What is a heat pump water heater and how does it function?
Heat pump water heaters transfer heat from one place to another using electricity. They’re alternatives to solar panels and don’t generate heat directly. They’re perfect for heating domestic hot water via an integrated heat pump. The result? They’re up to two or three times more energy efficient and reduce energy costs that conventional electric resistance water heaters would chew up.
Think of a hybrid heat pump water heater like a refrigerator working in reverse to move the heat along. Using a compressor, the heat pump water heater pulls heat from surrounding air. It transfers this into a storage tank to heat the water.
A heat pump water heater isn’t only more energy efficient, but tankless water heaters supply your water on demand and offer more compared to a new storage tank water heater.
Heat pump water heater – pros and cons
With numerous designs and options on the market, what makes a heat pump water heater your best solution? Let’s look at some pros and cons:
- Cools air: In summer your heat pump water heater cools its surrounding space creating a more comfortable indoor climate.
- Durable: If you take good care of your heat pump water, it can last up to 15 years.
- Efficient: Heat pump water heaters are designed to save energy. They don’t have to work hard to generate heat because they use heat from the surrounding air. They can be up to two and a half or three times more energy efficient than conventional electric water heaters.
- Environmentally friendly: Heat pumps don’t emit any toxic emissions or gas leaks.
- Safe: Due to no heat generation, the unit’s exterior isn’t hot. It’ child and pet friendly.
- Uses waste heat: In winter your heat pump uses waste heat from the central furnace to operate.
- Pricey: A heat pump water heater costs roughly double the price of an electric resistance water heater. You’ll need to probably retrofit your plumbing and electric system. While purchasing one is initially expensive, you’re investing in long term benefits. You’ll save plenty on energy costs for up to 10 or more years. This could add up to over $300 annually for a family of four.
- Noise: You do hear the compressor. This can be reduced by insulating the mechanical room, but it consequently decreases the warm air the pump would use.
- Space: A heat pump water heater needs additional space of up to 1,000ft³ as well as a condensation drain or pump.
- Time: In peak times you might wait for your heat pump water heater to produce large volumes of hot water and recover thereafter. If you have a large family this could become frustrating, particularly in winter when everyone wants to shower at the same time.
- Works harder in winter: The pump generates cold air while operating, so the heating system therefore functions even more in colder months.
Features to consider when choosing a heat pump water heater
When browsing the numerous heat pump water heater offerings make sure you’ve considered various features before finalizing your selection. Remember you’re investing in something you’ll use every day, so it must work and last. Let’s explore type, capacity, energy factor, noise level, display, warranty, weight and dimensions & further expand on the features covered in our best heat pump water heater reviews.
The three main types of heat pump water heaters are storage tank, tankless and hybrid electric. Each has its benefits and drawbacks. Here’s the lowdown before you take your pick:
The most common of water heaters, a storage tank water heater heats and stores water in an insulated tank until it’s needed. A pipe on top releases this water when necessary. A temperature and pressure relief valve opens if either of these exceeds a preset level.
A natural gas water heater consumes less energy and costs approximately 50% less to run compared to an electric water heater, but gas models are pricier initially to purchase.
Tankless water heaters use heating coils to heat your water as and when you need it. They’re more energy efficient, but the limited flow of hot water per minute varies according to your inlet water temperatures. This best suits homes using natural gas for heating water. Electric models could be an expensive upgrade for your home’s electrical capacity.
You may need to upgrade your gas lines, electric service and invest in new venting for this system. It’s less complicated to replace an old water heater with a hybrid heat pump.
Tankless water heater don’t hold a large amount of water, but the Gallons Per Minute (GPM) rating indicates how much hot water is delivered over a fixed time period. Tankless options include the Rheem RTGH-95DVLN, Stiebel Eltron 224199 and EcoSmart ECO 11.
Hybrid water heaters move heat instead of creating it. A hybrid heat pump water heater absorbs heat from the surrounding air and transfers it to the water, storing it in a large tank. Moving heat requires less energy, so hybrid heat pumps are doubly efficient compared to standard and tankless electric water heaters.
Hybrid heat pump water heaters can also cool your basement, home or garage. You’ll save on air conditioning costs in the summer months if your water heater is inside your home.
Hybrid water heaters are also eligible for tax credits of up to $300, and they don’t require the amount of retrofitting that tankless water heaters would.
