quiet natural gas generators

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Post Reply
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

quiet natural gas generators

Post by mouses »

I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
Valuethinker
Posts: 49030
Joined: Fri May 11, 2007 11:07 am

Re: quiet natural gas generators

Post by Valuethinker »

mouses wrote: Tue Nov 28, 2017 6:27 am I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
You can get a noise absorbing housing. That should cut about 10 db off the sound level, I believe. Remembering decibels is a log scale, that's significant.

https://www.consumerreports.org/cro/gen ... ying-guide

https://www.consumerreports.org/video/v ... enerators/
lazydavid
Posts: 5155
Joined: Wed Apr 06, 2016 1:37 pm

Re: quiet natural gas generators

Post by lazydavid »

They don't need to be inverters, they just have to be (more) expensive. The standard backup generators you see offered (at HD, Costco, etc, along with most home services) use two-pole motors connected to air-cooled engines running at 3600 rpm. These are fairly loud, although good baffling and placement can help somewhat.

Most of the major generator manufacturers (Generac, Kohler, Cummins Onan, etc) also make higher-end units that use four-pole motors connected to water-cooled engines running at 1800 rpm. These are DRAMATICALLY quieter, even before baffling is taken into account. But they use more expensive parts, so they cost more. Ballpark a 20kW unit of the first type will run around $5k (without installation), whereas one of the second type will be more like $8-9k. If you need more than 22kW, you have to go the liquid-cooled route, as that's all that's available.

If you don't want to spend for the higher-end units, my research suggests that the air-cooled Cummins Onan gensets are a little bit quieter than their Generac and Kohler counterparts, due to slightly better baffling design that directs the sound at the ground instead of out the side. But it's likely to be a small difference, 2-3dB at most.
User avatar
Lemonaid56
Posts: 264
Joined: Thu Mar 03, 2016 1:15 pm
Location: Maine

Re: quiet natural gas generators

Post by Lemonaid56 »

We have had a propane fueled Briggs and Stratton generator for 12 years. Has had very few issues. It does make noise tho. I installed it behind the garage to minimize the noise but I would equate it to an average lawn mower sound.

It is possible that having it mounted directly behind the garage is causing the sound to reverberate more off the back wall of the garage.

I would also recommend having the unit mounted a few feet off the ground. As the one that does the oil changes and maintenance on the the engine it is easier on the back and better than squatting on my knees in the dirt. I also worry less about it being buried in the snow during our average snow storms or should there be a flood it would have a better chance at surviving.
User avatar
TomatoTomahto
Posts: 17158
Joined: Mon Apr 11, 2011 1:48 pm

Re: quiet natural gas generators

Post by TomatoTomahto »

In my neighborhood, most houses have whole-house generators. Fwiw, from the stabledoor/horses file, we have few outages now. But, an unscientific but actionable survey I did showed that, of the generators in my neighborhood, the Kohlers were much quieter than the Generacs. We bought a Kohler.
I get the FI part but not the RE part of FIRE.
Call_Me_Op
Posts: 9881
Joined: Mon Sep 07, 2009 2:57 pm
Location: Milky Way

Re: quiet natural gas generators

Post by Call_Me_Op »

mouses wrote: Tue Nov 28, 2017 6:27 am I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
When I looked into this a few years ago, the two issues were noise (angry neighbors) and the fact that you need to keep them clear of snow. I dont want to be outside in the middle of a blizzard trying to clear snow from my generator.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein
Ron
Posts: 6972
Joined: Fri Feb 23, 2007 6:46 pm
Location: Allentown–Bethlehem–Easton, PA-NJ Metropolitan Statistical Area

Re: quiet natural gas generators

Post by Ron »

Call_Me_Op wrote: Tue Nov 28, 2017 8:05 am<snip..>When I looked into this a few years ago, the two issues were noise (angry neighbors) and the fact that you need to keep them clear of snow. I dont want to be outside in the middle of a blizzard trying to clear snow from my generator.
A few shovel fulls of snow to clear the vents are certainly a better option (IMHO) to be without power during a blizzard.

Been there, done that with my 20KW Generac :mrgreen: ...

BTW, there are no angry neighbors that I know of in our area. There are backup units (whole house - both Generac & Kohler) at eight homes (that I know of) within a one block area of my home. And the rest? They are happy to have a line thrown to them (through the snow) so they have limited access to power, if need be.

- Ron
likegarden
Posts: 3181
Joined: Mon Feb 26, 2007 4:33 pm

Re: quiet natural gas generators

Post by likegarden »

A friend has a Generac generator and no problems. The installer was experienced, and the generator does its weekly self-tests without problems. Others I heard complain that their generator not reliably starts up, so select an experienced installer. We have very few power outages, perhaps one 5 hour outage per year only, so we have no generator.
User avatar
ResearchMed
Posts: 16795
Joined: Fri Dec 26, 2008 10:25 pm

Re: quiet natural gas generators

Post by ResearchMed »

Call_Me_Op wrote: Tue Nov 28, 2017 8:05 am
mouses wrote: Tue Nov 28, 2017 6:27 am I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
When I looked into this a few years ago, the two issues were noise (angry neighbors) and the fact that you need to keep them clear of snow. I dont want to be outside in the middle of a blizzard trying to clear snow from my generator.
We've ask the guys who plow and shovel our snow if they could just scoot around the side and clear the generator, making sure that the vented sides are cleared well.
If it's a deep, prolonged snow, then their tracks each time just keep a nice path open. It's maybe 30 feet from the closest part of the driveway they've just plowed.
(We can also look out the window to make sure it stays clear. Snow sliding off the roof can land there. Yeah, not the best siting plan, but it's the same along the entire side, plus this is closest to the nat gas line.)

