18000 BTU Mini Split Air Conditioner & Heater A++ Energy Efficient Inverter Split AC

The Costway 18000 BTU split air conditioner is built for large open-plan rooms, covering up to 116m² of cooling and heating from a single A++ inverter wall unit. With a strong SEER of 6.7 and SCOP of 5.3 — the highest in this range — it's the most efficient per BTU, and its 850m³/h airflow and 38.4L/day dehumidification handle big volumes of air with ease. Despite the extra capacity, the silence function still brings noise down to a bedroom-quiet 19dB. Cooling and heating are both rated at 18,000 BTU (5100W / 5200W), and the cooling power input is 1800W, so at full output you'd spend roughly 47p an hour at around 26p/kWh; the inverter trims this considerably once the room is settled. You get 7 modes (cool, heat, dry, fan, auto, sleep, ECO), 4D swing, 5 fan speeds, child lock, self-clean and auto defrost, with a 24-hour timer and 8m remote. It runs on R32 refrigerant. As with all split systems, UK F-Gas rules mean it must be installed and commissioned by a certified engineer — the indoor unit weighs 10kg and the outdoor condenser 22kg, so this is a professional fit, not a plug-in portable.