Air to Water Heat Pumps Explained
What is an air to water heat pump
First of all, what is a heat pump? As you know, the inside of your refrigerator is cool, but the back is warm. This warmth is the heat that the refrigerator takes from the items you put in the refrigerator to cool. Simply put, the heat pump is just a refrigerator, it tries to cool the external environment, so it transfers heat to your home. An air-to-water heat pump or air source heat pump (ASHP) extracts this energy from the air in the external environment.
Where can I use an air-to-water heat pump?
Air-to-water heat pumps generally perform poorly at freezing temperatures. In climates with temperatures below freezing in winter, air-to-water heat pumps may not meet all of your heating needs. If you want to install a gas heating system as a backup, you can overcome this problem. However, air-to-water heat pumps designed for cold climates can also solve this problem.
How does an air-to-water heat pump work?
A complete and modern heat pump system can effectively save energy and reduce carbon dioxide emissions. Due to the integrated water heater, immersion heater, circulating pump and climate system of the indoor unit, heating is safe and economical. The heat is obtained from the outdoor unit through the outdoor unit, and the refrigerant circulates in the closed piping system to transfer the heat from the heat source to the indoor unit. The standard of heat transfer can be simplified as follows:
1. An outdoor unit takes heat from the surrounding air and transfers it to a coolant
2. A compressor increases the temperature of the refrigerant
3. The coolant transfers heat to the hot water storage tank via a heat exchanger
4. Circulate hot water to the radiator and faucet
5. The cold water is transported back to the tank
6. Transfer the coolant from the tank to the outdoor unit
Reverse the above process, the refrigerant in the outdoor unit will absorb heat from the water and release it to the external environment, so the heat pump can cool the home when necessary.
The benefits of air to water heat pump:
Compared with traditional fossil fuel systems (such as oil or gas boilers), the cost of heating your home with air-to-water heat pumps is usually 50% to 60% lower. Simply put, the "efficiency" of air-water heat pumps ranges from 320% to 400% or higher, and even condensing boilers are only 92% efficient. This basically means that for every 4 units of heat input into your house or building, 3 of them are not affected by the external environment. The main benefit of air-to-water heat pumps for homeowners is that they are very efficient, thereby reducing heating costs for your house or building. Since most of the heat energy provided to your house comes from nature, it has a very low carbon footprint compared to "traditional" fossil fuel-based heating systems and provides a better energy rating.
Air to water heat pump type:
There are basically two main types of air-to-water heat pumps, split systems and Monobloc systems.
The split air to water heat pump is composed of an outdoor heat exchanger and a fan unit, a compressor and an indoor unit. The two units are connected by refrigerant pipes. The outdoor unit extracts heat from the air and transfers this heat energy to the refrigerant in the system. The refrigerant is compressed to a high temperature and circulates to the indoor unit. The indoor unit has a heat exchanger that absorbs high-temperature heat from the refrigerant and transfers it to the water circulating to the heating and hot water system.
The Monobloc air-to-water heat pump consists of an external unit, which contains an air-to-refrigerant heat exchanger, a compressor, and a refrigerant-to-water heat exchanger. In this integrated unit, heat is extracted from the air and transferred to the refrigerant, the refrigerant is compressed to a higher temperature, and the heat of the refrigerant is transferred to the water circulating to the heating and hot water system. This external single unit is connected to your house or building through two water pipes similar to an external boiler system.