MSR 1.0L Reactor Stove

MSR 1.0L Reactor Stove w/ French Press

MSRP: $190

Cook Pot Size: 1.0L

Specs:

• Size (cooking pot only): 4.75 x 6.1 in. (12 x 15.5 cm)
• Stated Weight (stove & cook pot, without gas canister): 14.7oz
• Total burn time (w/ 8oz canister of MSR IsoPro fuel): Appx. 80 mins
• Stated boil time (1L of water using MSR IsoPro fuel): 3.5 mins
• Boil time as tested: See “Boil Time” section below

Test Location: Frank Church-River of No Return Wilderness, Idaho

Days Tested: 7

In 2001, Jetboil, a company from a small town in New Hampshire, invented the Flash, a lightweight fuel-efficient backpack stove sold as a self contained system (meaning the stove unit and fuel canister fit inside the Flash’s cooking pot for transport).

Jetboil has since gained a lot of popularity in the backpacking world and expanded their line of stoves to include other 1-2 person units like the Sol Advanced and Jetboil Sol Ti Premium cooking systems. (The Sol Ti, which we’ve reviewed, is a lighter version of the Sol Advanced that features a titanium cooking pot, but is otherwise identical to it).

However, Jetboil has faced some competition.

 

Enter the MSR Reactor. MSR (Mountain Safety Research) started developing camp stoves in the 70’s, and has a reputation for producing their own high-quality backcountry stoves.

The Reactor system is available in three sizes (1.0, 1.7, Liters and 2.5 Liters), is also self-contained, and is claimed to be “the fastest and most fuel efficient stove ever made.”

I’ve used a Jetboil Sol Advanced for backcountry Ranger work for the last six years. Given MSR’s claims about the Reactor’s performance, the unique design of its heating element, and the fact that it is a direct competitor to Jetboil’s Sol series stoves, I was very curious to see how the two compared. After testing the Reactor 1.0L on a couple of long trail clearing projects this fall, here are my findings…

Fuel Canisters: Fuel Mixture & Compatibility between Brands

Before covering the Reactor’s performance in the field, I’ll give a quick overview of how upright canister stoves (like the Reactor and Sol) work with some commentary on stove-canister compatibility. This may be of particular interest to those shopping for their first backcountry stove and are considering both the MSR Reactor and Jetboil Sol Advanced.

The fuel inside stove canisters is a mixture of three gases: propane, n-butane, and iso-butane, with propane as the main ingredient. Propane has a low boiling point (approx. – 43° F), but it also has high vapor pressure, so heavy steel containers are needed to contain it (think green Coleman bottles or the heavy tank under your gas grill). Butane is much easier to contain and has a higher boiling point of 31° F, but it doesn’t vaporize well at low temperatures, so it’s difficult to light a butane flame when it’s cold outside.

The fuel in stove canisters is a mixture of these two gases so it strikes a happy medium; propane drives the system with its high vapor pressure, butane burns at a lower temperature, and engineers can get away with thinner and lighter canisters to contain the gasses.

All stove canisters feature the Lindal self-sealing valve, a standard across the industry, making all brands’ stoves compatible with any gas canister. This presents some legal issues, as manufacturers effectively have no control over what brand gas is used with their stove. Brands face a liability if a stove blows up in someone’s face when that person happened to be using another brand’s canister. To combat this, manufacturers often put a label on their stove that says something to the effect of “must use [our brand] gas.” (And they want to sell their own gas…)

Issues that arise when using a Jetboil canister with an MSR stove, like getting insufficient fuel pressure when you turn the stove on, are not likely due to a problem with canister-stove compatibility. The real culprit is probably a faulty seal, the canister being over-tightened, or high-altitude operating conditions (above 10,000 feet). Any canister stove should work with any brand’s gas canister. Case in point: I used Jetboil branded gas with the MSR Reactor for this test.

Once your stove is screwed into place on top of the canister, assuming the Lindal valve is functioning properly, the pressurized gas mixture is only contained by the valve on your stove. Once that valve is opened, gas is pushed out of the canister and through the stove’s burner/heating element where it is vaporized and ready for combustion. A spark (from a lighter, match, or a built-in piezoelectric igniter) then ignites the gas and voilà, you have a flame to heat your cook pot.

Note that because canister stoves (the Reactor and Sol included) run on highly pressurized gas that creates a very hot flame, their valves basically function as ON/OFF switches. You can’t progressively turn down the heat/flame on the Reactor/Sol’s heating element the way you can on your stove at home to simmer something.

The Reactor and Sol Advanced are made to boil water only. (A non-canister stove like the MSR Whisperlite does allow the intensity of its flame to be adjusted, but is far less efficient)

Now let’s talk about the two biggest factors that separate efficient backpack stoves from marginal ones: heat transfer and heat loss.

Reactor Heating Element

Heat transfer is defined as the exchange of thermal energy between physical systems (in this case the Reactor’s heating element and its cooking pot) and is the most important factor in determining how efficient a stove is. Consistent with MSR’s claims, the Reactor really stands out in this respect.

Environmental conditions (wind, temperature and moisture) all affect a stove’s efficiency, and MSR designed the Reactor to be used in the harshest climates imaginable.

The Reactor is the only stove I know of that does not produce an open flame and, as such, is about as wind proof as upright canister stoves get. The engineers at MSR developed a dome-shaped, radiant heating element that fits snugly up against the bottom of the cook pot, protecting it from breezes.

There is no need to use a folding wind-screen with the Reactor; in the five nights I cooked with the Reactor, I never experienced any fade from wind. In comparison, the heating element on Jetboil stoves sits slightly below the cook pot and can be affected by windy conditions because it’s more exposed.

MSR designed the cook pot to off-gas via slits around the bottom of the pot, which allow heated air to rush up the entire bottom 1/3 of the cook pot.

As Dave Alie explains in his review of the stove, the Jetboil Sol Ti has a more conventional, open-flame design, but it features a “flux ring” that attaches to the bottom of the cooking pot. This helps contain the hot air that the stove emits and absorb some heat, transferring it to the pot directly via conduction.

Boil Time

MSR claims that the Reactor will boil 1 liter of water in 3.5 minutes, though this number is based off of a lab-test in controlled conditions. Jetboil claims the Sol Advanced will boil 0.5 liter of water in about 2 minutes and 15 seconds. Accounting for the difference in the amount of water used in each claim, this still suggests the Sol should be slower than the Reactor when it comes to boiling times.

Before testing the Reactor in the field, I conducted my own controlled test to assess the boil times for both stoves. I boiled 16oz of tap water (of the same temperature) in both the Reactor and the Sol Advanced and timed the results. Both stoves’ canisters were full and the stoves were out of the wind, in my garage.

Sure enough, the Reactor is faster, hands down. The Reactor boiled 16oz (0.5 liter) of tap water to a full, rolling boil in just 87 seconds while the Jetboil Sol took 129 seconds to achieve the same rolling boil. The Reactor’s system is amazingly efficient.

However, there are a number of variables that can affect boil times in the field; everything from ambient air temp, elevation, the temperature of the gas canister, fuel levels, etc.

I used the Reactor at 7,400 ft. using very cold spring water, and in those real-world conditions, the boil times for 1 liter of water I recorded were close to the 4 minute mark (with a few slightly over 4 minutes). Still, judging from my past experiences using a Jetboil in similar conditions, the Reactor is quicker and more efficient on the whole.