Small diesel generator?

The smallest they seem to have is a 3.5 Kva and it is a bit heavy. I know they go well in boats but it would be hard to fit in. I am being picky but am trying to find something not too different to the Honda 2KVa in noise & weight - a big ask.
thanks

Shaker,
I spent a lot of time with Mr Google but did not see the small Yanmar. Have now looked directly and it is probably the best bet so far but is much noisier and heavier than I would like. My benchmark is the Honda 2 & 3 KVa and the Yanmar is way above. I know I am being picky.

thanks for the suggestion.

cheers

I had a Yanmar 2.2 for 10 years and it is heavy and noisy, but it was quality. IMHO far superior to my Honda, It just feels like it would last for 50 years.

Cheers Wilko

Ross,
Cost I would think although I will look as this is not an option I had considered.
thanks

Ross,
I am very wary of the stuff that Bunnings sells. I will look into it though as I hope it will not be used much. Noise is the big factor from my point of view.
thanks

Ross,
The only one Bunnings have now is a 4.5KVa Kipor which weighs in at 177Kg !!

Still I will look at Kipor further and perhaps Bunnings had something smaller.

cheers

Barry,
Yes the Yanmar looks to be the best fit but it is heavy and noisy.

On the basis of cost, noise, weight and performance I think I am going to fail on my diesel only wish and probably end up with a Honda and a jerry can !!!

Still I have plenty of time to keep looking.

thanks
alastair

Alistair,

Agree with Bob re the Kubota range if you want quiet and smooth (minimal vibration). I think their smallest is as Bob has said about 5kva with a 2 cylinder diesel. Unfortunately any diesel is going to be more expensive and heavy compared with a petrol unit.

Cheers
Pop

GT,
yes it will probably be built using a steel frame and a shell of a sandwich composition fibreglass with a foam centre. The total thickness is ~4cm. I have seen this material and it is both very strong and a good insulator. I had originally thought aluminium was the way to go but have changed after having considered various options.
cheers

Mh,
A quick look at the website only shows units larger than I need.

I think I have to accept that the mass produced petrol generators are the way to go on cost, size, noise and reliability.

That company has other things of interest so thank you.

cheers

Keith,
A quick look at the specs for say a 1HP domestic ac unit (750W) suggests that they draw about 1000w when operating. Given the ~90% efficiency of an inverter this means nearly 100A operating. Assume 50% duty cycle and 8 hrs running equates to 400AH. So that the batteries only go to 50% discharge I would need 800AH capacity. Too much weight and I really doubt the robustness of a domestic a/c on an offroad vehicle.

I will look into Rencool that looks interesting but again the battery capacity since I want to run when stationary.

thanks

Alistair,

I am going through a similar exercise with a little off road caravan that I am trying to build. The consensus on this forum is that domestic split systems hold up very well on caravans and are certainly cheap enough to replace every five years.

Toshiba has a small inverter unit that draws just 260 watts on low setting, which might be enough for a small-ish space. Rencool says that it is commonplace for truckies to run a 12 volt battery aircon to cool truck cab and sleeper overnight.

Lithium iron batteries are always an option, but the dollars are huge. Maybe you could have a low voltage cutout on your inverter which will switch the aircon off before the batteries are damaged. You'd then have the option of getting out of bed and turning the main engine on, or rolling over and going back to sleep. Either way, it will be a hard life for the batteries.

I had a 500cc single banger sea water cooled diesel generator on my boat that ran at a fixed 3,000 rpm. It was a big job to cut down the vibration and and even bigger one to soundproof it properly - with inlet and exhaust air silencers needed to make life bearable. The soundproofing weighed in at about 75 kilos! An air cooled one would be even noisier.

I wonder if running a diesel generator when you're trying to have a kip might drive you crazy. For aircon all day a generator would be the only choice.

Please do a fresh post after you've resolved the issue because I, for one, am really interested in how you get on.
Good Luck!

Keith

Keith,
Yes I will post a new thread if I solve the issue in an interesting way but currently I doubt it.

This vehicle will be for offroad touring and initially I was not going to have an a/c or generator. Since I will be spending a fair bit of money and our trips will be of reasonable duration, often months, and sometimes in humid conditions, I was told that we should include a/c for comfort reasons. I agreed rather than have a dispute in the planning phase.

We are travellers not stayers - by this I mean we do not tend to stop for many days in one place so daytime a/c is not an issue as it will be provided by the cabin a/c whilst travelling. Even now we rarely put the a/c on unless the conditions are really bad. If we were stayers I would be buying a caravan to tow behind the existing Landcruiser rather than going down the route I am.

Since we travel in remote areas and overseas I want reliability, minimum weight and space and standard units that are most likely to be supported away from home base. If the a/c or generator breakdown then I will not see it as a major problem as I will not be dependent on them.

At the moment for all the above reasons I expect I will go for a Dometic roof a/c and a Honda 2KVA petrol generator. This will meet the operation requirements and keep the cost down.

I thought I had come across something possible in the form of a Nanni diesel 3.5KVA generator with electric start and low noise figures. It was heavy but I thought it was not impossible. Unfortunately when I read the specs properly it was designed for seawater cooling !!!

Whilst I respect the experiences of people who have used domestic a/c units I just don't believe they would stand up on some of the roads I have travelled on and also they would take up a lot more space.

I will let you know what my final decision is. It will probably be about 12 months before the fitting out decisions will be actioned.

cheers

Alistair,

I think you've made the right decision as there's a certain attractive KISS principle to it.

I have also decided on a 2kVa Honda, but will go with a new domestic (not Dometic) spit system aircon unit every five years - largely for quietness. The hard bit is keeping the gennie whisper quiet, around other campers.

So the plan is to put the Honda into an acoustic enclosure and feed the fuel via a remote tank directly into the carbie. There will be two 12V four inch centrigual blowers with a silenced intake and an air outlet that mixes the outgoing air with the exhaust to cool it down, again through a silencer made from ceramic wool.

I am thinking about putting in a temperature triggered extinguisher and a solenoid valve that will simultaneously shut the fuel off in the event of fire.

I hate noise in the bush, but I'd love to meet up with you on the track some day. Good luck with your adventure. We're all green with envy.

All the best,
Keith (lapsed engineer)

Keith,
Yes KISS is a principle that should guide most designs.

In that regard I think you should simplify your own design. The amount of heat 'generated' by even a small generator like the Honda 2KVA is quite substantial, especially when under load. With the fans, sensors, shut off valves etc you are proposing I see not only significant cost but scope for problems.

I will have the generator in a side locker, fully lined with sound absorbent material, with a flap door that hinges at the top and a gas strut so that it acts like a sloping roof. I will have the generator on a slide for easy of access but intend that it will operate only partly out but still under the 'roof'. At the outer end of the slide there will be a baffle (easily removed) that is covered on the inner side with sound absorbent material on the inside. The baffle will be made of a dense material to reflect sound back through the absorber.

I used this approach once before to make a sound baffle in front of a noisy external a/c unit. It worked well to quieten it down so the neighbours did not complain.

I will make sure the slide is on vibration mounts as I know that can cause drumming in a rigid structure like I am going to build.

Using this approach the generator can breathe easily and not require forced ventilation. You obviously know what you are doing but I would recommend you simplify your own installation in a similar way.

I will start a new thread down the track when this all turns to expensive reality, hopefully not evaporate.

cheers

Keith,
See my latest post in this thread. Dometic have what I want and they also have petrol versions which may suit you.

These did not show up on a Google search and was only by chance I saw them.

cheers

Derr!!
I just realised that marine gensets have a wet exhaust. So please disregard most of my last post.
Keith