An air compressor comprising an air intake unit for importing air at atmospheric pressure. A cylinder means for compressing air; a storage tank; a first airline extending between the air intake unit and the cylinder means, the first airline being configured to convey air from the air intake unit into the cylinder means; a second airline extending between the cylinder means and the storage tank, the second airline being configured to convey compressed air from the cylinder means to the storage tank; a motor connected to the cylinder means, configured for driving the cylinder means; a valve inserted into the first airline, the valve being configured to be adjustable between a closed condition and an open condition.