Just after the generator is serviced, it's always much quieter, and then when they close the lid, it's even "more quieter" :happy
The housing has what appears to be foam insulation on all sides, plus under the top, and that seems to make a big difference.
We can hear it from the window it is directly under, but it's not a big concern anywhere else.

We'd MUCH rather have it chugging along if there is no power, than be without power.
And it's very comforting to hear that weekly self test.
Even more comforting are the few brief outages when it starts like a charm under more realistic circumstances.
The longest we've had (other than the more than a day *prior* to getting the generator installed) is about 10 hours, and it was good to know for sure that all systems worked... that we hadn't forgotten any electrical thermostats or ignitions for the gas systems, etc.

Ours is a Generac, and so far, we are quite satisfied.
We had to have the gas re-piped, and also get a thick cement pad for it, but fortunately, we've got a good "plumbing and gas guy". He had an electrician join him for the final connections, of course.

RM
This signature is a placebo. You are in the control group.
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

Re: quiet natural gas generators

Post by mouses »

ResearchMed wrote: Tue Nov 28, 2017 9:23 am
Call_Me_Op wrote: Tue Nov 28, 2017 8:05 am
mouses wrote: Tue Nov 28, 2017 6:27 am I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
When I looked into this a few years ago, the two issues were noise (angry neighbors) and the fact that you need to keep them clear of snow. I dont want to be outside in the middle of a blizzard trying to clear snow from my generator.
We've ask the guys who plow and shovel our snow if they could just scoot around the side and clear the generator, making sure that the vented sides are cleared well.
If it's a deep, prolonged snow, then their tracks each time just keep a nice path open. It's maybe 30 feet from the closest part of the driveway they've just plowed.
(We can also look out the window to make sure it stays clear. Snow sliding off the roof can land there. Yeah, not the best siting plan, but it's the same along the entire side, plus this is closest to the nat gas line.)

Just after the generator is serviced, it's always much quieter, and then when they close the lid, it's even "more quieter" :happy
The housing has what appears to be foam insulation on all sides, plus under the top, and that seems to make a big difference.
We can hear it from the window it is directly under, but it's not a big concern anywhere else.

We'd MUCH rather have it chugging along if there is no power, than be without power.
And it's very comforting to hear that weekly self test.
Even more comforting are the few brief outages when it starts like a charm under more realistic circumstances.
The longest we've had (other than the more than a day *prior* to getting the generator installed) is about 10 hours, and it was good to know for sure that all systems worked... that we hadn't forgotten any electrical thermostats or ignitions for the gas systems, etc.

Ours is a Generac, and so far, we are quite satisfied.
We had to have the gas re-piped, and also get a thick cement pad for it, but fortunately, we've got a good "plumbing and gas guy". He had an electrician join him for the final connections, of course.

RM
Do you remember which model you got? Was the foamish housing an extra? Thank you.
User avatar
Epsilon Delta
Posts: 8090
Joined: Thu Apr 28, 2011 7:00 pm

Re: quiet natural gas generators

Post by Epsilon Delta »

I never ran the generator 24/7. Usually a couple of hours in the morning and perhaps six hours during the evening was enough. A few battery powered devices and thermal inertia filled in the rest. This was mostly to conserve propane (in case the power outage ran to weeks) but partly to conserve sleep.
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

Re: quiet natural gas generators

Post by mouses »

Epsilon Delta wrote: Tue Nov 28, 2017 1:23 pm I never ran the generator 24/7. Usually a couple of hours in the morning and perhaps six hours during the evening was enough. A few battery powered devices and thermal inertia filled in the rest. This was mostly to conserve propane (in case the power outage ran to weeks) but partly to conserve sleep.
When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

TomatoTomahto wrote: Tue Nov 28, 2017 7:48 am In my neighborhood, most houses have whole-house generators. Fwiw, from the stabledoor/horses file, we have few outages now. But, an unscientific but actionable survey I did showed that, of the generators in my neighborhood, the Kohlers were much quieter than the Generacs. We bought a Kohler.
We have a Kohler as well (20 kw, natural gas, air cooled). I have posted before that it sounds like a lawnmower and I stand by that. I just serviced it last weekend so ran it a couple of times with the enclosure cover open (once to heat the oil before draining it and once for a few minutes before checking it after refilling) and it's definitely louder than my mowers with the cover open. That being said, as someone else pointed out, it is MUCH quieter with the cover closed and even quieter still when you are inside the house. When I am working from home and it self tests I don't know it is on. If you are standing in the room closest to where the generator pad is and it self tests (and there aren't any other noises - TV, etc.) then you can hear it outside and it sounds like someone is mowing their lawn. It wouldn't bother you if you were sleeping (it doesn't bother us anyway). If you are particularly sensitive to noise then you can mount it further away from your house or even on a pad inside a small privacy fence at the back of your property or something. Honestly, the noise isn't an issue.
nickjoy
Posts: 91
Joined: Tue Jun 06, 2017 9:44 am

Re: quiet natural gas generators

Post by nickjoy »

I would suggest regular gas generators. If you're worried about being snowed in for multiple days, it's really nice to have all of your machines on one fuel source. That way, if you are snowed in for a long time, you can siphon gas out of your cars/lawnmowers/snowblowers/etc. to fuel your generator to keep your pipes from freezing. (military uses JP-8 as a fuel source for everything for this very purpose)

I have a big Honda generator on wheels. Yeah, it's loud. But that's why I put it outside and run the wires to plug into my father's house's circuit board under the garage door (door is slightly open). This keeps the noise outside.

