Residential hot water heat pumps
Hot water heat pumps are an energy-efficient and environmentally friendly alternative to conventional hot water systems. They use 60-75% less electricity, making them cost-effective in the long run. There are two main types of hot water heat pumps – integrated and split systems. Integrated systems combine the heat pump and hot water cylinder in one unit, typically installed outside. Split systems have separate outdoor units and hot water cylinders, offering more flexible installation options.
The operation of hot water heat pumps involves a vapour compression cycle. This cycle extracts heat from the air and transfers it to the water. The refrigerant absorbs heat, is compressed, and then transfers the heat to the water in a condenser coil. This process is highly efficient, using less electricity than electric resistance and gas systems, and results in lower CO2 emissions.
Hot water heat pumps come with some limitations, however. They have higher upfront costs compared to conventional systems and typically have a shorter lifespan of eight to 15 years. Additionally, they can be noisy because of the fan and compressor, and their efficiency drops in colder temperatures.
When compared to other systems, electric hot water cylinders are cheaper to install but have higher running costs and emissions. Gas continuous flow systems have similar installation costs to electric cylinders but also come with higher operational costs and emissions.
Hot water heat pumps are best suited for homes with high hot water usage, standalone homes, and those with underfloor heating or radiators. They use refrigerants with varying global warming potentials, with newer options being more environmentally friendly.
For more in-depth information see EECA’s article on Hot water heat pumps in the home.
Overview
- Energy efficient: Uses 60-75% less electricity
- Environmentally friendly: Lower CO2 emissions
- Cost-effective: Cheaper to run over time
- Higher upfront costs: More expensive to purchase and install
- Best for high hot water usage homes: Ideal for homes with high hot water demand
