While seeking options to reduce my electricity bill, I was recommended to consider a heat pump which purportedly would consume much less energy than my geyser. In this post, I will share how I used Chat GPT to quickly learn about heat pumps and evaluate the potential savings on energy.
What’s A Heat Pump
So I asked Chat GPT to explain to me in layman’s term what is a heat pump and how does it work, and got a the following answer.
A heat pump is a device that moves heat from one place to another, using a small amount of energy. It works a bit like a refrigerator, but in reverse. Here’s a basic breakdown of the process:
- Absorbing Heat: The heat pump contains a liquid called a refrigerant, which absorbs heat from the surrounding air or ground. When it absorbs heat, the refrigerant turns into a gas.
- Compressing the Refrigerant: This gas is then compressed by a compressor within the heat pump. When the gas is compressed, it heats up even more.
- Transferring Heat: This hot gas then travels through a series of coils where it releases its heat into your home (if the goal is to warm the house) or outside (if the goal is to cool the house). As it releases the heat, the refrigerant cools down and turns back into a liquid.
- Repeating the Cycle: The refrigerant then returns to the starting point to absorb more heat, and the cycle continues.
This process can be reversed to cool a home by extracting heat from inside the house and releasing it outside.
In summary, a heat pump moves heat rather than generating it directly, making it an energy-efficient way to heat and cool a home.
In the addition to the answer by Chat GPT, I got the following picture from using a Google search from the powerpal website to further illustrate how a heat pump works.
Power Consumption
I then asked Chat GPT to compare the power consumption of a geyser to heat pump when heating 100 litres of water from 20 to 60 degrees Celsius.
Chat GPT first described two key parameters of the datasheet of heat pump that I uploaded as follows.
- COP (EN 16147 / A20): The “A20” in this context refers to the ambient temperature condition at which the Coefficient of Performance (COP) is measured. The COP of 3.55 is measured when the ambient air temperature is 20°C. This is a standard condition used in EN 16147 to ensure consistent testing and comparison of different heat pumps.
- Auxiliary Power Consumption of 1.5 kW: This refers to the power consumption of an additional heating element in the heat pump. This auxiliary heater is typically used to boost the temperature or provide heating when the heat pump alone cannot meet the demand, especially during peak load times or when external temperatures are too low for the heat pump to operate efficiently.
Chat GPT then proceeded with a model of a normal geyser and calculations of the power consumption.
Assumption for Normal Geyser: A typical electric geyser (water heater) has an efficiency close to 100%, meaning almost all the electrical energy is converted into heat. For simplicity, let’s assume it has an efficiency of 1 (or 100%).
Heating Water to 60°C: Let’s calculate the energy required to heat a certain amount of water to 60°C for both systems.
Formula: The energy required to heat water is given by ( Q = mc\Delta T ), where ( Q ) is the heat energy, ( m ) is the mass of water, ( c ) is the specific heat capacity of water (about 4.186 J/g°C), and ( \Delta T ) is the temperature change.
Let’s do a sample calculation for heating 100 liters of water from 15°C to 60°C for both the heat pump and a normal geyser.
For heating 100 liters of water from 15°C to 60°C:
- Normal Geyser: It would require approximately 5.23 kWh of energy. This is based on the assumption that the geyser is 100% efficient in converting electrical energy to heat.
- Heat Pump (SHP-A 220): It would require approximately 1.47 kWh of energy. This lower energy requirement is due to the heat pump’s high efficiency, as indicated by its COP of 3.55.
As per these calculations done by Chat GPT, the heat pump seems to be significantly more energy-efficient compared to a normal electric geyser for heating the same amount water over the same temperature difference.