Handwarmers S07E01: Why the Zippo Underperforms
Channel: Mountain Parameters
Date: 2022-10-28

The most asked question I get is, "why does my zippo still not perform well even though I replaced the catalyst?"

Indeed, although being a very popular product, the Zippo does not perform as well as handwarmers that cost a fraction of the price.

To understand why, look no further than the same principles that govern your fireplace chimney stack.

A handwarmer depends on the evaporation of fumes to move up into the catalyst head to support an exothermic reaction. To evaporate efficiently, there needs to be heat to support the transition of liquid to fuel.

When a handwarmer reservoir has sufficient heat to start the evaporation of the liquid fuel, it needs that heat to be maintained to keep the fumes gassing into the catalyst head.

So, why does this cheap Butterfly handwarmer seem to do that job better than the Zippo?

In physics there is a principle called the "Thermal Flywheel Effect". For example, when external temperatures in your jacket pocket are fluctuating throughout the day, a large thermal mass within the insulated portion of your pocket can serve to "flatten out" the temperature fluctuations that affect the handwarmer.

This zippo reservoir weighs 54 grams.

This Butterfly reservoir weighs 70 grams.

The zippo has about 33% less mass then the Butterfly. Also, because the reservoir on the Zippo is thinner, the volume of fuel it can store is less.

All this adds up to underscoring the importance of prewarming your Zippo before activating it, and keeping it warm in the field to prevent cold shocking it.

Timeline:
00:26 Compare to Butterfly handwarmer
00:35 Red Star handwarmer
00:40 Mini handwarmer
01:00 Catalyst heads explained
01:12 Exothermic reaction principles explained
01:30 Importance of heat to liquid fuel evaporation
02:00 "Thermal Flywheel Effect" explained as to relevance to operating your handwarmer
02:30 Comparing the relative thermal mass of a cheap chinese handwarmer to a Zippo, and why it is important
03:00 Comparing the thickness of the reservoirs Butterfly/Zippo relative to influencing thermal mass
03:15 The importance of pre warming the handwarmer before activating
03:40 Introducing the grandaddy of handwarmers, the Jon-e Giant, and comparing it to a Zippo.