Natural Gas Whole House Power Backup?
- Thread starter jwilson56
- Start date
pete_c
Guru
I did the research for the same. Called the local gas company and they sent me a form for a second regulator-meter. They said that they would not charge me to install the natural gas line. Relating to size I was looking at about a 13Kw-15Kw unit. This would be more than I needed and would cover AC etc. At the time the price to drop ship said generator was less than $4000 which was over the internet and much cheaper than any of the local suppliers. I still have not installed it and have noticed more power outages in my newer home than the previous home.
fcwilt
Active Member
We put in one of this brand but it was for LP. Our unit came shipped to run on NG but by moving a lever it was "converted" to run on LP.
http://www.generac.com/Residential/
The 10 Kw unit seems to work well and is decently quiet.
http://www.generac.com/Residential/
The 10 Kw unit seems to work well and is decently quiet.
briankelly63
Active Member
Simply The Best !
http://www.kohlerpower.com/residential/cat...ionNumber=13561
http://www.kohlerpower.com/residential/sol...tentNumber=103#
If you really do the research on these you'll find that Kohler uses a much more sophisticated level of electronics in their units vs. other brands. Download a manual and take a look...
Brian
http://www.kohlerpower.com/residential/cat...ionNumber=13561
http://www.kohlerpower.com/residential/sol...tentNumber=103#
If you really do the research on these you'll find that Kohler uses a much more sophisticated level of electronics in their units vs. other brands. Download a manual and take a look...
Brian
I also have a 15Kwh air cooled Generac but on Propane. I think on natural it puts out 12 - 13Kwh.
Works great....since installing it there have been very few times it was needed
Looks like they have come out with a newer generation since mine. Mine is in a rectangular steel box and the current line look like they are now encased in plastic. I think I would opt for the steel but not sure what other changes they made. Maybe the newer are quieter. Not a huge deal for me.
fcwilt
Active Member
Care to elaborate?
I bought a Guardian (now Generac) model 5638 liquid cooled 22kW genset about a year ago. Had it installed a few weeks before Hurricane Ike hit. Our neighborhood was pretty lucky. We were without power for only four days. The genset ran flawlessly the whole time. Mine is about 150' from my house, on the other side of my "shop" so I can't hear it run. We couldn't even tell we were on genset power, and couldn't tell when utility company power came back.
Mine is set up as a whole house genset. The ATS sits in between the meter loop and my main load center. No "load shedding" or "emergency circuits" or anything like that. At the time, it was running an inefficient 4 ton A/C (a 20 year old 10 SEER that was replaced a couple of months ago), a 1.5 hp water well pump, two refrigerators, all lights, home entertainment, several computers, garage door opener, etc. My water heater and cooktop are LPG so that helped. We purposefully didn't use the electric oven just to be safe, but my guess is I could have with no problems. I was more concerned about a timing issue with all the major power users coming on at the same time, so we eliminated the oven from that possibility. My genset has a surge capacity of 38kW, so I never had any "startup" problems. I feed the genset with a dedicated 500 gallon LPG tank. I've since bought and installed "the Energy Detective" (will move to Brultech soon) to get an idea of energy usage. At "idle", my home consumes about 1.2kW. It will jump up as high as 3kW when a refrigerator is running, coffee pot on, etc. The new A/C seems to add another 3kW or so. The peak daily power seldom goes over 8kW, and I think the highest has been under 11kW. There may be some momentary surges caused by multiple motors starting that go higher, but TED doesn't see them.
