Review Date:  2004.06.22

 

REVIEWER INFORMATION
Name:  Thomas Lindemuth
Age:  39
Gender:  Male
Height:  5 ft 10 in (178 cm)
Weight:  195 lbs (88 kg)
Email address:  tlindemu(at)ix(dot)netcom(dot)com
Location:  Oakland, California  USA

 

Backpacking experience:  I've camped my whole life, and backpacked occasionally starting at age 12.  After a break of several years, I've picked it up again starting about three years ago, and I am currently introducing my sons to the joys of camping.  When not backpacking I greatly enjoy day hikes, and make a regular practice of hiking the trails that are accessible near my home.  I prefer backpacking, but will occasionally car camp.  I probably would be classified as a heavyweight backpacker, but I am experimenting with ways of lightening my load; I don't expect to go hardcore ultralight, but I've dropped nearly ten pounds off my base weight.  I generally camp in the mountainous regions of California; I prefer trees and water, generally speaking.  I am a destination backpacker, not a through-hiker (I don't currently have time for extended trips).  I enjoy hiking in, setting up base camp for a few days, and exploring what is nearby.

 

PRODUCT DESCRIPTION
Product Name:  Optimus NOVA Multifuel Expedition Stove
Year of manufacture:  2003
Manufacturer:  Optimus International
URL:  http://www.optimus.se

 

 

Size (manufacturer's spec):
o  none provided from manual or manufacturer's website
Size (measured as delivered):
o  Stove, packed in case: 6 in (15 cm) x 4.5 in (11.4 cm) x 3.3 in (8.4 cm)
o  Stove, unfolded:  6 in (15 cm) Dia x 3.5 in (8.9 cm) H (plus valve and fuel bottle)
o  Fuel bottle, with pump:  2.9 in (7.4 cm) Dia x 8.3 in (21.1 cm) H
o  Fuel line, length:  9.5 in (24.1 cm)

 

Weight (manufacturer's spec):
o  14.8 oz (420 g) (includes fuel line and pump, excludes fuel bottle)
o  weights of other items not specified
Weight (measured as delivered):
o  Stove:  15.0 oz (425 g) (includes fuel line and pump, excludes fuel bottle)
o  Fuel bottle:  3.8 oz (91 g)
o  Maintenance Tool:  1.2 oz (34 g)
o  Carry case:   1.6 oz (45 g) (includes spare O-ring set)
o  Auxiliary Fuel Cap:  0.6 oz (17 g)

 

Fuel Bottle Capacity (manufacturer's spec):
o  Absolute Capacity 20.3 oz (0.6 L)
o  Working Capacity 15.5 oz (0.45 L)

 

Fuels (manufacturer's spec):
o  Naphtha (Coleman fuel), Kerosene/paraffin, white gasoline/petrol, diesel #1, rape seed (colza) fuel and similar fuel types.

 

Burn time per fill (manufacturer's spec):
o  Up to 2.5 hours at high output

 

Heat Output (manufacturer's spec):
o  Approx. 2,850 Watts/9,700 BTU

 

Accessories supplied with stove:
o  Nylon carry case
o  Maintenance multi-tool
o  Replacement O-rings and inline fuel filter
o  Auxiliary fuel bottle stopper
o  Instruction sheet

 

MSRP: $149 US 

 

 

Optimus stoves are apparently now marketed by Brunton, so the packaging and the fuel bottle now say Brunton in big letters.  However, the stove is indeed still made by Optimus.  Other than that, there wasn't anything particularly remarkable about the packaging of the Nova, so I'll spare you the details, other than to note that everything was present and intact when I got it home.

 

The stove package includes the following: the stove itself, with valve and fuel line attached; pressurization pump; 20.3 ounce (0.6 liter) fuel bottle; auxiliary fuel bottle stopper; nylon carry case with hook-and-loop closure and belt loops; maintenance multi-tool; spare O-rings and fuel line filter; instructions.

 

The instruction manual is a fold-out sheet of paper.  It has good, simple, straightforward operating and maintenance instructions, appropriate safety warnings, and a diagram of how to disassemble the stove.  I have mislaid my copy sometime during the last few months; however, Brunton makes the manual available on their website in PDF format. Optimus, on the other hand, does not.

