Question: De Dietrich Remeha, is one of Europe's biggest manufacturers and distributors of domestic and commercial water and space heating systems, in July 2009, when heavily laden with debt, which of Europe's largest manufacturers and distributors of domestic and commercial water and space heating systems, agreed to merge with them? 

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BDR Thermea: The BDR Thermea Group is a European manufacturer of domestic and industrial heating appliances.  The firm was created by the merger of Baxi and De Dietrich Remeha in 2009.  Based in Apeldoorn, the Netherlands BDR Thermea provides heating and hot water products for UK, France, Germany, Spain, The Netherlands and Italy and has strong positions in the rapidly growing markets of Eastern Europe, Turkey, Russia, North America and China.  In total BDR Thermea operates in more than 70 countries worldwide.

Warm Air Research House: The Warm Air Research House is a historic house and research facility located at 1108 W. Stoughton St. in Urbana, Illinois.  Built in 1924, the house served as a warm-air heating research facility administered jointly by the National Warm-Air Heating and Ventilating Association and the University of Illinois Department of Mechanical Engineering.  Prior to the 1920s, the American heating industry had few formal testing procedures for their products, and home heating through warm-air ventilation ducts was still considered a novel concept.  The National Warm-Air Heating and Ventilating Association began to test heating methods and systems in the Department of Mechanical Engineering's laboratories, but it eventually needed a model house in which to test its domestic heating systems.  The two organizations commissioned the large Colonial Revival residence, which was designed by architect Loring Harvey Provine and graduate student Clarence Andrew Kissinger.  Beginning in 1932, research on air conditioning and cooling systems was also conducted in the house.  Following World War II, the facility became less useful due to the shrinking size of new American homes, and the university sold the house in 1946.  Some of the technologies developed in the house include storm windows, forced-air heating, and heating duct size and positioning.

District heating: District heating (also known as heat networks or teleheating) is a system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating.  The heat is often obtained from a cogeneration plant burning fossil fuels but increasingly also biomass, although heat-only boiler stations, geothermal heating, heat pumps and central solar heating are also used, as well as nuclear power.  District heating plants can provide higher efficiencies and better pollution control than localized boilers.  According to some research, district heating with combined heat and power (CHPDH) is the cheapest method of cutting carbon emissions, and has one of the lowest carbon footprints of all fossil generation plants.  A combination of CHP and centralized heat pumps are used in the Stockholm multi energy system.  This allows the production of heat through electricity when there is an abundance of intermittent power production and cogeneration of electric power and district heating when the availability of intermittent power production is low.

Pellet boiler: Pellet boilers are used as central heating systems for heat requirements (heating load) of more than 3.9 kW (Kilowatt).  But pellet central heating systems are not only used in single or two family homes (up to 30 kW), but also for larger residential or business units with heat requirements of a few hundred kW.  Pellet burner systems run most efficiently at full load and can usually be regulated down to up to 30% of its full capacity.  Since the warm up phase of pellet ovens usually takes longer than for oil or gas firing systems, short burning phases have negative effects on the fuel efficiency.  In order to improve energy efficiency and reduce harmful emissions, pellet ovens are usually combined with buffer systems like water tanks for example.

De Dietrich Remeha: De Dietrich Remeha is one of Europe's biggest manufacturers and distributors of domestic and commercial water and space heating systems.  Headquartered in Apeldoorn in the Netherlands, it was founded in July 2004 after a merger between the Dutch firm Remeha, and the French firm De Dietrich Thermique.  In July 2009, the heavily laden with debt British Baxi group agreed to merge with De Dietrich Remeha, creating the BDR Thermea Group.

Baxi: Baxi is a part of BDR Thermea, one of Europe's largest manufacturers and distributors of domestic and commercial water and space heating systems.

Seasonal thermal energy storage: Seasonal thermal energy storage (or STES) is the storage of heat or cold for periods of up to several months.  The thermal energy can be collected whenever it is available and be used whenever needed, such as in the opposing season.  For example, heat from solar collectors or waste heat from air conditioning equipment can be gathered in hot months for space heating use when needed, including during winter months.  Waste heat from industrial process can similarly be stored and be used much later.  Or the natural cold of winter air can be stored for summertime air conditioning.  STES stores can serve district heating systems, as well as single buildings or complexes.  Among seasonal storages used for heating, the design peak annual temperatures generally are in the range of 27 to , and the temperature difference occurring in the storage over the course of a year can be several tens of degrees.  Some systems use a heat pump to help charge and discharge the storage during part or all of the cycle.  For cooling applications, often only circulation pumps are used.  A less common term for STES technologies is interseasonal thermal energy storage

Rheem: Rheem Manufacturing Company is an American privately held manufacturer that produces residential and commercial water heaters and boilers, as well as heating, ventilating and air conditioning (HVAC) equipment.  The company also produces and sells products under the Ruud brand name.  It is a subsidiary of Paloma Industries.  What became Rheem started in 1925 as a supplier of packaging to the petroleum industry, and is currently headquartered in Atlanta, Georgia in the United States.  The company is one of the largest manufacturers of both water heating and HVAC equipment in the United States, and also produces and markets products in Argentina, Armenia, Australia, Bahrain, Brazil, Canada, Iraq, Kuwait, Mexico, New Zealand, Oman, Qatar, Saudi Arabia, Singapore, UAE, and Ukraine.

Solar power in Canada: Historically, the main applications of solar energy technologies in Canada have been non-electric active solar system applications for space heating, water heating and drying crops and lumber.  In 2001, there were more than 12,000 residential solar water heating systems and 300 commercial/ industrial solar hot water systems in use.  These systems presently comprise a small fraction of Canada’s energy use, but some government studies suggest they could make up as much as five per cent of the country’s energy needs by the year 2025.

Electric heating: Electric heating is a process in which electrical energy is converted to heat.  Common applications include space heating, cooking, water heating and industrial processes.  An electric heater is an electrical device that converts electric current to heat.  The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy.  Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.

Supporting paragraphs: De Dietrich Remeha Baxi
Answer: Baxi