I started looking at gensets after Katrina. I live on the Texas coast, and wanted to be prepared for a major outage. The key issues I came up with were air cooled vs. liquid cooled, 3600 rpm vs. 1800 rpm, and manufacturer. Almost all air cooled gensets run at 3600 rpm. Almost all liquid cooled gensets run at 1800 rpm. The overlap between air cooled and liquid cooled starts at about 15kW and goes up to maybe 22kW(?). I think Kohler has a 30kW liquid cooled that runs at 3600 rpm which is kind of unusual. It looks like it is the 15kW model at double speed. I read somewhere that the life expectancy of an air cooled genset is 3000 hours, whereas the life expectancy of a liquid cooled model is 10,000 hours. Until recently at least, air cooled gensets needed oil changes twice as often. A genset running at 1800 rpm will probably be quieter than one running at 3600 rpm if that is a concern. It will probably generate less heat, which may be an issue in hot climates. Most liquid cooled gensets use modified "truck engines". Mine uses a 2.4L 4 cyl Mitsubishi. Generac uses the same engine in their 27kW genset, so powering a 22kW generator is really easy on the engine. It isn't downrated on natural gas like many hensets are, suggesting that the engine is nowhere near it's limit with a 22kW generator. The engine almost never lugs down.
I went with Generac because it seemed to me that they were focusing on the residential market (selection, dealer network, etc.). The 5638 was exactly the size I figured I needed, and a similar genset from the other manufacturers cost significantly more. To me, the other manufacturers offered fewer choices in the small liquid cooled models. Also, it seemed like I would have to buy the genset from a manufacturer's distributor, then contract out the install/startup to one of their recommended installers (which was usually an electrical contractor). I wanted a turnkey package and to only deal with one entity, and the Guardian/Generac dealer was the only way I found to do that. And yes, I'm sure I paid a premium for that.
They can certainly have breakdowns. A few months after installation, the main wiring harness on mine developed a problem and had to be replaced. Diagnosing that problem took the dealer (and the factory) several months. A couple of months ago, the starter went out. Both of the problems were fixed under warranty. Even though I almost never buy extended warranties, I did for this thing. I also purchased the maintenance contract. My 5638 was one of the first out of the manufacturer's door, so that may have caused some problems, too.
I have maybe eight UPS's of various sizes (most between 1000 and 1500va) running at all times. I have not tweaked their sensitivity. Many are fairly old APC models that have a reputation for being very sensitive and not liking genset power. My dealer even warned me about this, and it's mentioned in the genset manual. During my four day "Ike outage", I heard UPS beeps maybe three or four times and only one or two beeps each time. My guess is that was when the A/C kicked on while the water well pump was running, or vice versa. That tells me two things...1) the genset power is very clean, and 2) it's able to keep the voltage/frequency correct even when a big surge hits it.
This is a good forum for Guardian/Generac gensets.
Mine is set up as a whole house genset. The ATS sits in between the meter loop and my main load center. No "load shedding" or "emergency circuits" or anything like that. At the time, it was running an inefficient 4 ton A/C (a 20 year old 10 SEER that was replaced a couple of months ago), a 1.5 hp water well pump, two refrigerators, all lights, home entertainment, several computers, garage door opener, etc. My water heater and cooktop are LPG so that helped. We purposefully didn't use the electric oven just to be safe, but my guess is I could have with no problems. I was more concerned about a timing issue with all the major power users coming on at the same time, so we eliminated the oven from that possibility. My genset has a surge capacity of 38kW, so I never had any "startup" problems. I feed the genset with a dedicated 500 gallon LPG tank. I've since bought and installed "the Energy Detective" (will move to Brultech soon) to get an idea of energy usage. At "idle", my home consumes about 1.2kW. It will jump up as high as 3kW when a refrigerator is running, coffee pot on, etc. The new A/C seems to add another 3kW or so. The peak daily power seldom goes over 8kW, and I think the highest has been under 11kW. There may be some momentary surges caused by multiple motors starting that go higher, but TED doesn't see them.