Only thing I gotta worry about is people stealing it. But a chain would stop that.

If you don't get one of those permanent house ones. Make sure it has wheels. I'm young and am over lifting and moving them by hand onto dollies and whatnot.
GAAP
Posts: 2556
Joined: Fri Apr 08, 2016 12:41 pm

Re: quiet natural gas generators

Post by GAAP »

Might want to look at generators that are designed for the "off-the-grid" market -- they tend to be a little quieter, since that market expects regular (nightly) usage.
User avatar
ResearchMed
Posts: 16795
Joined: Fri Dec 26, 2008 10:25 pm

Re: quiet natural gas generators

Post by ResearchMed »

mouses wrote: Tue Nov 28, 2017 11:41 am
ResearchMed wrote: Tue Nov 28, 2017 9:23 am
Call_Me_Op wrote: Tue Nov 28, 2017 8:05 am
mouses wrote: Tue Nov 28, 2017 6:27 am I'm thinking about getting a natural gas generator, after multiple days power failures in the last few years in my area.

I have heard that generators can be quite noisy, one post said like a lawn mover, which I assume means a gasoline powered lawn mower. I sure wouldn't want to be listening to that for multiple days 24/7.

Reading up, it seems inverter generators are supposed to be the quietest. I had seen Generac generators recommended, so I asked them and theirs aren't inverters.

Anyone have words of wisdom about noise and generators?

Thanks.
When I looked into this a few years ago, the two issues were noise (angry neighbors) and the fact that you need to keep them clear of snow. I dont want to be outside in the middle of a blizzard trying to clear snow from my generator.
We've ask the guys who plow and shovel our snow if they could just scoot around the side and clear the generator, making sure that the vented sides are cleared well.
If it's a deep, prolonged snow, then their tracks each time just keep a nice path open. It's maybe 30 feet from the closest part of the driveway they've just plowed.
(We can also look out the window to make sure it stays clear. Snow sliding off the roof can land there. Yeah, not the best siting plan, but it's the same along the entire side, plus this is closest to the nat gas line.)

Just after the generator is serviced, it's always much quieter, and then when they close the lid, it's even "more quieter" :happy
The housing has what appears to be foam insulation on all sides, plus under the top, and that seems to make a big difference.
We can hear it from the window it is directly under, but it's not a big concern anywhere else.

We'd MUCH rather have it chugging along if there is no power, than be without power.
And it's very comforting to hear that weekly self test.
Even more comforting are the few brief outages when it starts like a charm under more realistic circumstances.
The longest we've had (other than the more than a day *prior* to getting the generator installed) is about 10 hours, and it was good to know for sure that all systems worked... that we hadn't forgotten any electrical thermostats or ignitions for the gas systems, etc.

Ours is a Generac, and so far, we are quite satisfied.
We had to have the gas re-piped, and also get a thick cement pad for it, but fortunately, we've got a good "plumbing and gas guy". He had an electrician join him for the final connections, of course.

RM
Do you remember which model you got? Was the foamish housing an extra? Thank you.
I could look, but don't remember.

We just discussed what needed to be covered... which circuits (including all heat thermostats/starters) some lights and plugs, all stairway lights, the *sump pump*, a fridge, but not the electric ovens, and not the AC.
Most of our concern was for winter (pipes freezing, us freezing), but in case of a Sandy-like event, that sump pump would be critical.
And then, maybe the AC would be something we'd want, but we figure we can make do.
I might be wrong, but I'm hoping that a summer rain/water "event" wouldn't coincide with a record-breaking heat wave. Small fans or the AC fan (without AC - they are separate controls, fan can run without AC, but not vice versa) hopefully would suffice.

Our "plumbing/gas guy" just made a recommendation, and he's seemed to get the right things/services for us for a very long time now.
The foam type material wasn't discussed. Either he just included it as an option, or it wasn't optional.
Judging the noise before the lid (with foam) was lowered, I'm guessing that for retail installations near a home, it would be included. But check!

You might just ask when getting estimates, about the sound factor.

In addition to the few actual uses thus far, the peace of mind when we hear a blizzard is coming, or ice storm, etc.... that's a considerably benefit.

RM
This signature is a placebo. You are in the control group.
killjoy2012
Posts: 1329
Joined: Wed Sep 26, 2012 5:30 pm

Re: quiet natural gas generators

Post by killjoy2012 »

mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

Re: quiet natural gas generators

Post by mouses »

killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
Valuethinker
Posts: 49030
Joined: Fri May 11, 2007 11:07 am

Re: quiet natural gas generators

Post by Valuethinker »

mouses wrote: Wed Nov 29, 2017 5:04 pm
killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
You will need to do an estimate of max current-- it could run to quite a bit. I don't know if there is a way of staggering the load as it comes on, but the surge could trip the circuit breaker quite easily.

