Modern wall-mounted units run at 19 to 24 dB(A) on their lowest fan setting, which is quieter than a library. The Mitsubishi Electric MSZ-LN sits at 19 dB(A) and is one of the quietest residential units available. If the unit is going in a bedroom, noise rating should be a deciding factor.
All the systems we install carry an A++ or A+++ energy rating. Running costs for a typical 2.5 kW unit in a bedroom come to roughly £30 to £50 per year depending on usage. Units with inverter compressors adjust their output continuously rather than switching on and off, which keeps consumption low and extends the life of the system.
Every unit we fit runs in reverse cycle, providing heating as well as cooling. In milder months, running the air conditioning as a heat pump is more efficient than a gas boiler for warming a single room.