--- title: "How to Cool Problem Rooms With a Mini-Split Instead of Overworking Your Central AC" description: "Stop lowering the thermostat to cool one hot room. Learn how a ductless mini-split delivers targeted comfort, reduces energy waste, and eases the load on your central AC." date: "2026-08-10" modified: "2026-08-10" authors: - name: "The Costway Team" job_title: "Partner" link: "https://www.bobvila.com/authors/costway/" url: "https://www.bobvila.com/interior/cool-problem-rooms-with-costway-mini-splits/" categories: - "Cooling" - "Heating & Cooling" - "Interior" - "Sponsored Content" tags: - "Sponsored" --- # How to Cool Problem Rooms With a Mini-Split Instead of Overworking Your Central AC ![Costway Mini Split HVAC Installed Above a Bedroom Window]() *Photo: Courtesy of Costway* If one room in your home always feels too hot or too cold, you're not alone. Adjusting the thermostat to cool a single upstairs bedroom or warm a chilly basement often forces your central HVAC system to work harder, increasing overall energy use while leaving other areas uncomfortable. A ductless mini-split air conditioner offers a more targeted solution, delivering independent climate control where it's needed most. Known for manufacturing practical home solutions beyond furniture, Costway offers energy-efficient [mini-split systems]() designed to improve comfort without replacing an entire HVAC system. ## Where You Might Find Hot Spots at Home Some rooms are simply trickier than others for a central HVAC system to keep comfortable. For example, upstairs bedrooms naturally retain more heat as warm air rises. Electronics and activity in home offices and gyms tend to make these rooms warmer than others on the same level. Finished attics, converted garages, sunrooms, and enclosed patios may not be connected to existing ductwork. Likewise, additions, guest suites, workshops, and ADUs often fall outside the home's original heating and cooling zone. When any of these spaces become consistently uncomfortable, a ductless mini-split can allow you to set a temperature specifically for this room without forcing your central HVAC system to compensate for the entire house. ## A Smarter Way to Cool Problem Rooms As the name suggests, a ductless mini-split doesn't rely on existing ductwork. Instead, installation typically requires only a small opening for the refrigerant lines, drain, and electrical connections, making it a practical option for additions, renovated spaces, and other hard-to-condition rooms. For example, the [Costway Airtural Series 18,000 BTU Mini-Split Air Conditioner and Heater]() combines targeted heating and cooling with inverter technology, ENERGY STAR certification, and low-noise operation to help maintain consistent comfort while using energy efficiently. Like other heat-pump mini-splits, it provides year-round heating and cooling while reducing the workload on a home's central HVAC system. Professional installation is recommended to ensure the system is properly sized, safely connected, and operating at peak performance. ![Costway Mini Split HVAC installed in an Office Addition]() *Photo: Courtesy of Costway* ## How to Choose the Right Mini-Split for Your Space When comparing mini-split systems, start with proper sizing. Capacity is measured in BTUs (British Thermal Units), and the right unit depends on factors such as room size, ceiling height, insulation, sun exposure, and heat-producing electronics. An oversized or undersized system can reduce both comfort and efficiency. For homeowners seeking greater energy efficiency and year-round comfort, the [Costway SEERXtreme Series 18,000 BTU, 25 SEER2 Mini-Split Heat Pump]() combines inverter technology with a 25 SEER2 rating for efficient, consistent heating and cooling. It's designed to heat in outdoor temperatures as low as -15 degrees Fahrenheit and cool in temperatures up to 126 degrees Fahrenheit, though performance varies by installation, climate, and room conditions. Costway backs its mini-split systems with an 8-year compressor warranty and a 5-year parts warranty, and Costway customer service is available to assist homeowners throughout the buying process. ## What Homeowners Are Saying About Costway Mini-Splits Features and specifications can help narrow your options, but real-world experiences are also worth considering. Verified customer reviews of Costway mini-split systems frequently mention quiet operation, consistent heating and cooling performance, and convenient Wi-Fi controls. Individual experiences vary based on installation, room conditions, and climate, but reading verified reviews can provide additional insight into everyday performance. Costway currently works with a professional installation team in California to help customers arrange installation and plans to expand this network over time, with the long-term goal of serving customers across the United States. ## Final Thoughts Living with one room that's always too hot or too cold doesn't mean you have to replace your entire HVAC system or keep lowering the thermostat. A properly sized ductless mini-split can deliver targeted, year-round heating and cooling while reducing the strain on your central HVAC system. The result? A practical solution for problem rooms without conditioning the entire house.