 

This stove has the most elegant physical design of any liquid fuel model that I've seen.  The legs are curved, so that when folded, they fit tight against the burner bowl; this makes for a very compact package when stowed.  When extended, the legs create a tripod with a diameter of approximately 6 inches (15 centimeters).  The tops of the legs, which form the pot stand, are serrated to provide extra traction on the bottom of the pot.  I spent a considerable amount of time in the stove aisle at REI, playing with the various models, and the Nova felt the most stable, both the stove itself and how the pot sat on it.

 

One of my dreads before buying a liquid fuel stove concerned priming. I've seen one or two other models of liquid fuel backpacking stove being primed, and it's not a pretty sight: a dollop of raw fuel spilled into a priming cup (and if one isn't careful, everywhere else); a minute or more of billowing orange flames before the stove finally runs properly; and at the end, soot all over the stove and anything that touches it thereafter.

 

So I approached the first lighting with some trepidation...and was pleasantly surprised!  The Nova is incredibly easy, fast, and clean to prime -- on a miniscule amount of fuel, and it's ready to go in 30 seconds, give or take a few.  The process is quite simple:  make sure the burner valve is turned off; pressurize the fuel bottle with 20 to 25 strokes of the pump; turn on the fuel valve for a count of two seconds, then immediately shut it off; and light.  The priming flames, which usually rise to no more than 10 inches (25 centimeters) or so, subside in 20 to 30 seconds, at which point the fuel valve is opened (carefully) again, and the stove roars to life.  And there is virtually no soot created by the process.  (The one time where I did get a lot of soot was when I forgot to turn the fuel valve off at the beginning of the process, thereby accidentally spilling way too much priming fuel.  It taught me to not be careless, and the problem has not recurred.)  It's not as easy as lighting a propane stove, but it's hardly what I would call a hassle.

 

Once the stove is going, it is practically as easy to use as the kitchen range at home. (Well, if one's kitchen requires one to squat over one's range on the ground, and balance one's plate on a log, anyway.)  After priming is done, the heat output can be increased with another 15 or so strokes on the pump.  The rated heat output is 9,700 BTUs, which is not the highest among backpacking stoves, but it is more than enough to carbonize any meal I might care to leave on it, were I to get distracted for a few minutes.  Luckily, such an outcome is anything but preordained, because the flame can be adjusted anywhere from an intimidating jet engine blast down to a tame blue trickle.  The control valve is on the burner body, not the fuel bottle, so adjustments take effect immediately.  The adjustment handle for the fuel valve folds out away from the stove, so fingers are kept well away from the flame.  The adjustment handle sports a diagram, stamped into the metal, to indicate the respective directions to turn for 'low' and 'high.'

 

It does run a bit loud, though not what I would call objectionably so, and this is apparently common to many liquid fuel burner designs. Admittedly, my standard for quiet is an alcohol burner, which is all but silent -- a tough bar to meet.  A fair comparison of the noise level might be a propane brazing torch -- not silent, but not deafening either.  For specifics, see "Kitchen Tests" below.

 

Turning the stove off is done by flipping the fuel bottle over.  This causes the fuel intake line inside the bottle to stick up out of the fuel, and the pressure in the fuel bottle then purges the fuel line in about a minute, at which point the flame goes out with a gentle hiss.  This means that when it is time to pack up, there is no fuel in the line, and no pressure in the bottle, so no spillage when disconnecting the fuel bottle from the stove.  I find this to be very nice.  Note that the stove can also be turned off for brief periods (very brief; see "Concerns" below) simply by closing the fuel valve.

 

The stove can be stowed in its nylon carry case.  The fuel bottle comes with a separate screw-cap, but the manual suggests simply leaving the pressure pump installed on the bottle while traveling.  The pump has an inline quick-connect valve for the fuel line connection.  This quick-connect shuts off when the fuel line is removed, which prevents fuel from spilling during disconnection.  A plastic cap to keep dirt out of the fuel connector is also supplied, and attaches to the pump body with a plastic strap, so it won't get lost.

