On a 100-point scale, considering the installation cost, I'd give it about 80. If worries about the progressive tax ease, it's 90, and with government support it's 100. I thought connecting four air conditioners would be noisy, but it isn't, and the hot water works well. (Yang Chang-hee, 74, piloting Samsung Electronics' EHS All-in-One at a home in Donam-dong, Jeju City)
In Jeju, liquefied petroleum gas (LPG) is so expensive that in winter we could hardly turn on the boiler and only warmed the air with an electric heater. Keeping heating costs to about 200,000 won a month for both electricity and LPG made it very cold. We haven't gone through a winter with the heat pump yet, so it's hard to evaluate precisely, but I thought an air-source heat pump was a perfect fit for our home, so I applied right away. (Kim Eun-ae, 54, using the EHS heat pump boiler at the first household in the Jeju heating electrification program)
A two-story detached house in Donam-dong, Jeju City, visited on the 10th of this month. Beyond the low wall with a view of Hallasan, an unfamiliar machine sat on one side of the yard. It was an outdoor unit of Samsung Electronics' EHS All-in-One, larger than a typical household air-conditioner outdoor unit. Although the house was completed in 1992, there were no obvious signs that the building's exterior had been significantly altered to bring in new heating and cooling equipment.
The equipment may still be unfamiliar in Korea, but inside, the living environment was not much different from homes that use separate air conditioners and boilers. Four common wall-mounted air conditioners hung on the walls—the kitchen and master bedroom on the first floor, and the living room and master bedroom on the second floor. Cold air blew from the air conditioners, and at the same time warm water flowed when the faucet was turned on. Using cooling and hot water together did not require stopping either one.
Samsung Electronics is piloting the EHS All-in-One at this house ahead of its domestic launch. In existing houses, an air-conditioner outdoor unit is used for cooling, and a boiler for floor heating and hot water. The EHS All-in-One combines an air-to-air (A2A) system that directly heats and cools the air and an air-to-water (A2W) system that heats water for floor heating and hot water into a single outdoor unit. At the Donam-dong house, one 16 kW outdoor unit was connected to four wall-mounted air conditioners and the floor heating and hot water system.
Samsung Electronics finished installation at the end of June and began the pilot in July. Over about a year through next summer—covering heat waves, cold snaps and the shoulder seasons—it plans to assess cooling, heating and hot water performance, energy use, and usability for actual residents. The goal is to verify whether lab results hold in real homes where living patterns and weather change frequently.
A single large outdoor unit installed outside the dwelling handled multiple indoor units plus heating and hot water, yet even up close it did not seem particularly louder than a typical household air-conditioner outdoor unit. Yang said, "I thought the noise would be severe because it's a large capacity that connects four air conditioners at once, but it wasn't," adding, "In the past I had to check when the oil would run out and turn the boiler on and off to use hot water, but now I just set the temperature and it runs on its own, which is convenient."
Samsung Electronics first launched the EHS All-in-One in Europe in March and is preparing a product tailored to Korea's housing environment. It has also installed the EHS All-in-One at Samsung C&T's Residential Performance Research Center in Yongin. In an environment similar to an actual apartment, one floor runs a conventional boiler and system air conditioner, while another runs the EHS All-in-One to compare cooling, heating and hot water performance and energy consumption.
◇ Heating with electricity instead of LPG… visiting Jeju's first household
Samsung Electronics is participating in Jeju's heating electrification program and supplying the EHS heat pump boiler. Instead of LPG or oil boilers that burn fossil fuels, it uses heat from outdoor air and electricity to provide heating and hot water. The first installation took place in a detached house in Aewol, Jeju, in June.
Jeju Aewol's first household was a two-story detached house with an ocean view beyond a basalt stone wall. A heat pump larger than a typical air-conditioner outdoor unit sat against the dwelling's exterior wall inside the stone fence, and a plaque by the entrance read "First installation household of the heating electrification program." If the All-in-One uses a single outdoor unit for cooling, heating and hot water, the EHS heat pump boiler installed here replaces the existing LPG or oil boiler to handle floor heating and hot water.
Opening the door to a separate panel space next to the outdoor unit revealed a white water tank about as tall as an adult woman, thick red and blue piping, a pump and a pressure gauge packed inside. Compared with a standard household boiler, the visible outdoor equipment was larger and more complex. Still, the in-home user experience was not much different from before. In fact, it was more convenient because a 7-inch touch display on the wall showed the current water temperature, operating status and monthly energy use. The product also connects to Samsung Electronics' SmartThings smart home platform so heating and hot water can be controlled by smartphone.