A hybrid water heater is more expensive than a traditional water heater. It also requires more space, a condensate drain and the air filter needs to be replaced.
The best hybrid water heater options we’ve reviewed include the A.O. Smith HPTU-50 or Westinghouse Water Heater units.
Heat pump water heater capacity is linked to your available space and personal requirements. Consider what you’ll be using this heat pump water heater for. Determine how many applications your unit can run simultaneously at your chosen location inlet water temperature.
Tank water typically holds between 40 and 55 gallons but can also hold more. The ideal size depends on how many people reside in your home and your peak water usage patterns.
Smaller capacity options include the EcoSmart ECO 11, Stiebel Eltron 224199 and Rheem RTGH-95DVLN. The EcoSmart ECO 11 offers the highest GPM rating of 9.5, so it’s is perfect for a large family using multiple bathrooms.
For larger volumes of water, consider the A.O. Smith HPTU-50 and Westinghouse Water Heater products.
Saving energy is key! Opt for a heat pump water heater that uses minimal energy. All the products we’ve reviewed boast impressive energy factors.
The Stiebel Eltron 224199 only works when you require hot water, so you won’t lose anything while it’s in standby mode. The Westinghouse Water Heater also promotes minimal standby loss per hour.
Mechanical components in heat pump water heaters tend to be rather loud. They’re noisier than most refrigerators which have a noise range from 40-50dB. While noise level varies from model to model, the Stiebel Eltron 224199 and A.O. Smith HPTU-50 are particularly rated for their silent operation.
Digital display makes operation easy. Monitor your levels and customize usage. The handy vacation mode on the A.O. Smith HPTU-50 allows you to set that only the heat pump is used for increased efficiency while you’re not at home.
The Rheem RTGH-95DVLN, Stiebel Eltron 224199 and EcoSmart ECO 11 all offer digital display. The added benefit of the EcoSmart ECO 11? The digital temperature control to set your temperature in one degree increments. The Stiebel Eltron 224199, EcoSmart ECO 11 and A.O. Smith HPTU-50 all feature LCD displays.
You don’t want a broken heat pump. Even worse, one that can’t be replaced. While you don’t want to send a product back for repairs or replacement parts, a warranty is useful. Always check what each heat pump offers regarding its warrantee. This could range from a limited plan including a few leakages or parts up to 12 years to a lifetime limited warranty.
Longer warranty models are pricier. The advantage? A larger element or burner that increases water heating speed, plus the thicker insulation against heat loss. It’s best to pick a water heater offering the longest warranty available.
Of the best heat pump water heaters we’ve reviewed, the EcoSmart ECO 11 and Westinghouse Water Heater pumps have the longest limited lifetime warranty.
The EcoSmart ECO 11 offers a lifetime warranty on electronics, exchanger and element. But the warranty doesn’t cover labor or any accidental damages, and only the cost of the heater, so consider these details when you compare different models’ warranty guidelines.
The Westinghouse Water Heaters offers a limited lifetime warranty for residential units when registered online. This covers the tank but not parts, and only covered if it’s installed by a licensed plumber. Always adhere to the product registration rules to benefit from warrantees.
The weight of a heat pump water heater is also important when you consider your available space and where it will be mounted. Like capacity, weight also determines how much water a tankless water heater holds.
The lightest model we’ve reviewed is the EcoSmart ECO 11 at 6.5lbs, and the heaviest is the A.O. Smith HPTU-50 at 180lbs.
Determining these specifications and electrical infrastructure helps you know what will fit onto your breaker panel. You need to know the amp power, double pole quantity and amp breaker requirements. Before purchasing a heat pump water heater, ensure you can accommodate the power supply with sufficient space for this unit in your breaker panel.
Consider your available space to know whether you require a large or small heat pump water heater. A new water heater might not fit exactly in the place of your previous one. Due to possible increased insulated and other efficiency related improvements, a newer model may be wider or taller than ones you considered before.
Prior to purchase always check the product model is the correct size for your expected demand and electrical requirements.
The smallest heat pump we’ve rated is the EcoSmart ECO 11. It’s ideal for small living spaces. The largest unit we’ve reviewed is the Westinghouse Water Heater. It also holds the largest gallon capacity, making it the best 80 gallon heat pump water heater.