Introducing the Accelera® E Heat Pump Water Heaters
Stiebel Eltron's Accelera® E series represents advanced heat pump water heater technology, engineered in Germany. These units are designed to provide comfort while delivering the lowest possible energy costs, reducing hot water expenses by up to 80%.
The Accelera® E has been the largest seller in Europe for over 35 years and is backed by a 10-year warranty, reflecting over 90 years of Stiebel Eltron's engineering and manufacturing reliability.
Key Benefits:
- Designed to provide comfort plus lowest possible energy costs.
- Reduces hot water costs by up to 80%.
- Engineered in Germany, Stiebel Eltron heat pump water heaters have been the largest seller in Europe for over 35 years.
- Backed by a 10-year warranty.
Certifications:
- Intertek ETL Listed, Certified to ANSI/UL Std. 174 & 1995 and Conforms to CAN/CSA Std. C22.2 No. 110-94 & 236-05.
- WQA Tested & Certified to NSF/ANSI 372 for lead-free compliance.
- ENERGY STAR rated for high efficiency.
Contact: 800.582.8423 | www.stiebel-eltron-usa.com
How the Accelera® Heat Pump Works
An Accelera® unit functions similarly to an air conditioner but transfers heat into the water tank instead of outdoors, making it significantly more efficient than other water heater types.
The process involves:
- A fan draws room air through an evaporator containing liquid refrigerant.
- The refrigerant extracts heat from the ambient air, evaporates, and turns into a gas.
- This warm gaseous refrigerant is compressed, increasing its pressure and temperature.
- The hot refrigerant then flows through a condenser wrapped around the water tank, transferring its heat to the water.
- The refrigerant cools, becomes a super-cool liquid, and passes through an expansion valve, ready to repeat the cycle.
This system uses environmentally-friendly R134a refrigerant.
[Diagram illustrating the Accelera® heat pump cycle, showing the flow of refrigerant through the evaporator, compressor, condenser, and expansion valve, and its interaction with ambient air and water. Key elements include: Ambient Air providing energy, Evaporator, Compressor, Condenser, Expansion Valve, Hot Water Outlet, Cold Water Inlet, and the states of the refrigerant (liquid, gaseous, super-cooled liquid). It also shows the output of Colder Dehumidified Air.]
In warm climates, the Accelera® can be installed in a garage, utilizing outside air. Indoors, it can assist with air conditioning. In cooler climates, placement in a basement allows it to act as a dehumidifier, providing hot water at a discount and a drier basement.
State and Local Rebates & Incentives are available. For up-to-date details, visit the U.S. Dept. of Energy's Database of State Incentives for Renewables & Efficiency website: www.dsireusa.org.
[Diagram of the Accelera® unit's internal components: A heavy-duty, quiet fan draws WARM AIR IN. Sound-deadening insulation surrounds the unit. A Rolling piston compressor motor ensures high efficiency & reliability. The unit expels COOL, DEHUMIDIFIED AIR OUT. Superior insulation minimizes stand-by losses. A large wrap-around aluminum condenser prevents refrigerant contamination and hard water issues. The glass-lined tank ensures long life & hygienic conditions. Cold water remains at the bottom for maximum efficiency. A single, specially engineered, low-wattage backup element is placed at the top of the tank near the hot water outlet for comfort during high demand.]
Key Features and Design
Digital Display: Features a simple, user-friendly menu for operation and access to performance information, including total hot water volume. The Accelera® is "smart meter" ready.
Easy Access for Service: The entire top of the unit can be quickly removed for servicing from all sides.
Redesigned Airflow: Air intake and exhaust are angled for installation in compact spaces. Noise is reduced by separating airflow from the refrigerant loop and increasing fan diameter.
Advanced Anode Protection: Equipped with an electronic anode for maintenance-free corrosion protection, using only the necessary current.
Condenser Design: The roll-bond wrap-around condenser prevents refrigerant contamination and mitigates hard water problems, contributing to energy efficiency.
Evaporator Coating: Protects against corrosion and allows quick water drainage, enhancing airflow and heat transfer. It is self-cleaning, eliminating the need for a filter. Dual-path refrigerant flow ensures performance in both cold and warm climates.
Cold Water Inlet Design: Prevents incoming cold water from cooling the hot water in the tank during a draw, maximizing the volume of hot water available without relying on the booster element. This also helps maintain heat pump efficiency.
Large Tank + Single Heating Element: The Accelera® 300 E features an 80-gallon tank, and the Accelera® 220 E features a 58-gallon tank. These sizes are optimized for household demand and heat pump efficiency. A single, top-mounted booster element provides backup heat for high demand, ensuring comfort without sacrificing efficiency.
Efficiency and Performance:
- Reduces hot water costs by up to 80%.
- Optimal storage capacity and design minimizing booster element usage for high efficiency and low operating cost.
- Engineered for efficiency in a wide range of climates, with a Coefficient of Performance (COP) typically between 3-6.
- Operates on 240V with a single 15 A circuit breaker.
[Graph showing the Coefficient of Performance (COP) for Accelera® 220 E and 300 E models as a function of ambient air temperature, measured according to EN 255.3 at 70% relative humidity, based on 59°F / 15°C cold water temperature. The graph displays COP values from 1 to 8 against ambient temperatures from 41°F/5°C to 113°F/45°C.]
[Diagram illustrating the internal components of the Accelera E, including the fan, compressor, condenser, evaporator, and booster element, with labels for air intake, air outlet, hot water outlet, and cold water inlet. It also shows the 58-gallon tank for the Accelera® 220 E and the 80-gallon tank for the Accelera® 300 E.]
