Name: Akash P.
Status: Student
Age: 18
Location: N/A
Country: N/A
Date: November 2002
Question:
I walked into an appliance store yesterday and I saw
energy / efficiency ratings for gas stoves and microwaves. My question is
where does the wasted energy for a gas stove go? Assuming 40% efficiency,
where does the 60% go in a gas stove. I presume that some of it would
become infrared radiation, some pushes against the atmosphere. How can
the wasted energy be accounted for and what equations can one use for
that. ie. energy lost in IR, energy lost to surrounding air, energy lost
to stove.
Replies:
It is not clear how the manufacturer is defining "efficiency", or what the
configuration of the stove is. The latter has a big effect. In a gas stove
(I am not sure if you mean a furnace for heating a home or a cooking stove)
most of the heat loss occurs because hot CO2 and H2O go "up the stack" that
is there is not an efficient heat exchanger to capture all of the heat
energy. The infrared radiation produced is not really lost because it heats
the air surrounding the stove. I do not know of any simple equations to
describe in any detail what is going on.
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.
