Hot Water Heat Pump System
Hot water heat pump
Usually, when you think of solar water heating, you think of panels and
heat collectors installed on the roof—traditional solar water heating systems.
However, you can also make a hot water heat pump.
A heat pump uses renewable energy to heat water in a different way-no
solar panels are needed! Heat pumps can save you a lot of hot water costs,
because they use about one-third of the energy of electric water heaters. In
addition, there are generous rebates, making them a very economical choice!
How does heat pump hot water work?
The heat pump is a bit like a reverse refrigerator. It transfers the
heat in the air outside the equipment to the water stored in the heater through
the heat exchange system. As far as heat pumps are concerned, "heat"
is a relative term because they will still work in very cold conditions*-at
least -10 degrees Celsius, so it will still provide you with hot water during
winter nights. How can this be?
1. The outside air is sucked into the heat pump system through the fan
and enters the evaporator. The evaporator contains a special type of
refrigerant, which is stored in the pipeline. The refrigerant used is called
R134a, which is not CFC, so it will not have a negative impact on the earth's
ozone layer.
2. The evaporation point or boiling point of R134a is -26C; and the
boiling point of water is 100 degrees Celsius. The temperature that feels very
cold to us is still enough to make the refrigerant "boiling". The air
drawn into the system is much hotter than the refrigerant, and the refrigerant
changes from liquid to gas in the heat pump pipes.
3. The compressor then pumps the current gaseous refrigerant through a
small valve, which compresses it; and therefore generates a lot of heat.
4. The heat exchanger transfers heat from the heated refrigerant gas
pipe to the water tank that stores the water.
5. As the heat is taken away, the temperature of the refrigerant now
drops sharply, so it returns to the liquid state, and the heat pump cycle
starts again.
Type of heat pump system
There are two types of hot water heat pumps:
1. Integrated system
2. Split the system
1. Integrated system
In the integrated system, the heat pump is usually installed on the top
of the storage tank, including:
1) Evaporator
2) Fan
3) Compressor
4) Condenser
5) In some cases, the evaporator (which absorbs heat from the air) is
separated from the air tank or wrapped around the air tank.
Because these systems are integrated in one unit, they are usually
heavier than split systems.
2. Split system
In a split system, the evaporator, fan, and compressor are located in a
single unit and are connected to the gas cylinder through a refrigerant
pipe-the heated refrigerant gas passes through a heat exchanger located in the
gas cylinder to heat the water. They are very similar to split system air
conditioners.
Operating cost of hot water heat pump
The heat pump hot water system consumes much less electricity than the
electric storage hot water system. This is because it only uses electricity to
drive the compressor and fan, instead of using electricity to directly heat
water with electric elements.
If the cylinder is large enough, these systems can operate overnight at
cheaper off-peak electricity prices. But it is important to ensure that the
system size is suitable for your needs.
These systems can also operate at peak electricity prices, which means
they heat water during the day while you use them.
If you have a rooftop photovoltaic (PV) system to generate electricity,
it may be beneficial to run a heat pump water heater during peak electricity
bills, and use a timer to limit the water heating time to the middle of the
day. This will make better use of the photovoltaic system to produce Because it
will reduce the amount of electricity output to the grid.
Hot water heat pump installation and maintenance
The correct installation and maintenance of your heat pump hot water
system can optimize its energy efficiency.
The correct installation depends on many factors. These factors include
fuel type, climate, local building code requirements and safety issues.
Therefore, it is best to have a qualified plumbing and heating contractor (or
geothermal heat pump system installer/designer) install your heat pump.
When selecting qualified professionals, please do the following:
1. Request a cost estimate in writing
2. Seek reference
3. Check the company with your local Better Business Bureau
4. See if the company will obtain local permits and understand local
building codes when necessary.
Regular maintenance of the water heater can significantly extend the
service life of the water heater and minimize efficiency losses. Read your user
manual for specific maintenance recommendations.
Improve energy efficiency
After the water heater is properly installed and maintained, try some additional energy-saving strategies to help reduce hot water costs. Some energy-saving equipment and systems are more cost-effective to install with water heaters.
