High-Efficiency Solutions for Domestic Hot Water in North America

Domestic hot water (DHW) is one of the most universal—and energy-intensive—daily needs in both residential and commercial buildings. From everyday household uses such as showers, dishwashing, and cooking, to the larger demands of hotels, gyms, and multi-family complexes, DHW production is a cornerstone of building energy systems.

But how is DHW generally produced today in North America? And what are the most efficient and sustainable solutions available?

Traditional Solutions: Electric Water Heaters and Gas Boilers

In today’s North American market, the two most common methods for DHW production are:

1. Indirect water tanks – systems with a storage tank of variable capacity where water is maintained at the desired temperature and then delivered when required. Heating is achieved either through electric resistance elements or combustion systems (condensing or non-condensing) fueled by natural gas or propane.
2. Direct water heaters – on-demand (tankless) systems that heat water instantly at the time of use. In North America, these are almost exclusively combustion-based (condensing or non-condensing), fueled by natural gas or propane.

These products rely on established technology, are relatively inexpensive to purchase, and easy to install. 

Moreover, fossil fuel-fired systems with low efficiency also have a significant environmental impact, due to direct CO₂ and NOx emissions.

The Alternative: DHW Production with Heat Pumps

In recent years, heat pumps have gained a steadily increasing market share. A heat pump recovers renewable energy available in the environment (air, water, or ground) and delivers more useful energy to the building than the system consumes in primary energy.

Applied to DHW production, this results in efficiencies well above 100%, far superior to traditional systems.

Because a heat pump does not operate instantaneously, it is generally applied to storage-based systems (indirect water heaters). Rather than being a limitation, this design is actually an advantage: it allows the heat pump to operate more steadily, reduces on/off cycling, extends service life, and maximizes overall efficiency.

A Winning Combination for North America: Robur GAHP A Plus and Thermo 2000 TurboMax

For the North American market, Robur offers a high-efficiency solution that combines advanced absorption technology with a proven local partner.

• Robur GAHP A Plus – An air-to-water gas absorption heat pump designed to produce heating and DHW while leveraging renewable aerothermal energy. Compared to traditional systems, GAHP A Plus delivers efficiencies up to 140% GUE (Gas Utilization Efficiency), drastically reducing both energy consumption and CO₂ emissions. The technology is particularly well-suited to North American climates, as it maintains high performance even at very low outdoor temperatures—down to -40 °F.
• Thermo 2000 TurboMax – A high-capacity thermal storage tank designed specifically to work with heat pumps and other high-efficiency generators. Available in multiple storage capacities, TurboMax ensures maximum DHW availability even during peak demand, making it the ideal complement to GAHP systems.

Together, GAHP A Plus + TurboMax provide the North American market with a concrete solution to three critical challenges:

1. Reducing energy costs.
2. Cutting greenhouse gas emissions.
3. Ensuring comfort and service continuity at all times.

Conclusions

DHW production is a central issue for building energy efficiency and sustainability.

With proper system design and the support of storage and buffer tanks, heat pumps such as Robur’s GAHP A Plus, combined with Thermo 2000’s TurboMax, deliver an efficient, reliable, and future-ready solution for the North American market.