I started looking at gensets after Katrina. I live on the Texas coast, and wanted to be prepared for a major outage. The key issues I came up with were air cooled vs. liquid cooled, 3600 rpm vs. 1800 rpm, and manufacturer. Almost all air cooled gensets run at 3600 rpm. Almost all liquid cooled gensets run at 1800 rpm. The overlap between air cooled and liquid cooled starts at about 15kW and goes up to maybe 22kW(?). I think Kohler has a 30kW liquid cooled that runs at 3600 rpm which is kind of unusual. It looks like it is the 15kW model at double speed. I read somewhere that the life expectancy of an air cooled genset is 3000 hours, whereas the life expectancy of a liquid cooled model is 10,000 hours. Until recently at least, air cooled gensets needed oil changes twice as often. A genset running at 1800 rpm will probably be quieter than one running at 3600 rpm if that is a concern. It will probably generate less heat, which may be an issue in hot climates. Most liquid cooled gensets use modified "truck engines". Mine uses a 2.4L 4 cyl Mitsubishi. Generac uses the same engine in their 27kW genset, so powering a 22kW generator is really easy on the engine. It isn't downrated on natural gas like many hensets are, suggesting that the engine is nowhere near it's limit with a 22kW generator. The engine almost never lugs down.
I went with Generac because it seemed to me that they were focusing on the residential market (selection, dealer network, etc.). The 5638 was exactly the size I figured I needed, and a similar genset from the other manufacturers cost significantly more. To me, the other manufacturers offered fewer choices in the small liquid cooled models. Also, it seemed like I would have to buy the genset from a manufacturer's distributor, then contract out the install/startup to one of their recommended installers (which was usually an electrical contractor). I wanted a turnkey package and to only deal with one entity, and the Guardian/Generac dealer was the only way I found to do that. And yes, I'm sure I paid a premium for that.
They can certainly have breakdowns. A few months after installation, the main wiring harness on mine developed a problem and had to be replaced. Diagnosing that problem took the dealer (and the factory) several months. A couple of months ago, the starter went out. Both of the problems were fixed under warranty. Even though I almost never buy extended warranties, I did for this thing. I also purchased the maintenance contract. My 5638 was one of the first out of the manufacturer's door, so that may have caused some problems, too.
I have maybe eight UPS's of various sizes (most between 1000 and 1500va) running at all times. I have not tweaked their sensitivity. Many are fairly old APC models that have a reputation for being very sensitive and not liking genset power. My dealer even warned me about this, and it's mentioned in the genset manual. During my four day "Ike outage", I heard UPS beeps maybe three or four times and only one or two beeps each time. My guess is that was when the A/C kicked on while the water well pump was running, or vice versa. That tells me two things...1) the genset power is very clean, and 2) it's able to keep the voltage/frequency correct even when a big surge hits it.
This is a good forum for Guardian/Generac gensets.
briankelly63
Active Member
Without going back through the manuals... my impression as a technical person was that the unit had a sophisticated level of diagnostics, self checking, very tight engine - generator communication linkage, high quality assemble and wiring (ISO9001), great technical support, extensive manuals for self service, lots of test point documentation, industrial type transfer switches..... There is no assumption in these units that the engine or generator are just doing the right thing (as some others), there is a lot of monitoring, adjustable items on circuit board, short circuit protection and adjustment going on to maintain voltage, current and freq.
Kohler's PowerBoostâ„¢ voltage regulation system provides instant response to load changes
Overspeed shutdown
Low Oil Pressure shutdown
Electronic Ign
Cast iron for critical engine parts
Electronic governor
OHV Engine
Hyd Valve Adjusters
I have a Generac 27Kw liquid cooled with a load shedding panel. It was hard to find objective reviews and opinions between Generac and Kohler. It seems that Kohler is probably better, but without any real comparisons, it wasn't worth the 40-50% difference in cost to me. We've only had it in operation for 2 months now. Has been on only once, but no problems thus far.
miamicanes
Active Member
Slightly off-topic, but for anyone who has a portable generator that burns unleaded gasoline, it's possible to convert them to run from natural gas, propane, or all three. I don't remember the URL offhand, but there's at least one company that sells DIY kits to do the conversion yourself. I've been meaning to do it to mine ever since... well... about 3 months after Wilma, but haven't gotten around to it yet.
