Jeff wrote:
I have a Honda EU2000i and I can say that under load it makes a lot
more noise than the Whispergen. Of course, I didn't hear the
WhispeGen at full load. At low load the Honda is rather quiet, but it
doesn't make heat, hot water, and it won't run unattended.

BTW, both of the pdf's you provide have a noise level; one says 55 dBA
at one meter, (full load implied, though not formally stated), the
other references an ISO standard which is 50 dBA at 7 meters.

Oh! I see it now. The brochure does say "55dBA" at one meter. That is,
indeed, very quiet. Using an online dB/distance calculator, that means
it would be about 17dB less at the standard measuring distance of 7
meters. Or, in otherwords, the comparison would be 38dBA for the
Whispergen versus 49dBA for the Honda, which is a HUGE difference and
throws a whole new light on the subject.
http://www.mcsquared.com/dbframe.htm

It's seems odd that they wouldn't put the noise figure in the
specification section of their user manual. I did notice the reference
to the ISO standard. However, I wasn't sure that some sort of special
environment wasn't required to obtain that.


a few more comments below ...
wrote:
I always find it very suspicious when a manufacturer advertises the
benefits of their product based on a particular feature and then
doesn't provide a formal specification. As far as I can see WhisperGen
doesn't provide a specification for noise level.

Their brochure, however, does have a graphic that indicates that the
noise level falls between normal conversation at 60db and a
refrigerator at 50 db. So, I guess we can assume the noise level is
about 55 db(A) and is measured using standard industry techniques.

Some applicable specifications for a Honda EU3000is, for instance, a

58 dB @ rated load (2800W)
49 dB @ 1/4 load (700W)
Fuel Tank Capacity: 3.4 gallons (12.9 liters)
Run Time on one tankful: 7.2hrs @ rated load; 20hrs @ 1/4 load
Liters per hour: 1.8 @ rated load; 0.65 @ 1/4 load
Dry Weight: 134 lbs

So, it looks to me like the Honda EU3000is is actually a lot quieter
than the WhisperGen when it is operated at an equivalent wattage output
and has roughly the same noise level when operated at 3 1/2 times more
power than the WhisperGen.

58 dba is not "roughly the same" as 55 on a logarithmic scale.

It true that 58 dBA is not "roughly the same" as 55dBA, but at the time
I wasn't sure that the WhisperGen wasn't louder than 55dBA. For the
purposes of human perception, I believe the rule(s) is as follows:

"1 dB is generally the smallest difference that can be perceived by
human beings
A 3 dB difference is clearly audible for just about anyone with normal
hearing
A 10 dB difference is generally perceived as being twice or half as
loud."



Also, assuming I've done the calculations correctly, the EU3000is is
probably more fuel efficient since it only uses about 0.65 liters per
hour at 700W while the WhisperGen uses "Less than 1 litre per hour".

Again, you have to add in the heat and hot water. It also says ".75
liters/hour at max output"


The Honda EU3000is, incidentally, costs about $2000.00.

Yup. No argument on that front. However, the Whispergen is built for
100% duty cycle, doesn't need oil or oil filters, etc. It comes with
electronic controls for monitoring temp and battery levels, etc. As I
said, this is much different from a portable genset.

That's true.




http://www.whispergen.com/content/li...t_Brochure.pdf

http://www.whispergen.com/content/li...ers_Manual.pdf
http://www.hondapowerequipment.com/M...lName=eu3000is

Jeff wrote:
These are a different beast - because they are "external combustion"
(like a house furnace) they are very efficient and can be set to run
unattended, so they claim. Also, they are extremely quiet. I stood
next to one at the show and could barely hear it running. Also, I
could hold the exhaust flew in my hand (briefly). I can see an
situation where it would fit in nicely. However, for my purposes, I
can see better uses for $12K.


Scotty wrote:
$12 k !!!! Holy ****! You could buy a dozen Honda gens
for that.

SBV


"Bart" wrote in message
ups.com...
I have a chance to see a DC WhisperGen at the
Norwalk Boat Show today. I was very impressed.

The price was $12k. It provided 800 watts of power,
70 amps at 12 Volts for 1/5 gal per hour or about
.75 ltrs/hr.

It provided heat for hot water and was efficent enough
such that the exhaust was comfortable to touch.

Most impressive was the quiet sound it made--quieter
than a small window AC unit. With the sound cover
on it was difficult to hear.

Until noisy diesel gensets that are so annoying, this
unit can be set up to start when needed and was
quiet enough not to be a nuisance when running.

If agumented with solar cells, or even a wind generator,
I think the daily fuel consumption would be quite low.

So anyone considering a new genset, and/or heater, and
possibly AC for their boat, this with a good battery bank
would make a nice system.