There is a safety switch that needs to be put between you and the electricity mains. Otherwise, there is a risk that when the utility worker comes to switch back on the power, you electrocute them (that should not happen, but even the best trained people sometimes get careless). Somebody with more knowledge can tell you what that is, but whoever installs your system should know about it.
Valuethinker
Posts: 49030
Joined: Fri May 11, 2007 11:07 am

Re: quiet natural gas generators

Post by Valuethinker »

nickjoy wrote: Wed Nov 29, 2017 12:37 pm I would suggest regular gas generators. If you're worried about being snowed in for multiple days, it's really nice to have all of your machines on one fuel source. That way, if you are snowed in for a long time, you can siphon gas out of your cars/lawnmowers/snowblowers/etc. to fuel your generator to keep your pipes from freezing. (military uses JP-8 as a fuel source for everything for this very purpose)
I think that a NG generator is preferred over a gasoline one if at all possible. It's cleaner, cheaper to run, does not have the storage issues that gasoline brings.
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

Valuethinker wrote: Wed Nov 29, 2017 5:26 pm
mouses wrote: Wed Nov 29, 2017 5:04 pm
killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
You will need to do an estimate of max current-- it could run to quite a bit. I don't know if there is a way of staggering the load as it comes on, but the surge could trip the circuit breaker quite easily.

There is a safety switch that needs to be put between you and the electricity mains. Otherwise, there is a risk that when the utility worker comes to switch back on the power, you electrocute them (that should not happen, but even the best trained people sometimes get careless). Somebody with more knowledge can tell you what that is, but whoever installs your system should know about it.
VT is spot on. He's looking for an automatic transfer switch. Those are standard with whole house installs and handle the whole issue of backfeeding the grid as well as automatically sensing when you have lost utility power, spinning up the generator and then cutting you over to generator power (and back again once utility power is restored). It happens in seconds. Additionally, you can play with the size a little bit if you want by looking into load shedding. Load shedding does exactly what it sounds like it does - sheds loads when you hit max draw on the generator. We have two zones so 2 3-5 ton AC units and we also threw a load shedding module on our dual electric wall ovens. So what happens is if we have both AC units running and a whole bunch of other stuff in the house and we hit max load it will drop the electric wall ovens so we don't go over max capacity. If we approach max capacity again it will then shed the AC in zone 2 (the guest rooms and basement) and lastly it will shed the AC in zone 1 (living areas and master suite). We also installed hard start capacitors in both our AC units to lessen the initial surge they require when they first spin up. The folks that come to quote your generator will walk around with you and look at all your stuff as well as all the panels in your house (we have a main and two subs). They will help you figure out what will work best given your needs.
iamlucky13
Posts: 3527
Joined: Sat Mar 04, 2017 4:28 pm
Location: Western Washington

Re: quiet natural gas generators

Post by iamlucky13 »

Valuethinker wrote: Wed Nov 29, 2017 5:26 pm
mouses wrote: Wed Nov 29, 2017 5:04 pm
killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
You will need to do an estimate of max current-- it could run to quite a bit. I don't know if there is a way of staggering the load as it comes on, but the surge could trip the circuit breaker quite easily.

There is a safety switch that needs to be put between you and the electricity mains. Otherwise, there is a risk that when the utility worker comes to switch back on the power, you electrocute them (that should not happen, but even the best trained people sometimes get careless). Somebody with more knowledge can tell you what that is, but whoever installs your system should know about it.
The transfer switch is legally required. The installer will know this, although obviously DIY'ers need to look up the requirements.

There is an option to get a load-shedding panel connected to the transfer switch to keep from overloading the generator. Unimportant loads are delayed from turning on immediately when the generator comes on, and are automatically shut off if the generator starts to bog down.

I'll also point out to mouses that the system cost can probably be held down a decent amount if you're willing to forego those space heaters and the washer, dryer, and dishwasher for the duration of the outage, due to a smaller generator and fewer circuits to connect to the transfer switch.
Boglegrappler
Posts: 1489
Joined: Wed Aug 01, 2012 9:24 am

Re: quiet natural gas generators

Post by Boglegrappler »

The 20-40kw generators running on propane or natural gas will make noise at about the level of a pickup truck idling. Its not that quiet if you're 15 feet away with the windows open, but if you're in a neighborhood where house spacing is is decently far, it won't be something that bothers your neighbors. Its quite a bit more quiet than a lawnmower. I have to open the window to hear if my generator is still running even though its only 8 feet from the window.
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

I'll test the decibel level of mine vs. my lawnmower this weekend and report back. Maybe you guys are right and I'm way off and it is a lot quieter. My perception of how loud it is could be tainted from running it with the cover open whilst standing over it doing annual maintenance too. I'm usually not near it when it exercises or is running in an outage.
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

Re: quiet natural gas generators

Post by mouses »

There's a lot of great information in this thread, I really appreciate it.
User avatar
TomatoTomahto
Posts: 17158
Joined: Mon Apr 11, 2011 1:48 pm

Re: quiet natural gas generators

Post by TomatoTomahto »

We don’t have an auto load shedding switch, but we do have a box that controls which of our larger AC units run. Usually, in a power outage, we just cool the upstairs where the bedrooms are, and the downstairs stays cool enough.

20kw isn’t enough power for the entire house, but it is much better than the days we spent without any power.
I get the FI part but not the RE part of FIRE.
User avatar
ResearchMed
Posts: 16795
Joined: Fri Dec 26, 2008 10:25 pm

Re: quiet natural gas generators

Post by ResearchMed »

queso wrote: Wed Nov 29, 2017 5:30 pm
Valuethinker wrote: Wed Nov 29, 2017 5:26 pm
mouses wrote: Wed Nov 29, 2017 5:04 pm
killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
mouses wrote: Tue Nov 28, 2017 1:26 pm When it's near zero outside or over 90 in the house in summer, I really need the generator running almost all of the time.
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
You will need to do an estimate of max current-- it could run to quite a bit. I don't know if there is a way of staggering the load as it comes on, but the surge could trip the circuit breaker quite easily.

