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:
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.