I dont know if I can actually post the link of this report but I think even if its not up to date that every custumer should read before making their purchase .
Let me know what you guys think about this .
http://www.energyideas.org/documents/factsheets/EEF_Spas_HotTubs_Sept08.pdfThere were approximately 3.4 million portable spas1
in the U.S. in 2000 according to the National Spa
and Pool Institute. These spas consume an average of
2,514 kWh per year, making the average cost of heating
the spa more than $250 a year (at 10 cents/kWh).
According to a spa study by the Davis Energy Group,2
if you own a spa, it is the biggest electrical consumer
in the house.
How Spas and
Hot Tubs Use Energy
To understand how to reduce operating costs, it’s
a good idea to know how spas and hot tubs use
energy. They typically use electric energy to heat
and continuously circulate the water, and a very
small amount of electricity for lighting. Over 95%
of the time tubs are covered and unused, yet this is
when 75% of their energy
use occurs. Thus, energy
conservation starts with a
good look at this “steady
state” mode and at reducing
heat losses from the cover
and walls. While most of
the energy used in spas goes
into the heater, the energy
used for pumping is also
significant.
When the cover is removed
and the tub is being used,
heat losses increase six-fold
or more. If the jets are
activated and a couple of people get into the tub,
evaporative heat losses from the surface increase even
further, and pumps for the high-speed jets use many
times the energy of circulating pumps. If an air pump
or bubbler is activated, heat losses increase beyond
the capacity of most heaters and water temperatures
begin to drop.
The circulator pump(s) move water through a filter
and heater continuously during steady-state operation.
Some tubs employ a two-speed motor, with the
same pump used for low-speed circulation in steadystate
mode and for high-speed operation when using
the jets. These pumps are not usually very efficient
in any mode – but particularly in steady-state mode because the motor is very lightly loaded and running
at low efficiency most of the time. Since these are
air-cooled motors, getting rid of the waste heat from
the motor in the summer is a problem too.
Some manufacturers use separate pumps for circulation
and jets. While initial costs are slightly higher,
this helps optimize the circulation pump and can
yield good savings during steady-state operation.
A few studies have looked at the potential for
reducing spa energy use.5, 2 In the Davis study the
long-term savings of several efficiency measures were
estimated:
• Improvements in spa covers were estimated
to save 10%, or about 250 kWh
annually - the same amount of energy as
improvements to tub insulation.
• More efficient pumping systems will save
even more – 15%, or about 375 kWh/yr.
• Improved controls can save an estimated
5%, or 125 kWh/year.
If you are paying .085/kWh for electricity, you can
save $21/year with spa covers, another $21/year with
tub insulation, $32/year with improved pumping
systems, and about $11/year with improved controls.
Other than replacing the cover, these improvements
in efficiency will only be available at the time of