There is a safety switch that needs to be put between you and the electricity mains. Otherwise, there is a risk that when the utility worker comes to switch back on the power, you electrocute them (that should not happen, but even the best trained people sometimes get careless). Somebody with more knowledge can tell you what that is, but whoever installs your system should know about it.
VT is spot on. He's looking for an automatic transfer switch. Those are standard with whole house installs and handle the whole issue of backfeeding the grid as well as automatically sensing when you have lost utility power, spinning up the generator and then cutting you over to generator power (and back again once utility power is restored). It happens in seconds. Additionally, you can play with the size a little bit if you want by looking into load shedding. Load shedding does exactly what it sounds like it does - sheds loads when you hit max draw on the generator. We have two zones so 2 3-5 ton AC units and we also threw a load shedding module on our dual electric wall ovens. So what happens is if we have both AC units running and a whole bunch of other stuff in the house and we hit max load it will drop the electric wall ovens so we don't go over max capacity. If we approach max capacity again it will then shed the AC in zone 2 (the guest rooms and basement) and lastly it will shed the AC in zone 1 (living areas and master suite). We also installed hard start capacitors in both our AC units to lessen the initial surge they require when they first spin up. The folks that come to quote your generator will walk around with you and look at all your stuff as well as all the panels in your house (we have a main and two subs). They will help you figure out what will work best given your needs.
Never heard of "load shedding".
Can this be added after the generator is connected?

This timing might be fortuitous, if so.
We are about to have the electrician come back to change a few circuits.
As long as he's here, if a load shedding module could be added, maybe we could add a few circuits back in, in case of extended use.

Mouses... the sound within the house (with ancient single pane windows, NO soundproofing anywhere, and we suspect just about no insulation, unfortunately) is much *less* than those noisy leaf blowers, which are much, much more annoying throughout the entire house, regardless of where they are being used, even by neighbors.
If we are right next to the generator, inside, yes, it's a bit noisy, but still not like those leaf blowers.
Anywhere else in the house, barely noticeable.
Any well insulated home would presumably have even less noise inside.

Bottom line, we just don't find the noise troublesome, even the few times it was on for hours.
(But keep in mind, we don't find the noise a problem, but others might. For comparison, we *do* find those leaf blowers very annoying!)

RM
This signature is a placebo. You are in the control group.
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

TomatoTomahto wrote: Wed Nov 29, 2017 6:58 pm We don’t have an auto load shedding switch, but we do have a box that controls which of our larger AC units run. Usually, in a power outage, we just cool the upstairs where the bedrooms are, and the downstairs stays cool enough.

20kw isn’t enough power for the entire house, but it is much better than the days we spent without any power.
+1. We went through a similar cost/benefit analysis and figured that we almost never run the ENTIRE house anyway so the chances of us needing to do it in a power outage are pretty low. The 20kw came in at a better price point and let's us run almost everything at the same time so there's nothing we're really missing in an outage scenario. In a winter outage we can probably run everything or darn close to it since we have gas furnaces and those pull a ton less electrical power than the AC units do. The real problem with the AC units is peak draw at startup since it is multiples higher at start vs. running.
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

ResearchMed wrote: Wed Nov 29, 2017 7:34 pm
queso wrote: Wed Nov 29, 2017 5:30 pm
Valuethinker wrote: Wed Nov 29, 2017 5:26 pm
mouses wrote: Wed Nov 29, 2017 5:04 pm
killjoy2012 wrote: Wed Nov 29, 2017 4:52 pm
This comment from the OP generally excludes most portable units, and puts you in the whole house market -- assuming you mean that you want to be able to run your central air + point of use needs off of the generator.
Yes, I'm looking for one that runs off natural gas, starts and stops automatically. And runs the AC, pump for the gas heated baseboard heating, two space heaters, septic system, sump pump, frig, washer, dryer, dishwasher, misc lights.
You will need to do an estimate of max current-- it could run to quite a bit. I don't know if there is a way of staggering the load as it comes on, but the surge could trip the circuit breaker quite easily.

There is a safety switch that needs to be put between you and the electricity mains. Otherwise, there is a risk that when the utility worker comes to switch back on the power, you electrocute them (that should not happen, but even the best trained people sometimes get careless). Somebody with more knowledge can tell you what that is, but whoever installs your system should know about it.
VT is spot on. He's looking for an automatic transfer switch. Those are standard with whole house installs and handle the whole issue of backfeeding the grid as well as automatically sensing when you have lost utility power, spinning up the generator and then cutting you over to generator power (and back again once utility power is restored). It happens in seconds. Additionally, you can play with the size a little bit if you want by looking into load shedding. Load shedding does exactly what it sounds like it does - sheds loads when you hit max draw on the generator. We have two zones so 2 3-5 ton AC units and we also threw a load shedding module on our dual electric wall ovens. So what happens is if we have both AC units running and a whole bunch of other stuff in the house and we hit max load it will drop the electric wall ovens so we don't go over max capacity. If we approach max capacity again it will then shed the AC in zone 2 (the guest rooms and basement) and lastly it will shed the AC in zone 1 (living areas and master suite). We also installed hard start capacitors in both our AC units to lessen the initial surge they require when they first spin up. The folks that come to quote your generator will walk around with you and look at all your stuff as well as all the panels in your house (we have a main and two subs). They will help you figure out what will work best given your needs.
Never heard of "load shedding".
Can this be added after the generator is connected?