 

This stove purports to run on a variety of liquid fuels.  I have not tried anything other than naphtha (aka Coleman) fuel.  Personally, I don't anticipate going anywhere that Coleman fuel can't be had, but for those who are heading somewhere more exotic, where one might have to cook on, for example, diesel, the Nova supposedly will burn it.  (This was nonetheless an attractive feature to me.  I'm a sucker for industrial-strength tools.)  One interesting tidbit for tech-heads is that the Nova uses the same fuel nozzle for all fuel types.  Many other stoves require a specific nozzle to be installed when changing fuels. 

 

The fuel bottle size is 20.3 ounces (0.6 liters). However, the bottle must be kept partially empty to allow air space for pressurization, thus the working fill capacity is 15.5 ounces (0.45 liters).  Optimus makes a larger fuel bottle as well, sold separately.  The larger bottle has an absolute capacity of 34 ounces (1.0 liters) or a working capacity of 26 ounces (0.75 liters).

 

The stove has an interesting arrangement for cleaning out the nozzle in the event of a clog.  The cleaning needle is inside the nozzle, and is activated by waving a magnet (on the multi-tool) under the stove.  This raises the cleaning needle up through the jet, and pushes the clog out, rather than in.  The action is similar to a shaker jet, without having to actually pick it up and shake it.  Cleaning can even be done while the stove is running.  I have not had any problems with the stove clogging up so far, but the mechanism to deal with it appears to be a good one.  The manual recommends cleaning the jet before lighting as a matter of routine, which I do.

 

 

Boil Time:
I've done the obligatory time-to-boil tests.  My preference usually is to boil a quart (liter) at a time, rather than two cups (half a liter), because I camp with multiple people, and it is very easy to run through that much hot water making cocoa or coffee, or cleaning up a whole meal, for three.

 

Optimus claims a boil time for 1 liter of water of "down to 3.5 minutes (varies with fuel, climate, altitude, fuel bottle pressure etc.)."  I was not seeing times as good as that, but I wasn't too concerned, because it performed every bit as well as my kitchen range, using the same stainless steel backpacking cookpot.  The details follow:

 

Water temperature:  68 F (20 C) from the tap, as cold as it would run
Ambient air temperature: 68 F (20 C)
Wind:  slight (vent hood going, to draw exhaust gases out of the kitchen)
Pot:  1.3 quart (1.2 liter) stainless steel, thin-walled pot with cover

 

My method was as follows:
1)  Run the tap to achieve lowest temperature in the pipes;
2)  Measure water into a 1 quart (0.95 liters) mason jar and thence into the pot;
3)  Light the stove, priming if necessary;
4)  When the stove was running properly, place the covered pot on the stove and start timing;
5)  Record times to reach various temperatures up to 212 F (100 C) as measured by a thermometer stuck through the screw hole for the lid handle, which I had removed for the test;
6)  Empty contents and cool the pot down again by running it under the tap, then repeat the procedure.

 

The average times to the various temperatures were:
o  120 F (49 C):  2:25
o  150 F (66 C):  3:45
o  180 F (82 C):  5:10
o  212 F (100 C):  6:15

 

Note, these times do not include the priming time.  Note also that times were 10 to 15 seconds faster with a 3-sided aluminum windscreen surrounding the stove.

 

The reason I took various temperatures is that it is not always necessary to bring water to a full boil.  For doing dishes, 120 F (49 C) is plenty hot.  150 F (66 C) is usually good enough for making cocoa (that I don't want my kids to scald themselves on, anyway). There is no reason to waste the time and fuel to bring the water to a full boil for these sorts of things. 

 

Fuel Consumption:
I measured fuel consumption by weighing the fuel bottle before and after bringing a quart of water to boil (or more accurately, letting it run for 6 minutes, since I had done the time-to-boil tests separately).  Six minutes of burn time at full-throttle consumes between 0.5 and 0.6 ounces (14 to 17 grams) of fuel.

