Picking the Right Heat Pump Water Heater
We install two main types of energy-efficient heat pump water heaters. Which one is right for you? It depends on your space, goals, panel capacity, and whether you want to use solar panels.
Hybrid Heat Pump Water Heaters
In hybrid systems, the heat pump compressor is located on top of the hot water storage tank, making them a single integrated unit. They extract heat from the surrounding air, pull it over the refrigerant coils on top of the unit, and then move the heat downward, to be stored in the hot water storage tank below. This part can be ducted out too.
These water heaters are called hybrid heat pump water heaters because they have two methods of heating the water: heat pump mode and electric resistance heat mode. The heat pump mode is the efficient mode and should be used as much as possible. If an additional boost is needed, the electric resistance heat can be used to supplement heating.
Many companies, including Rheem, AO Smith, and Bradford & White, manufacture hybrid heat pump water heaters.
Split System Heat Pump Water Heaters
The second type of heat pump water heater is a split system. The main model in this category is the SanCO2, made by Eco2 Systems.
Split units have a larger initial upfront cost compared to hybrid heat pump water heaters but they’re ideal in most other ways. They are a “split system,” meaning that the hot water storage tank is separate from the heat pump and stays outside. The heat pump heats the water from the tank and sends it back hotter.
The storage tank inside your home makes no noise as it has no moving parts. These heaters use CO2 as a refrigerant, which is environmentally friendly since CO2 has a Global Warming Potential (GWP) of 1. Lastly, these types of water heaters are very well-built and reliable.
Considerations When Selecting a Water Heater
Available Space
Heat pump water heaters generally have a storage tank for hot water. It’s ideal to have a storage tank with a high volume, like 80 gallons. This allows you to set up the heat pump water heater not to turn on during peak hours when energy is expensive. Therefore, it is good to have a larger tank to act as a thermal battery so you can pre-heat the tank before peak hours and have that extra volume of hot water ready for use when peak hours begin.
Electrical Panel Capacity & Heat Pump Water Heater Type
Hybrid heat pump water heaters come in either 120v or 240v, with varying amperage options. SanCO2 heat pump water heaters are 240v and 15 amp.
The only difference between a 30 amp hybrid heat pump water heater and a 15 amp hybrid heat pump water heater is that the less efficient electric resistance heating elements are larger with a 30 amp. Since the dramatically more efficient heat pump mode of these hybrid units should be relied upon as much as possible, the 30 amp versions tend to be less ideal.
Water Heating - Frequently Asked Questions (FAQs)
What’s the difference between a hybrid and a split-system heat pump water heater?
A hybrid heat pump water heater ,available from manufacturers like Rheem, AO Smith, and Bradford & White ,combines heat pump mode with a backup electric resistance mode in a single tank-based unit. A split system, like the SanCO2 from Eco2 Systems, keeps the hot water storage tank separate from the heat pump, with the heat pump unit living outside. Which one fits depends on space and electrical considerations, not just preference.
Why does a heat pump water heater need 120V or 240V, and does that affect my choice?
Hybrid units can run on either 120V or 240V depending on the model, while a split system like the SanCO2 can operate on a 15-amp circuit. The voltage and amperage requirements factor directly into whether your home’s existing electrical setup can support the unit as-is or needs adjustment.
What is the CO2 refrigerant used in a split-system water heater, and why does it matter?
Split systems like the SanCO2 use CO2 as the refrigerant, which has a Global Warming Potential (GWP) of just 1 ,dramatically lower than many conventional refrigerants. That makes the environmental footprint of the unit itself, not just its energy source, part of what makes a split system an efficient choice.
How much space does a heat pump water heater actually need?
Available space is one of the first things evaluated, since hybrid units need enough clearance around the tank for the heat pump to draw in air effectively, while a split system’s separate outdoor unit changes the space equation entirely. It’s a key factor in recommending one type over the other.
Will my home’s electrical panel handle a heat pump water heater, or do I need an upgrade?
It depends on the unit and the panel’s existing capacity ,this is evaluated alongside available space as one of the two main considerations when selecting a water heater, since the electrical requirements differ meaningfully between hybrid and split-system options.
Is an 80-gallon tank the right size for most homes?
80 gallons is generally recommended as the ideal storage volume for a hybrid heat pump water heater, since it provides enough buffer for the heat pump to recover at its normal, efficient pace rather than triggering the backup electric resistance mode too often.
Schedule a Free Assessment
Your comprehensive assessment begins with an in-depth call with one of our home efficiency experts, where you can ask all your questions. During our conversation, we’ll ask about your goals, the current setup of your home comfort system, and any time and budget constraints you might have. If you want to move forward with a home evaluation, we can schedule it during your assessment.
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