The tariff classification of a temperature control unit from South Korea

N359553 March 24, 2026 CLA-2-84:OT:RR:NC:N1:103 CATEGORY: Classification TARIFF NO.: 8419.89.9585 Youngtae Kim JangBaek Customs Attorney 4F, 24, Dosandaero38, Kangnam Seoul 06049 South Korea RE: The tariff classification of a temperature control unit from South Korea Dear Mr. Kim: In your letter dated March 9, 2026, you requested a tariff classification ruling on behalf of your client, Techest Co., Ltd. The merchandise under consideration is referred to as an electric chiller, model number LC-8050XC. Although called an “electric chiller” the equipment is a dual-channel temperature control unit used in industrial environments that require precise temperature control, such as during semiconductor and display manufacturing processes. The system circulates coolant through manufacturing equipment or target objects, either removing heat generated during the manufacturing process or increasing the temperature in situations where temperature stability is crucial. The unit features a freestanding enclosure with multiple inlet and outlet ports. Inside the enclosure are a pump, a coolant reservoir, a heated reservoir, a thermoelectric module, a plate heat exchanger, an immersion heater, a pressure gauge, a flow meter, and sensors. This unit measures approximately 780 millimeters in depth, 680 millimeters in width, 505 millimeters in height, and weighs 160 kilograms. The system is connected to a remote controller, which is a separate cabinet that contains an AC power box, a switched-mode power supply, an inverter, a PLC assembly, and other components. The temperature control unit has two independent loops or channels. The first channel is used when a low-temperature process is required while the second channel is used when a high-temperature process is required. In the first channel, temperature control relies on a thermoelectric module block, which consists of multiple thermoelectric modules arranged in layers. When a cooling cycle is required, coolant is pumped to the process equipment to absorb heat. The heated coolant returns and is routed to the thermoelectric module block. This block utilizes the Peltier effect, with a cold side that absorbs heat from the returning coolant and a hot side that transfers heat to process cooling water supplied by the facility. When a heating cycle is required, the polarity of the DC voltage is reversed. In the second channel, temperature control relies on a plate heat exchanger. During a cooling cycle, coolant is pumped to the manufacturing equipment and returns to the heat exchanger, where heat is transferred to a facility-supplied process cooling water circulating through separate channels. When heating is required, such as during start-up or in cold environments, the immersion heater increases the coolant temperature in the reservoir. The heated coolant is then pumped to the manufacturing equipment. In your submission, you suggest that the main unit is classifiable in heading 8419, Harmonized Tariff Schedule of the United States (HTSUS) and the control unit is separately classified in heading 8537, HTSUS. We agree in part. Both units will be imported packaged together in the same shipment and will be used as components in a system that performs a clearly defined function described by heading 8419. As such, they will be classified together as a functional unit. The applicable subheading for the electric chiller system, model number LC-8050XC, will be 8419.89.9585, HTSUS, which provides for “Machinery, plant or laboratory equipment, whether or not electrically heated (excluding furnaces, ovens and other equipment of heading 8514), for the treatment of materials by a process involving a change of temperature such as heating, cooking, roasting, distilling, rectifying, sterilizing, pasteurizing, steaming, drying, evaporating, vaporizing, condensing or cooling, other than machinery or plant of a kind used for domestic purposes; instantaneous or storage water heaters, nonelectric; parts thereof: Other machinery, plant or equipment: Other: Other: Other: Other: For other materials.” The general rate of duty will be 4.2 percent ad valorem. Duty rates are provided for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying duty rates are provided at https://hts.usitc.gov/. This ruling does not address the applicability of any additional duties, taxes, fees, exactions and/or other charges, which may apply to the goods discussed herein. This includes, but is not limited to, tariffs and other duties as provided for in Subchapter III to Chapter 99, HTSUS. Thus, for example, in addition to the classification stated above, the merchandise covered by this ruling may also need to be reported with either the Chapter 99 provision under which an additional tariff applies or one of the Chapter 99 provisions covering exceptions to such tariffs. For further information to assist with the importation process, please refer to the frequently updated Cargo Systems Messaging Service (CSMS) messages at https://www.cbp.gov/trade/automated/cargo-systems-messaging-service and the Trade Remedies page at https://www.cbp.gov/trade/programs-administration/trade-remedies. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist Paul Huang at paul.huang@cbp.dhs.gov. Sincerely, (for) James Forkan Designated Official Performing the Duties of the Division Director National Commodity Specialist Division