 

By way of comparison, cooking breakfast consisting of 8 pancakes (i.e, about 35 minutes at a simmer) consumed 0.7 ounces (23 grams) of fuel total.  Pancakes for four, consuming the same fuel as about 1-1/2 quarts (or liters) of boiled water.  Not bad.

 

I haven't tried to verify the maximum burn time (and don't intend to), though the boil tests seem to bear out that number.  The Nova seems to consume roughly 0.1 ounce (2.8 grams) of fuel per minute at full throttle, so given a full working load of 15.5 ounces (439 grams), that comes out to 155 minutes, or 2 hours, 35 minutes of burn time at full-bore.  (Note that the bottle capacity is in volume, while the fuel consumption is in weight, so that statement is somewhat problematic; but I think it is close enough to serve the purpose here.)

 

Noise Level:
I measured the noise generated by the stove at full throttle and at a low simmer, using a Radio Shack sound level meter held around 18 inches (half a meter) from the stove -- roughly how far away one's ears are while bending over the stove.  At full output, the stove generates a sound level of 68 dB.  At low simmer, the sound level is 64 dB.  If that number looks high, note that the ambient noise level outside (breeze, birds, etc.) was 54 dB.

 

 

The field results are of a more qualitative nature, as I don't bring such unnecessaries as a thermometer or a stopwatch with me on trips.  I'm out there to enjoy nature, not to conduct experiments, and for me the measure of success of a piece of equipment is how well it helps me do what I'm there for.  So, with that disclaimer out of the way....

 

I've been using the Optimus Nova since March 2003.  Aside from camping trips, in the last few months I have made a habit of bringing the Nova along on morning hikes, and making breakfast on the trail:  typically oatmeal or equivalent, a bit of hot ham or turkey, coffee or cocoa, plus enough hot water to rinse everything out before heading home.  I perform this little personal ritual at least once a week.  Never has the Nova failed to light, clogged, or otherwise misbehaved in any way that was not obviously my fault (e.g., forgetting to close the valve before commencing to prime, as mentioned above).  At one point the leather seal cup on the pressurization pump started to slip a bit, but a quick and easy disassembly of the pump shaft and a drop of oil on the leather brought it back into service.  This is well within spec, and is covered in the manual. 

 

Most of my cooking has been done in mild, coastal California weather:  well above freezing, little in the way of wind or other inclement weather.  However, a few specific trips are worth mentioning for weather effects, below.

 

I brought the Nova along on a trip to the Caribou Wilderness (near Mt. Lassen, California) in mid-October. The temperature dropped to around 20 F (-6.6 C) overnight, and in the morning the homebuilt alcohol stove I had also brought along (I'm a stove fiend) wouldn't fire up, because I had failed to keep the alcohol warm.  The Nova, however, didn't seem to notice the cold at all, despite having been left out all night.  (I did give it a 4-second dose of priming fuel, instead of the typical 2 seconds for warm weather, as recommended in the instructions).  This demonstrated to me why white gas stoves are well-suited for cold weather.

 

On another trip I took the family up to Lake Tahoe, California, for a day of snow play, and brought the Nova along to fix hot cocoa.  I carved out a ledge in a snowbank, set a metal dinner plate on that, and set up the stove on the plate, so that it wouldn't melt its way down into the snowbank.  The air temperature was 18 F (-7.7 C) at noon, but the stove started right up, as usual.  I then scooped snow from elsewhere in the snowbank, and started melting it (with a few glugs of liquid water, to get things going).  It took around 15 minutes to go from snow to a quart (liter) or so of boiling water, which included several refills of snow as it melted and the volume was reduced.  I repeated this procedure several times, as several batches of cocoa were called for by the family.  The stove performed flawlessly.

 

A third time I took the stove on an overnighter at Lake Chabot campground (Alameda County, California).  A peculiarity of the weather at that site is that it gets distinctly windy right around sunset.  My father was trying to boil a kettle using a top-mount butane cartridge stove, and having no luck at it.  The wind seemed to be blowing the heat away about as fast as it could come out of the burner.  I had brought a windscreen for my Nova, and it boiled up a pot just fine (though the windscreen did try its best to imitate a kite; I eventually had to weight it down with tent stakes).  The point here is that the Nova burner, being separated from its fuel supply by a comparatively long fuel line, is safe to use within a windscreen (at least not a closely fitted one).  The windscreen I use has only 3 sides, in order to not block access to the adjustment valve; also, being rectangular, it does not enclose the stove and pot tightly, further reducing any risk of overheating. 