Accelera® 220 E: Winner of the world's major prize for innovation (PLUS X AWARD, BEST PRODUCT OF THE YEAR 2013).
Understanding Operating Modes
While Accelera® models are designed for automatic, efficient operation, traditional hybrid heat pump water heaters offer distinct modes:
Hybrid Heat Pump Water Heaters (General Concept)
- Heat Pump Mode: The most efficient mode, relying solely on the heat pump for savings. Requires user selection.
- Hybrid Mode: Utilizes two standard electric elements for fast water temperature recovery, with the heat pump operating once demand is met by electric elements.
- High Demand Mode: Two electric elements activate sooner and stay on longer. The heat pump is disabled, and the unit relies on electric elements. This mode must be enabled for defrost cycles or if the heat pump fails.
- Vacation Mode: Maintains a very low temperature in the tank, reheating the water before the user returns. It keeps water hot for up to a 2-week vacation for less than $4.
Accelera® Heat Pump Water Heaters (Integrated Efficiency)
The Accelera® is engineered to satisfy approximately 90% of hot water needs using the heat pump alone. It is designed to work harmoniously without requiring users to select specific modes for comfort and savings.
- Main Setting: Operates primarily on the heat pump, with a specially designed electric "booster" element at the top for high demand, engineered to run minimally.
- Automatic Operation: Designed for seamless comfort and savings without user intervention. A user-accessible booster function engages for extraordinarily high demand.
- Defrost Cycle: The Accelera® heat pump does not need to be disabled for a defrost cycle.
- Vacation Mode: The super-insulated tank keeps water hot efficiently during extended absences.
Stiebel Eltron designs its heat pump water heaters for efficiency, prioritizing the heat pump over backup elements. Larger tank capacities (58 gallons for the 220 E, 80 gallons for the 300 E) maximize the use of heat pump-generated hot water. Super-insulation minimizes standby energy losses.
Household Recommendations and Potential Savings
| Model | Household Size Recommendation | Annual Savings* |
|---|---|---|
| Accelera® 220 E | 2-3 people (possibly 4) | $250 – $490 |
| Accelera® 300 E | 3-5 people (possibly 6) | $370 – $740 |
* Savings are based on Energy Star estimates for heat pump water heaters.
Technical Data
| Model | Accelera® 220 E | Accelera® 300 E |
|---|---|---|
| Item no. | 233058 | 233059 |
| Tank capacity | 58 gal (220 l) | 79.8 gal (302 l) |
| Energy Star Energy Factor | 3.05 | 3.39 |
| DOE est. annual energy usage | 1040 kWh/yr | 1289 kWh/yr |
| First hour rating | 50.3 gal (190.4 l) | 74.2 gal (280.8 l) |
| Max. DHW temperature | 149°F (65°C) | |
| Max. avail. amount of 104°F (40°C) DHW | 106 gal (400 l) | 147 gal (560 l) |
| Heat-up time (59°F ambient air temp.) | 6.98–8.70 hr | 9.75 hr |
| Heat-up time (44°F ambient air temp.) | 10.02–11.97 hr | 13.41 hr |
| Voltage / Frequency (Single phase) | 220–240 V / 60/50 Hz | |
| Required circuit breaker | 15 A, Type C | |
| Maximum power draw | 2150 W | |
| Rated power, booster element | 1500 W | |
| Sound pressure level at 3.3 ft / 1 m* | 52 dB(A) | 60 dB(A) |
| Sound power level* (EN 12102) | 60 dB(A) | |
| Operating temperature range | 42–108°F (6–42°C) | |
| Max. permissible operating pressure, cold water/DHW | 116 psi (0.8 MPa) | |
| Refrigerant | R134a | |
| Height | 60¹³/₁₆" (1545 mm) | 75¼" (1913 mm) |
| Diameter | 27³/₁₆" (690 mm) | 26" (660 mm) |
| Empty weight | 264.5 lb (120 kg) | 297.6 lb (135 kg) |
| Full weight | 748.5 lb (339.5 kg) | 956.6 lb (433.9 kg) |
| Condensate connection | ¾" male NPT to ½" barbed elbow | |
| Water connections | 1" NPT | |
| Type of anode | Impressed current anode | |
* Sound Pressure Level (SPL) measures sound at a distance. Sound Power Level (SWL) is an engineering measurement of emitted sound energy.
[Diagrams showing the front and back views of the Accelera® E models, highlighting features like air discharge, display, air entry, leveling feet, condensate spillover, power cable, condensate drain, opening for PT valve, hot water outlet, and cold water inlet.]
About Stiebel Eltron
Stiebel Eltron has been a world leader in advanced water heating technology for almost 90 years. The company's pursuit of engineering excellence and high-quality manufacturing results in products that meet the highest expectations for performance and reliability.
[Image of Stiebel Eltron's plant in Holzminden, Germany.]
Stiebel Eltron also offers a range of other energy-saving water heating solutions, including:
- Tankless Water Heating: Efficient electric tankless water heaters (point-of-use and whole house).
- Renewables: Systems for solar thermal domestic hot water and radiant floor heating, including collectors, storage tanks, and pump stations.
Contact Information:
Stiebel Eltron USA
17 West Street
West Hatfield, MA 01088
TOLL FREE: 800.582.8423
PHONE: 413.247.3380
FAX: 413.247.3369
Email: info@stiebel-eltron-usa.com
Website: www.stiebel-eltron-usa.com
Specifications may change without notice due to continuous process of engineering and technological advancement.
