Air conditioner

Abstract

An air conditioner comprises an evaporator for transferring heat from air to a refrigerant gas, a temperature sensor for sensing a temperature associated with the evaporator, a compressor for compressing the refrigerant gas, an electric motor for driving the compressor, and a controller for controlling the speed of the motor, wherein the controller is responsive to the temperature sensor.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to air conditioning and in particular, to air conditioners. [0002] Although the invention will be described with particular reference to an air conditioner for a boat, it will be appreciated that the air conditioner according to the present invention is not limited to use on a boat. For example, the air conditioner may be used for air conditioning a truck cabin, the interior of a racing car, a crane cabin, or the interior of a house. BRIEF DISCUSSION OF THE PRIOR ART [0003] Most air conditioners need to be powered by an AC electrical power supply such as a mains electrical power supply. However, such air conditioners are not suitable for use on boats, racing cars, crane cabins or remote housing where mains power is not available. [0004] Car air conditioners are known which have a particular type of compressor called a “scroll” compressor. The scroll compressor is normally coupled to an engine drive shaft of the ca...

AI Technical Summary

Benefits of technology

"The present invention provides an air conditioner that can be powered by a battery and has a reduced amount of electricity consumed. This is achieved by controlling the speed of the electric motor, which is responsive to the temperature sensor. The air conditioner includes an evaporator for transferring heat from air to a refrigerant gas, a compressor for compressing the refrigerant gas, an electric motor for driving the compressor, and a controller for controlling the speed of the motor. The electric motor is preferably a brushless DC electric motor with multiple phases. The air conditioner also has a position sensor for sensing the position of the motor armature. The electric motor is preferably a permanent magnet electric motor with skewed-type magnets to prevent cogging. The electric motor is adapted to operate from a supply voltage in the range of 12V-48V. The air conditioner also includes a toothed pulley mounted on the drive shaft of the motor and a toothed drive belt trained around the pulleys."

Problems solved by technology

However, such air conditioners are not suitable for use on boats, racing cars, crane cabins or remote housing where mains power is not available.

The disadvantage of using the car engine to drive the air conditioner compressor is that doing so reduces the performance of the car because some of the power which is produced by the engine is diverted from rotating the wheels of the car to driving the compressor.

While this is normally acceptable for ordinary cars, it is normally not acceptable for racing cars.

However, these types of air-conditioners typically draw an enormous amount of electrical current (typically over 100 A) which means that if they are powered by a battery, the battery will usually run out of charge very quickly.

A problem with this is that when the motor is turned on, it is normally run at its maximum speed so that it consumes a lot of power.

This is not desirable if the air conditioner is being powered by a battery.

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