a heat pump the actual saving is really dependent on how much water
is being used. Letís assume again a house with an existing 200L
100L of water is used per day, then the heat pump only needs to heat
100L per day. On the other hand, if the occupants of that house use
150L in the morning, 150L in the afternoon and 150L in the evening
then the heat pump would have heated 450L per day. Electricity
consumption figures have shown that a family of 4 with a 200L geyser
that uses water relatively conservative (only showers and also not
the high flow rate type) uses about 16kWh per day for the geyser.
this same family now have a heat pump installed they will use only
16 kWh/3.5 = 4.57kWh/day. Again assuming R1/kWh they would
R11.40 per day.
we now look at another family that have a big bathtub and some nice
high flow rate shower heads and we assume they are using 30kWh/day
on their 200L geyser (in other words the 200L geyser is reheating
more than once per day) then the same heat pump will now save them
R21.50 per day.
Conclusion Heat Pump Heating Savings
the theory and calculations above it can be seen that a domestic hot
water heat pump will provide a very similar saving for a family that
uses hot water conservatively and have a properly sized solar
however the demand on the geyser goes up a little, then the heat
pump will provide a better saving.
average electricity saving on the portion consumed by HOT WATER
heating with a standard electrical element with a SOLAR HEATING
SYSTEM would be
45% to 55%
The average electricity saving on the portion
consumed by HOT WATER heating with a standard electrical element
70% to 75%