Project stages



Alba Iulia, RO

Project Details

Vezi galerie foto

The Thermodynamic Solar System  SolarBox-2, solution tested by Delphi Electric company from Alba Iulia, stands out by the fact that it produces continuous hot water, even during the night.

A refrigerant (r134a) circulates at a very low temperature through the solar panel. It captures besides the solar radiation , the air heat in the atmosphere, achieving a very high efficiency of 450% (COP, average performance coefficient of 4.5), that means it can produce an average of 4.5kWh of thermal energy consuming 1kWh of electric power.

It uses a technology based on the principles of thermodynamics, discovered by the French physicist Nicolas Carnot. Thermodynamic Solar panels are able to capture the heat from both the Sun and the environment including when it rains or when it is snowing. System test exceeds the limitations of traditional solar panels and make possible the increase of water temperature.

Because the fluid enters the billboard at very low temperatures (-15 degrees Celsius), it captures the heat from the outside even when there is no sun, heat which is subsequently transferred to the domestic hot water. Ability to capture heat from the environment is mainly assured by solar radiation and ambient temperature, making it superior to other devices with the same purpose and very economical. The system requires no maintenance and is very durable.

The system consists of three main components:

・ solar thermodynamic panels (1 or 2 panels)
・ air / sun-water heat pump of 2,4kW or 4,8kW (thermal)
・ the hot water storage tank.

The installed SolarBox-2 has 2 panels and can heat a 500L boiler in about 7 hours *,
consuming only 0.9kWh. The system has been mounted in tandem with the existing thermal
plant that now has only a backup role.

Current stage: The project is installed and functional from June 15, 2018 and can be seen in “CETATE” kindergarten of Alba Iulia (str. Alexandru cel Bun, Nr. 13), with a capacity of 55 places. The system is operating properly, and the central heating system (natural gas) has not devoted to running, warm water being produced 100% of the thermodynamic system. Existing central heating system now has only a back-up role.

More information about this system, as well as other examples of implementation of thermodynamic solar systems for hot water and central heating, can be found on the website of the company Delphi Electric from Alba Iulia.

SolarBox-2 thermodynamic solar system is dedicated to citizens, in particular children from  “CETATE” kindergarten of Alba Iulia.

Technical specifications

Vezi galerie foto

Thermodynamic Solar Panel is constructed of anodized aluminum, coated with a layer of flexible hidrofobic.

Dimensions: 200x80x2cm, easily transported and installed (8 kg), can be installed in horizontal between 10-85 degrees, roof, wall, ground, etc. Requires no maintenance, and expected duration is 25 years.

Thermodynamic block consists of the compressor, condenser, expansion valve and the control system. Has no fans! The only mechanical item that requires electricity is the compressor highly effective, with a very low power consumption.

Other technical specs:

  • Average thermal power: 4.5 kWh
  • Electric power consumed: 0.9 kWh
  • Hot water temperature: max 55 ° C
  • COP (average performance): 4.5
  • Boiler capacity: 500L
  • Daily heated water volume: 2000L / day
  • Panel parameters: 2m x 0.8m, weight: 8kg
  • Heat pump: 40cm x 40cm x 50cm, weight: 20kg
  • Maintenance: does not require periodic maintenance
  • There is no danger of freezing or overheating of the agent in the panels

Period of use > 20 years.

Vezi galerie foto

General benefits and benefits for “CETATE” nursery, where the system is tested:


  • Hot water 24/24 hours;
  • Savings of up to 85%;
  • Systems of last generation;
  • Works together with Photovoltaic Systems;
  • Producing hot water throughout the year, both day and night regardless of the atmospheric conditions;
  • Low power consumption due to high efficiency (to get a heat output of ~ 1.7 kWh consumed just 0.39 kWh electric energy, the difference being thermodynamics);
  • Easy integration in the architecture of buildings;
  • Refrigerant Circuit the agent is totally separate from the heated water;
  • Maintenance-free;
  • Long life.