All Case Studies
Project Brief
North America
Claire Drew
Garth Schultz
May 15, 2026
Commercial Building
Domestic hot water
Integrated Thermal Storage System
Hydronic Heat Pump Integration
Thermal Energy HQ developed a scalable thermal energy solution combining Apollo EVI inverter air-to-water heat pumps with modular ThermalTank thermal storage technology to improve energy efficiency, reduce peak electrical demand, and provide long-duration thermal energy storage for hydronic heating systems.
The project focused on integrating high-performance EVI inverter heat pump technology with atmospheric thermal storage tanks capable of storing large amounts of thermal energy while minimizing standby losses. The system was engineered for multi-function operation including domestic hot water generation, hydronic space heating, and future cooling integration.
The Apollo EVI heat pump platform supports operation in extreme climates down to -30°C outdoor temperatures while producing supply water temperatures up to 131°F and beyond depending on system configuration.
The ThermalTank platform provided modular thermal storage ranging from 350 to 700 gallons with high insulation values and minimal daily temperature loss.
Many commercial and institutional buildings face increasing utility demand charges and aging boiler infrastructure that is expensive to maintain and inefficient to operate. Traditional hot water systems often cycle frequently, experience standby losses, and struggle to integrate renewable or off-peak energy sources effectively.
The project required a solution capable of:
The design team also needed to minimize mechanical room installation complexity while maintaining serviceability and long-term operational reliability.
The solution utilized Apollo EVI DC inverter air-to-water heat pumps paired with ThermalTank atmospheric thermal storage systems.
The Apollo EVI systems incorporate enhanced vapor injection (EVI) compressor technology designed for low ambient operation and improved cold-weather efficiency. The systems support heating, cooling, and domestic hot water operation through hydronic distribution systems.
The selected heat pump platform included:
Thermal storage was provided through ThermalTank systems engineered with:
The 350-gallon ThermalTank configuration alone provides approximately 54.6 kWh of thermal energy storage at a 35°C temperature differential.
The system architecture allowed heat generation to occur during lower utility rate periods while stored thermal energy could later satisfy domestic hot water and space heating demand.
The installation emphasized proper hydronic integration, insulation practices, and control coordination between the heat pumps and storage systems.
Key implementation considerations included:
The Apollo Hydro Smart Station simplified field installation through integrated hydronic components including:
The modular ThermalTank design also improved logistics and installation access in constrained mechanical spaces by allowing efficient shipping and rapid assembly.
The integrated thermal storage and heat pump system delivered several operational and long-term advantages:
The thermal storage platform also supports demand management strategies and future grid-interactive operation by shifting thermal production away from high-rate utility periods.
Because the ThermalTank system is non-corrosive and atmospheric, lifecycle expectancy exceeds many traditional pressurized steel storage tanks while allowing individual component replacement rather than full system replacement.
The modular approach additionally provides flexibility for future expansion without requiring full system redesign.
By combining advanced EVI inverter heat pump technology with modular thermal energy storage, Thermal Energy HQ created a scalable hydronic energy platform capable of improving efficiency, reducing operational costs, and supporting future electrification initiatives.
The project demonstrates how thermal batteries and modern heat pump systems can work together to create resilient, flexible, and high-performance energy infrastructure for commercial and institutional applications.
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