 

Aside from plain old boiling water and heating stuff up, I've used the Nova for subtler cooking tasks such as frying pancakes and sausage.  It does great at that too.  The adjustability makes it possible to cook nearly as well as at home.  Well, subject to the limitations of thin-walled backpacking pans, anyway.  My stainless steel backpacking pans cook unevenly even at home, home on the range, as it were, so I bring a thick-walled "home" frypan when I want to cook something where even heating of the pan is important, such as pancakes.

 

 

1:  Turning off and on again may require re-priming. 
There is one last hitch concerning priming, though this is not specific to the Nova.  If a liquid fuel stove is turned off long enough for it to cool somewhat, it will reach a state where it is no longer efficiently vaporizing the fuel, and thus is difficult to relight.  It then must be allowed to cool completely before priming it again.  Re-priming a warm stove risks a large fireball, caused by the raw fuel vaporizing on the warm burner before it can be lit with a match.  I did not actually have this happen with the Nova (though in my, ahem, youth I did manage to singe my eyebrows and beard off by trying to encourage a recalcitrant potbellied stove to light one morning, using some gasoline) so it's more of a theoretical danger of white gas as a material, and not a problem with the Nova.  If anything, the Nova is safer than most, due to the relatively small amount of fuel used for priming.

 

At an ambient air temperature of 70 F (21 C), the maximum period for which the stove can be turned off and then re-lit without re-priming is roughly 5 minutes. (At least that is how it behaved in my kitchen, when I decided to test how far I could push it.) Beyond that point, the stove does not re-light easily, and must be left to cool before priming it again.  At freezing, that period is considerably shorter, but by the same token the frigid air cools the stove down more quickly, so that I'm not unduly left twiddling my mittened thumbs.

 

For most backcountry cooking, this is not a big deal, but it takes a bit of getting used to, compared to butane or propane canister stoves, which are no-thought-required, light-and-go affairs.  In any case the easiest thing to do is turn the stove down to an extremely low simmer between potfuls, rather than turning it off entirely.  Still, in order not to waste fuel, a certain brisk efficiency in the cooking routine is called for.

 

2:  Purging the fuel line takes time and fuel. 
The stove continues to run for about a minute after the fuel bottle is flipped to purge the fuel line.  The extremely fuel-conscious hiker will want to take that into account and flip the bottle early, somewhere around 45 seconds to a minute before the food is actually done; thus the fuel being purged (all tenth-of-an-ounce of it) is used for cooking, rather than going to waste. 

 

That's a minute at full blast, by the way.  Flipping the bottle while the stove is at simmer will take two or more times as long to purge the line.  It is also typically harder to judge, when doing a meal where more careful cooking is required, when is a good time to flip the bottle.  One way to deal with this is to use the purge fuel to heat one last pot of water for dishwashing.

 

3:  Sticky fuel valve. 
I have noticed that the fuel valve tends to stick badly if allowed to cool while screwed shut, or if stowed for long periods screwed shut.  The solution, depending on the situation, is:  a) to shut the valve somewhat gingerly, if turning off just for a few minutes; b) to extinguish the stove in the standard fashion (purging the fuel bottle pressure) and let it cool with the valve open; and c) to stow it with the valve halfway open.  This, however, is the reason the lighting procedure includes the step of making sure the fuel valve is closed before pumping for priming.

 

 

Liquid fuel stoves are, as a category, not the most convenient to work with.  However, within the category, the Nova is a breeze.  (Which, admittedly, it had better be, considering its price, which is near the top of the range for one-burner backpacking stoves.)  It is easy and clean to prime, has a highly adjustable flame, is relatively light (for liquid fuel stoves, anyway) but nonetheless quite sturdy, packs small and clean, is very stable when deployed, and, given the right pan, cooks every bit as well as my kitchen range at home.  I'd say it is worth every penny.