11-09-2013, 03:46 PM
Heat Pumps and Electric Resistance Heating Systems
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Electric Resistance Heating
Electric furnaces, boilers and baseboards all work around
the same basic principle of electric resistance.
An electric current is run
through a metal wire or
coil, called the heating
element. When in contact
with electricity, the element
heats up.
This heat is then distributed throughout the home, either
through electric baseboards, furnaces or boilers.
Efficiency of Electric Resistance Heating
Regardless of whether you have an electric furnace,
boiler or baseboards, all electric resistance systems
work the same way:
1 kw of electricity = 1 kw of heat
A new electric resistance heating system will never
be more efficient than the old one. The only way to
improve electric heating is to incorporate another
fuel or technology.
How Heat Pumps Work
When a refrigerant is circulated past the heat source
(air or water) it will absorb heat energy. heat up even
more. The extra energy
causes the refrigerant
to evaporate into a
gas. The gas is then
compressed, causing
it to heat up even
more.
The compressed gas is then circulated past a heat
exchanger, where energy is transferred into the home
by a distribution
system (either air
or water). With
the heat removed,
the cooled gas
condenses, turning
back into a liquid.
Measuring Energy Efficiency
Since Heat Pumps operate differently than other heating
systems, they use different energy efficiency
measurements.
The efficiency of Air source heat pumps is measured using
the Heating Seasonal Performance Factor (HSPF),
Seasonal Energy Efficiency Ratio (SEER), Energy
Efficiency Ratio (EER).
The efficiency of Geothermal heat pumps is measured
using the Coefficient of Performance (COP) and Energy
Efficiency Ratio (EER).