This timing might be fortuitous, if so.
We are about to have the electrician come back to change a few circuits.
As long as he's here, if a load shedding module could be added, maybe we could add a few circuits back in, in case of extended use.

Mouses... the sound within the house (with ancient single pane windows, NO soundproofing anywhere, and we suspect just about no insulation, unfortunately) is much *less* than those noisy leaf blowers, which are much, much more annoying throughout the entire house, regardless of where they are being used, even by neighbors.
If we are right next to the generator, inside, yes, it's a bit noisy, but still not like those leaf blowers.
Anywhere else in the house, barely noticeable.
Any well insulated home would presumably have even less noise inside.

Bottom line, we just don't find the noise troublesome, even the few times it was on for hours.
(But keep in mind, we don't find the noise a problem, but others might. For comparison, we *do* find those leaf blowers very annoying!)

RM
I don't see why it couldn't be connected after install. Ours sits right next to the meter and is wired into the main panel which is on the other side of the house from the actual generator. I'm not an electrician, but I can't see why you couldn't just pop open the panel and wire it up after the fact. Here is a link that might be helpful.

http://kohlerpower.com/onlinecatalog/pdf/g6120.pdf

If memory serves, it will control AC units out of the box with no add-ons, but I believe we did have to install one of these inline with the wall ovens to enable them to be shed by the control module.

http://www.kohlergenerators.com/home-ge ... 001-KP1-QS
Bacchus01
Posts: 3182
Joined: Mon Dec 24, 2012 8:35 pm

Re: quiet natural gas generators

Post by Bacchus01 »

lazydavid wrote: Tue Nov 28, 2017 7:25 am They don't need to be inverters, they just have to be (more) expensive. The standard backup generators you see offered (at HD, Costco, etc, along with most home services) use two-pole motors connected to air-cooled engines running at 3600 rpm. These are fairly loud, although good baffling and placement can help somewhat.

Most of the major generator manufacturers (Generac, Kohler, Cummins Onan, etc) also make higher-end units that use four-pole motors connected to water-cooled engines running at 1800 rpm. These are DRAMATICALLY quieter, even before baffling is taken into account. But they use more expensive parts, so they cost more. Ballpark a 20kW unit of the first type will run around $5k (without installation), whereas one of the second type will be more like $8-9k. If you need more than 22kW, you have to go the liquid-cooled route, as that's all that's available.

If you don't want to spend for the higher-end units, my research suggests that the air-cooled Cummins Onan gensets are a little bit quieter than their Generac and Kohler counterparts, due to slightly better baffling design that directs the sound at the ground instead of out the side. But it's likely to be a small difference, 2-3dB at most.
Cummins uses a Chinese engine. I would not recommend
meebers
Posts: 501
Joined: Sat Apr 14, 2012 7:20 pm
Location: Florida

Re: quiet natural gas generators

Post by meebers »

I have NG at my house now. Having used a gasoline generator during the last few hurricanes, it is dooable but slight PITA. . From past experience, gas stations were closed due to no power and/or no fuel in the tanks. I have a neighbor that his house is an assisted living center, and the state has mandated that these type facilities will have backup generators. I have seen several vendors at the house giving quotes, will wait until the dust settles to see what he thinks is the best system/deal. Is there a cost analysis, general average, of the the same load etc of gasoline vrs NG vrs propane?
User avatar
queso
Posts: 1342
Joined: Thu Jan 07, 2016 2:52 pm

Re: quiet natural gas generators

Post by queso »

meebers wrote: Wed Nov 29, 2017 8:57 pm I have NG at my house now. Having used a gasoline generator during the last few hurricanes, it is dooable but slight PITA. . From past experience, gas stations were closed due to no power and/or no fuel in the tanks. I have a neighbor that his house is an assisted living center, and the state has mandated that these type facilities will have backup generators. I have seen several vendors at the house giving quotes, will wait until the dust settles to see what he thinks is the best system/deal. Is there a cost analysis, general average, of the the same load etc of gasoline vrs NG vrs propane?
I have a gas portable too. It was my only generator before we bought the whole house generator. It works great and with a little creative extension cord management I can keep both freezers from melting and run a few items as well. I got around the gasoline issue by storing several 5 gallon gas cans all treated with Stabil and labeled by date. I'd use them in my lawn equipment and if they got too old just dump them in one of the cars and then go refill them. As you point out, you don't want to be scurrying around when a big storm is about to hit trying to fill up all your gas cans. You need to be prepared ahead of time. It's a bit of a hassle dealing with all that gasoline, but you can manage it if you come up with a system. Depending on the size/capacity of your generator you will also need to man it to keep it from running out of fuel. Again, doable, but a pain compared to a whole house generator.
Topic Author
mouses
Posts: 4217
Joined: Sat Oct 24, 2015 12:24 am

Re: quiet natural gas generators

Post by mouses »

The reason I'm looking at a whole house generator instead of a portable is that, as an older person, I want it to be effort-free. I don't want to be outside in the wind and snow drifts carting gasoline between the garage and the generator and worrying about running out of gasoline, which seems a real possibility with the multi-day power outages we've had in the recent past years. As one gets older, a lot of stuff becomes less simple to do, sigh.
glock19
Posts: 202
Joined: Thu May 03, 2012 9:49 pm

Re: quiet natural gas generators

Post by glock19 »

mouses wrote: Thu Nov 30, 2017 9:05 am The reason I'm looking at a whole house generator instead of a portable is that, as an older person, I want it to be effort-free. I don't want to be outside in the wind and snow drifts carting gasoline between the garage and the generator and worrying about running out of gasoline, which seems a real possibility with the multi-day power outages we've had in the recent past years. As one gets older, a lot of stuff becomes less simple to do, sigh.
I am currently in the process of installing a 24kw Generac for the same reasons as you. I have been using a 8.5kw portable powered by NG for many years and it does a fine job except for running A/C units. I'm just getting to the point in years that I'm not really crazy about getting up in the middle of the night and hooking up the portable.

