HortiMaX participates in unique geothermal energy project in South Korea

When you think of South Korea, you don’t normally envision two ultra-modern glasshouse facilities specialising in sweet pepper production. Although these facilities may seem pretty unremarkable in most ways, they’re nonetheless unique since they’re the first glasshouses to be successfully heated by geothermal energy in South Korea. 

HortiMaX collaborated with its Korean dealer Daeyoung GS, owned by Mr Young-ho Cho, on this project. While Daeyoung designed the system used to extract the geothermal energy, HortiMaX designed the entire control system based on its well-known MultiMa computer. The system required 115 underground heat exchangers to be installed at a depth of 200 metres. 40mm polyethylene pipes were inserted into the drill shafts, allowing the heat exchange to occur, which raises the water temperature from 10˚C to 15˚C. An electric heat pump is then used to further increase the temperature of the water, until it reaches 48˚C, after which it's stored in a storage tank.

The operation of a heat pump is comparable to a fridge. A fridge extracts heat from the air inside, which it then expels to keep the contents of the fridge cool. A heat pump works in a similar way, except that it cools or heats water rather than air. In summer, the cold water is used and the hot water is stored underground, while in winter, this process is reversed and the hot water is used. 

The facilities are equipped with ten heat pumps, which are switched on in two phases. If the heat content of the water in the storage tank drops below a pre-set level, the pumps are activated. In this way, the tank is used to compensate for the difference in heat production and consumption. Since the hot side of the heat pumps is used in winter and the cold side in summer, the operation of the heat pumps is reversed twice a year.

At Artfarm, the four glasshouse compartments are heated or cooled using air-conditioning units. Each compartment is equipped with two air-conditioning units that are activated based on temperature and/or humidity. The units obtain their heating or cooling water from the storage tank. The water-to-air heat exchangers then deliver the heated or cooled air under the plants using perforated distribution tubes.

Artfarm had two important reasons for switching from an oil-fired heating system to one running on geothermal energy: First, electricity (used to power the heat pumps, for instance) is much cheaper than oil in South Korea, resulting in a cost reduction of no less than 70%! Second, the use of geothermal energy has enormous environmental benefits. The geothermal system was put into operation earlier this year and is running at peak performance. HortiMaX and Daeyoung have now embarked on a second geothermal energy project in South Korea.