Rinnai RIN250EHP Installation And Owner's Manual page 16

Safety
This appliance is not intended for use
by persons (including children) with
reduced physical, sensory or mental
capabilities, or lack of experience and
knowledge, unless they have been given
supervision or instruction concerning
use of the appliance by a person
responsible for their safety.
Children and animals should be
supervised to ensure that they do not
interfere with the appliance.
How Does The Heat Pump
Module Work?
A heat pump uses complex
thermodynamic principles to extract
energy from ambient air and transfer this
energy to water that is in contact with
the unit's immersed heat exchanger.
The heat pump's operational principles
are similar to those used in a normal
domestic refrigerator, except in reverse.
In a refrigerator, heat energy is drawn
from inside the refrigerator (making things
cold), concentrated by the compressor
then dissipated to the atmosphere via the
condenser coil located on the back of the
refrigerator cabinet.
In a heat pump system, outside air
is drawn into the unit and across an
evaporator coil by a fan. The evaporator
coil captures the energy in the air and
transfers that to cold liquid refrigerant,
contained inside the evaporator, causing
the refrigerant to increase in temperature
and evaporate into a warm gas.
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Owner's Manual
Installation and Owner's Manual – Heat Pump
The warm gas on exiting the evaporator
passes into a compressor where
compression causes the temperature of
the gas to increase further, becoming a
superheated (hot) gas.
The superheated gas is pumped from
the compressor to a water immersed
condenser coil, where it gives up its
heat energy to the water. When the
superheated gas gives up energy, it
condenses back to a liquid, and on
exiting the condenser coil, it passes
through an expansion control valve (TX
valve).
The TX valve acts as an automatically
adjusting tap that controls the amount of
liquid refrigerant that is allowed to pass,
once more, into the evaporator. This
is necessary to constantly match the
amount of liquid entering the evaporator
to the available energy in the air passing
through the evaporator so that the entire
liquid refrigerant that enters evaporates
and exits as a gas only.
How Do I Operate The System?
The operation of your water heater is
fully automatic, so you only need to
connect the water and electricity supply
and then turn on the electricity.
The heat pump module is electrically
connected to the storage tank and
will start automatically when the water
temperature in the storage tank falls
below 55°C and continue to run until the
water temperature of the complete tank
H4123 025961 Rev. A July 2012