There IS one catch, though -- from what I've read, a converted generator running from natural gas or propane will only deliver about 80-90% of its gasoline-rated power output. For a 10-12kW generator running appliances, it's probably not a deal-breaker... but if you have a 5.5kW generator (like lots of people around here bought from Sears, Home Depot, and Sam's Club after Wilma), it COULD mean the difference between being able to run (or more precisely, START) a portable air conditioner and NOT being able to do it. Remember, a 5.5kW generator is really TWO 2.75kW circuits, and I think the rated power is PEAK, not RMS (could be wrong, though). 80% of 2750 is 2200. If the ratings are peak instead of RMS, and RMS is ~60% peak, that puts you *right* at the load requirements to RUN a 10,000BTU window air conditioner, and assumes the generator will have enough peak reserve to start up the compressor.
There IS one catch, though -- from what I've read, a converted generator running from natural gas or propane will only deliver about 80-90% of its gasoline-rated power output. For a 10-12kW generator running appliances, it's probably not a deal-breaker... but if you have a 5.5kW generator (like lots of people around here bought from Sears, Home Depot, and Sam's Club after Wilma), it COULD mean the difference between being able to run (or more precisely, START) a portable air conditioner and NOT being able to do it. Remember, a 5.5kW generator is really TWO 2.75kW circuits, and I think the rated power is PEAK, not RMS (could be wrong, though). 80% of 2750 is 2200. If the ratings are peak instead of RMS, and RMS is ~60% peak, that puts you *right* at the load requirements to RUN a 10,000BTU window air conditioner, and assumes the generator will have enough peak reserve to start up the compressor.
AceCannon
Active Member
I got an air-cooled Generac 20kw from Home Power Systems for < $4000. Also purchased a load-shedding transfer switch from them. Ziller Electric supports some online forums and also had competitive pricing, but there was something weird about them not wanting to unbundle the generator from the transfer switches.
The problem with the online purchase is you have to find someone to install. Or do it yourself. Contractor had the pad poured. The plumber does the NG. Electrician does the HV and transfer switch. I had my electrician also run the control wiring. He then made the control wire connections and the install was complete. So my impression is that you are paying quite a premium to have a local guy install the genset. (At least in new construction).
The yearly maintenance does not appear challenging. Home Power Systems sells maint kits for $40.
The problem with the online purchase is you have to find someone to install. Or do it yourself. Contractor had the pad poured. The plumber does the NG. Electrician does the HV and transfer switch. I had my electrician also run the control wiring. He then made the control wire connections and the install was complete. So my impression is that you are paying quite a premium to have a local guy install the genset. (At least in new construction).
The yearly maintenance does not appear challenging. Home Power Systems sells maint kits for $40.
Unfortunately, I don't remember all the differences between Generac and Kohler, but they were significant enough in my opinion to spend the extra money on the Kohler. I have the 30RES, a 30KW genset with an ATS. I use propane with a buried 400 gal tank. It's water-cooled but does run at 3600 RPM. It's very quiet, as water-cooled units are. I have 3700 sq ft house, and half way across the house I can't hear it running, and it's installed two feet from the house. Of course, this is with the windows closed.
Service and installation is ridiculously expensive on Kohlers, though, but they do a good job. I haven't had any problems with the unit since it was installed in 5/2008.
Kevin
Service and installation is ridiculously expensive on Kohlers, though, but they do a good job. I haven't had any problems with the unit since it was installed in 5/2008.
Kevin
Steve
Senior Member
I think the most expensive part and probably main reason I just stick with my portable is digging up the yard and putting a large tank in. Most homes here in SFL don't have gas lines run to them so a propane tank in the yard is usually the answer. But the cost of putting that in plus the cost of fills (and refill availability if needed during a storm) kind of keeps me on the portable.
Hi, Steve.
I'm in SWFL and did not have gas lines to the house. I had to bury a tank, but did it while under construction. I really wanted a 1,000 gal instead of 500, but codes required the 1,000 be 25' from the nearest structure, easement, etc, rather than the 15' the 500 gal required. As if I'm going to be safe if there was a rupture at either distance. I expect the propane will last up to a week with good energy management. If things are so bad that I can't get a refill in a week, wouldn't you have a bigger problem getting your gas cans refilled?
IAE, let's hope it's another quiet season. I hope the money I spent on the generator goes to waste and that I'll never need it.
Kevin
