Thermal pots and slow cookers both keep soup or stew warm for long periods of time but have different technologies. Thermal pots do not use electricity and instead rely on vacuum insulation and reflective linings to reduce heat transfer, allowing food to stay warm for up to 8 hours. In contrast, slow cookers use electricity and a thermostat to maintain a constant temperature. While both appliances have similar functions, thermal pots provide benefits such as portability, versatility for hot or cold use, and gentler cooking that retains food color and texture compared to slow cookers.

1. Thermal Pots Versus Slow Cookers

2. You've seen these two products on the market. You've known
their function, what they are used for in the kitchen. You've
seen many different brands out there as well. You are
confused if these two kitchen-must-haves have any
difference at all.

3. This article is to tell you, they have no difference at all in
terms of functionality but they do have a difference in terms
of technology. Both of the kitchen wares do keep your soup
or stew warm for long periods of time but one uses
electricity while the other one does not. We shall make
some simple comparison (without sounding like a science
lesson here) between the two of them. Let's start with the
slow cooker first.

4. The slow cooker uses electricity with a thermostat attached at
the bottom of the pot to keep the soup/stew warm
throughout the day or any long periods of time. Since it's a
thermostat, of course you can adjust the desired
temperature to be kept at. The inner pot is using the
"conventional Chinese method" of retaining warmness that
is, using some stone material such as ceramic or porcelain.
Electricity is supplied to the thermostat and it produces
heat constantly to the temperature that is set and this heat
is constantly "transferred" into stone inner pot from the
bottom. Heat convection takes place within the inner pot.
Since the inner pot is made of thick stone material, heat
loss still takes place but at a slower rate

5. If you notice the inner walls of the outer pot of the slow
cooker, you can see it is glossy silverfish surface. This
further slows down the rate of heat loss using the laws of
radiation. As for the top of the inner pot, the lid is usually
made of thick glass material to prevent heat loss as well.
This is how the slow cookers works and remember the fact
that it uses electricity to achieve heat retention.

6. Now let's move on to thermal pots. To put it simply, it makes
use of the same heat transfer theory as what you have
known or learnt from vacuum flasks in physics during
school or anywhere. It uses the laws of heat convection,
conduction and radiation to help aid in heat retention.

7. Heat conduction and convection is reduced greatly (but not
totally as this is not possible) by means of vacuum.
Vacuum is a better insulation compared to foam. Now at
the sides or walls of the thermal pot, there is an outer wall
and inner wall. In between these walls is the vacuum. With
the presence of vacuum (okay okay, I promise no science
lessons here but just good to know that vacuum contains
close to zero number of atoms), heat conduction and
convection is greatly slowed down.

8. Infrared radiation is reduced by means of the silvering linings
(like a mirror) on the sides or walls of the outer pot. In
addition, the double lids (the inner pot lid and the outer pot
lid) and the insulation support at the bottom of the thermal
pot helps reduce the process of heat loss. With the
combination of vacuum and silver linings, it greatly reduces
heat transfer by convection, conduction ands radiation.

9. If a vacuum flask can retain temperatures of both hot and
cold for long periods of time under the same heat transfer
theory, a thermal pot can do so too.
Now that we know how thermal pots work, we proceed to
compare how different they are to slow cookers.
Electricity: the slow cooker uses it while the thermal pot does
not and therefore it saves money.
Safety: the slow cooker needs to be turned on for as long as
you want you soup/stew to be warm. The thermal (inner)
pot needs only 10-15 minutes on the gas stove before
placing into the outer pot for it to self-cook. Both scenarios
are assuming that you are out at work and not at home to
look after the soup/stew.

10. Versatile: the slow cooker needs a power point all the time for
it to operate and hence not convenient to bring out for
picnics or any outdoor activities. The thermal pot, since it
can self-cook the moment it leaves the gas stove, can be
brought to almost anywhere for up to 8 hours.
Multi-function: the slow cooker can only deal with warm-hot
purposes. The thermal pot can deal with both hot and cold
(such as using it as an ice-box or keeping cold drinks)
purposes.

11. Cooking ability: the slow cooker have a higher chance of
"overcooking" when compared to the thermal pot. Since the
thermal pot is a much slow cooking (and "natural") method,
foods such as vegetables and meat will be retain in terms
of colour and tenderness. Soups in thermal pots have been
reported to remain clear after being left "alone" after a day
of work. This is based on actual experiences from real
users of the thermal pot who have switched over from slow
cookers.

12. More info here:
http://www.silvericlick.com/
http://ezinearticles.com/?Thermal-Pots-Versus-Slow-
Cookers&id=4053143