Kim's family said they installed the product at the end of June to ease the burden of heating costs. Kim said, "To properly warm the floor, we had to run the boiler for a long time, but worries about the expense kept us from doing so." In their two-story, 30-pyeong home, they kept combined electricity and LPG costs to around 200,000 won a month, but had to give up keeping the interior sufficiently warm. Some detached houses in Jeju are not supplied with city gas, so they use LPG or oil boilers. In areas with fewer households and more detached houses, LPG unit prices are especially higher.
They have not yet gone through a winter with the heat pump. For about a month after installation, they mainly used hot water. Kim said, "We're using hot water in exactly the same way as before," adding, "Even when the three of us used hot water simultaneously upstairs and downstairs, there was no shortage or sudden bursts of cold water."
The outdoor unit was not very loud either. Samsung Electronics applied a structure inspired by the Eurasian eagle-owl's wings to the outdoor unit fan, reducing minimum operating noise to 35 dB.
◇ Hot water from heat air conditioners used to waste… up to 5 times heating per 1 unit of electricity
A heat pump's basic principle is the same as an air conditioner's. Instead of igniting gas or oil to generate heat, it compresses and expands refrigerant to move heat that exists inside and outside the home. In summer it expels indoor heat outside; in winter it draws in heat from outdoor air.
Shin Moon-sun, an executive director in Samsung Electronics' Digital Appliances (DA) Division, said, "In a heat pump, 'pump' means moving energy," adding, "Unlike burning fossil fuels to create heat, it gathers and moves heat from outside, so it can achieve high efficiency."
Samsung Electronics' EHS heat pump boiler posts a seasonal coefficient of performance (SCOP) of 4.9 at a 35-degree outlet-water condition. That means if you input 1 unit of electricity and add the heat drawn from outdoor air, you can produce nearly five times as much heating energy.
The EHS All-in-One adds cooling to this. Its standout feature is "heat recovery." The hot air blowing from an air-conditioner outdoor unit in summer is heat removed from indoors. Conventional air conditioners simply vent it outside. The EHS All-in-One recovers the heat generated during cooling by exchanging it back into water to make domestic hot water.
Samsung Electronics said that compared with installing an air conditioner and a heat pump separately, this kind of heat recovery can cut summer electricity use by about 20%. Shin said, "In summer, even without separate heating, you can make warm water by running the air conditioner and using the heat that would otherwise be wasted."
◇ Storing surplus electricity as "hot water"… VPP linkage in Jeju
The push to expand heat pumps in Jeju is not only about cutting heating bills. With a high share of solar and wind, Jeju sometimes produces more electricity than it consumes. How to use the surplus power is an important question.
Samsung Electronics is testing a method that uses heat pumps to convert this electricity into thermal energy and store it. The typical approach is "thermal storage." When electricity is in surplus, the heat pump runs in advance to heat water in a large tank, which is then used for floor heating and hot water when needed. Instead of storing electricity in a battery, the energy is kept as hot water.
Samsung Electronics is also testing linking virtual power plants (VPP) with heat pumps. A VPP controls dispersed solar and wind generation and power-consuming devices across regions as if they were a single power plant through information and communications technology. When power is in surplus, the VPP sends an operation signal to the heat pump to preheat the water.
Thermal storage is not the most efficient for every dwelling. Even if a tank is insulated, some heat escapes over time when water is preheated to high temperatures. The alternative "alternating mode" switches the water path—to the hot water tank when hot water is needed, and to floor heating when heating is needed—so only the required amount is heated at the time.
◇ The 14 million won installation cost is key… "Still difficult without subsidies"
Price is the biggest hurdle. Through Jeju's heating electrification program, the product and installation expense for Samsung Electronics' EHS heat pump boiler is about 14 million won. With 70% covered by the government, consumers pay about 4.2 million won. Considering a standard boiler installation costs around 1 million won, the upfront burden is several times higher even with subsidies.
The government has set a goal of distributing 3.5 million heat pumps by 2035 to cut greenhouse gases by 5.18 million tons. Shin said, "Without subsidies, the market would be hard to sustain at the current level of industrial capacity," adding, "As the market grows and manufacturers gain economies of scale, the share of subsidies should come down."