You have got lots of good comments and ideas in this thread. I am doing the project myself and while there is a lot of preparation, it's not overwhelming. Calculating your power requirements for your house is important, but in the end, a 20 or 22 kw is as large as you can go without getting into water cooled generators. Unless you are only considering doing a few circuits, go ahead with the largest air cooled unit and it will be fine. Most whole house transfer switches come with load shedding modules, or they can be added. Remember, in most outages you are not going to be running all of you electrical appliances, only the important ones.
jasc15
Posts: 419
Joined: Wed Dec 19, 2012 12:36 pm

Re: quiet natural gas generators

Post by jasc15 »

I remember in 2004 or 2005 hearing coworkers talking about investing in a company that made small natural gas turbine generators that were about the size of a refrigerator. I thought the name was Keystone, but apparently there is a company called Capstone that makes what I was remembering. Turns out the smallest one they make is 30 kW, so not for residential use.

https://www.capstoneturbine.com/products/c30

Maybe there are other turbine products for residential use.
Ron
Posts: 6972
Joined: Fri Feb 23, 2007 6:46 pm
Location: Allentown–Bethlehem–Easton, PA-NJ Metropolitan Statistical Area

Re: quiet natural gas generators

Post by Ron »

We had our 20KW Generac installed in the spring of 2013 by our HVAC contractor, who sells/installs/maintain both the Generac and Kohler brands with no "push" to install one over the other. We went with the Generac primarily due to market penetration when compared to the other brands. While one of the main difference is that Kohler has hydraulic valve lifters over the Generac's solid lifters, the Generac only required an initial adjustment during the first annual maintenance cycle, and it has run well over the last 3.5 years with no unscheduled outages - both during the weekly exercise and the various outages we've experienced.

Of the eight home backup units installed within a block of my house, seven are Generac's and one is a Kohler, FWIW.

During the pre-install work, we defined what circuits would be covered and in what sequence would the load sheading modules (wired in-line to the various 220v circuits) operate. The transfer switch has a built in circuit control for up to two heating/cooling devices. Since our home is total electric, using only one heat pump for heating/cooling, we only needed one contact control. The other is still available if we ever want/need to go to a split system if we add on to our home.

The other four controlled circuits using PMM's (ref: https://r.search.yahoo.com/_ylt=AwrBTza ... .d4ZXtBQ0- ) were put into place in priority sequence as specified by the customer - us. We rated the four 220v circuits in priority sequence:

1. Wall oven/microwave combo (most important)
2. Island cooktop (2nd priority)
3. Electric Clothes dryer (3rd priority)
4. Electric hot water heater (last priority)

The 110v circuits have the priority over all 220v circuits (other than the heat pump). After an outage, the unit will start up and return 110v circuits within 20 seconds (10 second wait for electric utility to do a possible switch over, 5 seconds after that for the generator to crank up, five seconds later, for the unit to stabilize output and the transfer switch to move power from the utility to the generator).

The heat pump (heating or cooling) will come on line as a priority. Each of the four controlled circuits will come on line (in sequence) after a few minute delay in order for them not to overload the system. If for any reason, the genset is running close to maximum, the lowest priority will not be activated (#4) and go up to #1 as the need arises.

Some families would rate the hot water heater as more important than the clothes dryer. However, in our home there is only the two of us and the water heater is more than adequate to take care of our needs without quickly running out of hot water. It's really up to you to specify what's most important.

We have two circuits locked out and will not come on when the generator is running. They are the heat pump's backup aux heat (strip) and the four electric strip heaters we have on each of our four walls in our unfinished basement. The heat pump aux heating strip rarely comes on and if it was wired in, would probably draw most of the 85 amps being generated (75 amps on NG). Ours is around 85 amps due to using propane as our gas source (using a 500 gal underground tank).

The electric strip heaters on the basement walls are just there to keep the basement at a minimal temperature during the winter - about 55 degrees. They certainly would not be needed during an outage.

BTW, concerning the noise level. Our unit has an automotive type muffler that the two exhaust ports feed. When it's running, we hear a low hum - nothing else. In fact, the first time we lost power we didn't even know it except for the bedside clock display was off. I thought it was broken since the rest of the power in the house was normal. It wasn't until I finally heard the genset running. Of course, our bedroom is in the front of our house on one end, and the genset is at the other end of the house in the back by our attached garage. I guess location is an important consideration during the planning phase, along with managing the system loads.

Just some more "stuff" to add to the thread, since we've gone through this in the past.

