External Generator size/output

KevinjmAZ · 08-07-2023, 12:38 PM

I have a 2019 Outlook 27D Class C Motorhome. I do have an onboard generator but like to have a seperate when camping to elimate noise. What size do I need to run AC or Heat?

Thanks

Kevin

BobC · 08-07-2023, 01:02 PM

By heat, do you mean your onboard propane heater or a supplemental, electric heater? The onboard heater won't put much of a load on a generator but a supplemental, electric heater will consume 1200W - 1500W (or more) depending on the heater.

A/C can be a challenge and, depending on the specs of your A/C, you could need 3500W or more. This means big, heavy and expensive. Rather than buy a heavy generator, some choose to go with two, smaller 2000W - 2200W generators and "parallel" them. Honda and some other brands allow this. Whatever you do, don't be tempted to get an "open frame" generator. They're inexpensive but very noisy.

In terms of dBs, I'm not sure how much quieter this is going to be than your onboard generator but the portables can be located away from your MH. This reduces the noise you hear but they're still going sound noisy or maybe even noisier to your neighbors.

KevinjmAZ · 08-07-2023, 02:27 PM

Thanks, Yes more interested in the AC side of things. I know the noise level would be similat but at least away from the unit and not vibrating under my feet.

BobC · 08-07-2023, 03:00 PM

If you're not on a tight budget, I'd recommend two Honda EU2200i generators which are pretty much considered the gold standard. They are, however, running about $1,299. There are other, much less expensive contenders but I'm not familiar enough to recommend one.

Here are ten pages worth of postings on IRV2 on this subject:

https://www.irv2.com/forums/f59/gens...0i-569060.html

If, by any chance your A/C will run on only one Honda 2200i, I'd definitely recommend it, but two gets pretty pricey.

Ray,IN · 08-07-2023, 06:24 PM

Quote:

Originally Posted by BobC

If you're not on a tight budget, I'd recommend two Honda EU2200i generators which are pretty much considered the gold standard. They are, however, running about $1,299. There are other, much less expensive contenders but I'm not familiar enough to recommend one.

Here are ten pages worth of postings on IRV2 on this subject:

https://www.irv2.com/forums/f59/gens...0i-569060.html

If, by any chance your A/C will run on only one Honda 2200i, I'd definitely recommend it, but two gets pretty pricey.

**Eagle5** · 08-07-2023, 10:07 PM

Hi Kevin,
My neighbor bought one of these a few months ago:

Champion Power Equipment 200954 4250-Watt RV Ready Open Frame Inverter Generator, Quiet Technology

At $468, it is an option to consider. It is quieter than the 4,000 watt Onans which are built into our 2019 Class Cs. Also, because it is an Inverter Generator, it will rev slowly when the electrical load is low, and slower RPMs means quieter.
Eagle5

Marine359 · 08-08-2023, 08:37 AM

With a Class C, you don’t have much storage, so it would be a PITA to get a big generator, like a 3,500w or larger. $250 is well spent on a soft start which reduces the start up amperage of the AC compressor sufficiently to be able to run it off a small quiet portable inverter/generator. Any 2500w generator will then be able to get the job done. Of course I prefer a dual fuel model that can be run on propane. A dual fuel and soft start will cost combined less than a single Honda EU2200. Yes, Honda is the gold standard, but are you willing to pay over $1,000 for a generator that is a bit quieter than all others, or is the sound of a dual fuel quiet enough? Remember, if you get a gasoline only generator, you’ll also have to haul around a refueling tank, and deal with the messiness and odors. You already have propane onboard you can tap into. A 20# propane tank will run a dual fuel for 30 hours.

Ray,IN · 08-09-2023, 07:04 PM

Quote:

Originally Posted by Eagle5

Hi Kevin,
My neighbor bought one of these a few months ago:

Champion Power Equipment 200954 4250-Watt RV Ready Open Frame Inverter Generator, Quiet Technology

At $468, it is an option to consider. It is quieter than the 4,000 watt Onans which are built into our 2019 Class Cs. Also, because it is an Inverter Generator, it will rev slowly when the electrical load is low, and slower RPMs means quieter.
Eagle5

Download a dba meter app onto your phone and measure both of those gensets.

The specs state the noise level is 64dba @ 23ft. from genset. That is not quiet. What bothers other campers most is the constant droning sound of a genset, the dba level increases that annoyance.

BobC · 08-09-2023, 07:41 PM

The Honda 2200i is rated at 57dBA at full load, 48 at 1/4 load. Since an increase of 3dB represents a doubling of the sound level, 63dBA is four times as loud as 57dBA. This is one dBA less than the Champion 4250 at 64dBA. Plus, Champion doesn't say this is at full load. My understanding of dBA is that they're not additive, two Hondas aren't going to be any louder in terms of dBA than one.

Honda doesn't make a comparable generator but their EU3200i and their EU7000iS are rated at 58dBA at full load.

Now, some are going to chime in with comments about perceived sound differences being less than this, nonetheless, 64dBA isn't just a little louder, it's a lot louder. It also makes a big difference which way the exhaust is pointed so, regardless of what you have, don't point it at your neighbors.

Marine359 · 08-10-2023, 03:13 PM

Bob,
I don’t think anybody with a brain cell working will challenge you about how much quieter Honda generators are versus other small inverter/generators. The real issue is, what is the real difference in real world camping?

In NF, NP, and SP where there are established generator hours, everybody is running their generators at the same time. My experience in these campgrounds is that it would take a very well trained ear to determine who is running a Honda and who isn’t. Just doesn’t make a hill of beans worth of difference unless somebody is running an open frame generator, which is way way louder than all others.

In BLM dispersed, I’ve never been able to say to myself: my neighbor there 200 yards away, must be running a Honda, because I can barely hear it. C’mon man. That just doesn’t happen.

So when is it really advantageous to run a generator slightly quieter than everybody else’s generator. NEVER!

If you want quiet, buy more solar and bigger batteries. Camp in dispersed more than 200 yards away from the closest neighbor and go for days with no generator at all.

crumjack · 08-13-2023, 08:00 PM

FWIW, we have a Champion 2500 dual fuel that we run on propane. The discussion on generator noise had me curious so I checked it this weekend with decibel meter app. At about 25 feet, about 70 decibels. At about 50 feet with the camper (MM 2108) in between read around 60 dbs.

Just sharing for reference.