Look at the room first
Measure floor area and ceiling height. Note direct sunlight, glazing, shading and heat-producing equipment. A home office under the roof has different cooling needs from a shaded bedroom of the same size.
Plan a route for the heat to escape
A compressor-based portable air conditioner rejects heat outdoors. Its exhaust hose and window kit are part of the installation. A water-based evaporative cooler works differently and is not a substitute for an air conditioner. Check compatibility with casement, tilt-and-turn or sliding windows before buying.
Compare the complete setup
Look at cooling capacity, electrical input and noise figures measured on a comparable basis. Include the window kit, dimensions, weight, condensate handling and filter access in your checklist. Castors help on one floor; carrying a unit up stairs is another matter.
Keep heat out before cooling
Close external shading before sunlight heats the glass. Ventilate when it is cooler outside, then close windows during cooling. Treating one clearly defined room is more predictable than trying to cool an entire flat through open doors.
Sources and methodology
These sources explain the technical context. They do not validate FREATH ONE or our calculator assumptions.
U.S. Department of Energy — Portable Air ConditionersOFEN / BFE — Étiquette-énergie / Energieetikette