- Ron
iamlucky13
Posts: 3527
Joined: Sat Mar 04, 2017 4:28 pm
Location: Western Washington

Re: quiet natural gas generators

Post by iamlucky13 »

jasc15 wrote: Thu Nov 30, 2017 1:38 pm I remember in 2004 or 2005 hearing coworkers talking about investing in a company that made small natural gas turbine generators that were about the size of a refrigerator. I thought the name was Keystone, but apparently there is a company called Capstone that makes what I was remembering. Turns out the smallest one they make is 30 kW, so not for residential use.

https://www.capstoneturbine.com/products/c30

Maybe there are other turbine products for residential use.
Turbines are generally most cost effective in high utilization scenarios, and those Capstone turbines in particular are intended for applications where there is a use for the waste heat they produce. They have several case studies on that site reflecting this, such as a dairy farm burning methane produced from their manure to produce some electricity and heat their barns.

Even powerplants up to several hundred MW are often built with reciprocating engines if the intended use is intermittent load balancing, because of the low initial cost and relatively easy start up.
ncbill
Posts: 2053
Joined: Sun Jul 06, 2008 4:03 pm
Location: Western NC

Re: quiet natural gas generators

Post by ncbill »

Ron wrote: Thu Nov 30, 2017 1:52 pm We had our 20KW Generac installed in the spring of 2013 by our HVAC contractor, who sells/installs/maintain both the Generac and Kohler brands with no "push" to install one over the other. We went with the Generac primarily due to market penetration when compared to the other brands. While one of the main difference is that Kohler has hydraulic valve lifters over the Generac's solid lifters, the Generac only required an initial adjustment during the first annual maintenance cycle, and it has run well over the last 3.5 years with no unscheduled outages - both during the weekly exercise and the various outages we've experienced.

Of the eight home backup units installed within a block of my house, seven are Generac's and one is a Kohler, FWIW.

During the pre-install work, we defined what circuits would be covered and in what sequence would the load sheading modules (wired in-line to the various 220v circuits) operate. The transfer switch has a built in circuit control for up to two heating/cooling devices. Since our home is total electric, using only one heat pump for heating/cooling, we only needed one contact control. The other is still available if we ever want/need to go to a split system if we add on to our home.

The other four controlled circuits using PMM's (ref: https://r.search.yahoo.com/_ylt=AwrBTza ... .d4ZXtBQ0- ) were put into place in priority sequence as specified by the customer - us. We rated the four 220v circuits in priority sequence:

1. Wall oven/microwave combo (most important)
2. Island cooktop (2nd priority)
3. Electric Clothes dryer (3rd priority)
4. Electric hot water heater (last priority)

The 110v circuits have the priority over all 220v circuits (other than the heat pump). After an outage, the unit will start up and return 110v circuits within 20 seconds (10 second wait for electric utility to do a possible switch over, 5 seconds after that for the generator to crank up, five seconds later, for the unit to stabilize output and the transfer switch to move power from the utility to the generator).

The heat pump (heating or cooling) will come on line as a priority. Each of the four controlled circuits will come on line (in sequence) after a few minute delay in order for them not to overload the system. If for any reason, the genset is running close to maximum, the lowest priority will not be activated (#4) and go up to #1 as the need arises.

Some families would rate the hot water heater as more important than the clothes dryer. However, in our home there is only the two of us and the water heater is more than adequate to take care of our needs without quickly running out of hot water. It's really up to you to specify what's most important.

We have two circuits locked out and will not come on when the generator is running. They are the heat pump's backup aux heat (strip) and the four electric strip heaters we have on each of our four walls in our unfinished basement. The heat pump aux heating strip rarely comes on and if it was wired in, would probably draw most of the 85 amps being generated (75 amps on NG). Ours is around 85 amps due to using propane as our gas source (using a 500 gal underground tank).

The electric strip heaters on the basement walls are just there to keep the basement at a minimal temperature during the winter - about 55 degrees. They certainly would not be needed during an outage.

BTW, concerning the noise level. Our unit has an automotive type muffler that the two exhaust ports feed. When it's running, we hear a low hum - nothing else. In fact, the first time we lost power we didn't even know it except for the bedside clock display was off. I thought it was broken since the rest of the power in the house was normal. It wasn't until I finally heard the genset running. Of course, our bedroom is in the front of our house on one end, and the genset is at the other end of the house in the back by our attached garage. I guess location is an important consideration during the planning phase, along with managing the system loads.

Just some more "stuff" to add to the thread, since we've gone through this in the past.

- Ron
Ever thought about changing out your air handler (heat strips) for one with a gas furnace as backup?

In an extended outage you'd go through a lot less propane burning it directly versus running a generator to run the heat pump's compressor.
Ron
Posts: 6972
Joined: Fri Feb 23, 2007 6:46 pm
Location: Allentown–Bethlehem–Easton, PA-NJ Metropolitan Statistical Area

Re: quiet natural gas generators

Post by Ron »

ncbill wrote: Fri Dec 01, 2017 9:31 pm<snip...> Ever thought about changing out your air handler (heat strips) for one with a gas furnace as backup?

In an extended outage you'd go through a lot less propane burning it directly versus running a generator to run the heat pump's compressor.
First of all, there is no NG in our area. To run a split unit, a few folks have put in an oil fired unit to work with the HP in order to supply emergency heat rather than the electric heat strips on the air handler.

In other areas of the country where a heat pump may be in place that uses supplemental heating (regardless of fuel source) extensively? Then yes, I could see the advantage. However, where we live, the emergency heating (air handler heat strip) comes on rarely during the winter heating system.

If we were in an area that used the supplemental (emergency) heat quite often, we would have already installed a split system to save in electricity costs, years ago (we had our home built 20+ years ago).

- Ron
Post Reply