, tank water heater, dryer and range/oven. House was built in '59, Chicago suburb. Main feed in the house is a 1 1/2" running to the furnace. Then a double reducer tee, 3/4" straight ahead and 3/4" 90. The 3/4" 90 feeds the furnace, the straight 3/4" has a single reducer tee a bit down the line feeding 1/2" to water heater, then a tee feeding 3/4" upstairs to the upstairs stove, then a final reducer coupling feeding 1/2" to the dryer. I thought it odd there's 3/4" for the upstairs stove, but looking at this chart
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says a stove uses more BTU than the water heater or dryer. Seems the water heater puts out more flame than the 4 range burners and oven burner combined, but I'm probably just wrong about that. Anyway, everything works fine. And though the inside main line is 1 1/2" the outside gas meter has
1 1/4" in and out. EA should probably should add up the total BTU's he uses and see what the utility says. Then he can address pipe size.
tankless water heaters have major downsides, some have no hot water in a power failure, during a 3 day power outage a hot shower is very important.....
many areas have regulators at each meter its called a high pressure system.
i have a friend in a low pressure system area, just a single neighborhood regulator....
its always better to a little oversize on supply lines
It will depend whereabouts on the gas grid you are. Outside my house there happens to be a twelve inch gas main. But most people will only have a two inch or so pipe nearby. And the size of your pool heater depends on the size of the pool, the local climate and how well insulated it is shitfor brains
It's bad there is no regulator. It means your gas pressure will vary widely depending on usage. It also means every bit of gas equipment will be running less efficiently than it might. It also means the gas is distributed at low pressure so there is less available than there would be if it were distributed at high pressure. You also have to take into account your neighbours gas using activities.
They save a lot of fuel. Because they are only on for a few minutes, they are not likely all to be on at once. They are very common in the UK, don't cause any problem.
What you actually want is a solid (wood?) burning stove with hotplate (+possibly oven) for cooking and a stock of wood. No-one can then take your fuel supply away/cut it off.
In my house, I can function without electricity.
There will be no petrol, gas,electricity or food after doomsday. But you can relax. The Mayas thing was lies.
They save a lot of fuel. Because they are only on for a few minutes, they are not likely all to be on at once. ===================================================
They would be, between 6 am and 8 am!! And between 4 pm and 7 pm, and 10 pm-12pm.....
The problem is the DEMAND, used in the utility-supplier sense.. The small bitty tankless bathroom sink ditties I see scattered in my workplace are, like, *4 kW*!!!!! I looked up some of the others, and holy shit, we're talking BIG wattage. You can exceed the entire power rating to a house, with just a few of those turned on simultaneously.
And I could see electric tankless being much better than gas tankless, for the same reason that convection ovens are almost always electric --- no wasted exhaust.
I'm sure there are some situations where tankless is appropriate. But I'd have to see real (read: honest) data showing the savings over *properly set-up* conventional stuff.
So I'm not betting the farm that I'm right, just think tankless is a kind of prematurely hyped new technology. Proly time to start a separate thread. :)
It's bad there is no regulator. It means your gas pressure will vary widely depending on usage. It also means every bit of gas equipment will be running less efficiently than it might. It also means the gas is distributed at low pressure so there is less available than there would be if it were distributed at high pressure. You also have to take into account your neighbours gas using activities. =======================================================
Good points, makes sense. Now I wonder why a place like NYC don't have'em!! And yeah, our gas pressure is low, like 5-7" water, or thereabouts. You could pop the cap off a 2" pipe, and stop the gas EASILY with the palm of your hand.
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