Portable Air Conditioning

A portable air conditioner is typically mounted on wheels and can be easily transported inside a home, leisure area, retail area or workspace. They are currently available with capacities of about 6,000 to 60,000 BTU/h (1,800 to 18,000 watts output) and with or without electric resistance heaters. Portable true air conditioners come in two forms, split type: A unit with an indoor and outdoor unit connected by a length of 1-2 hose (typically up to 35m long) and hose type: a single unit with a hose (typically 4 wide) that exhausts the hot air. Evaporative coolers, sometimes called conditioners, are also portable.

Air-cooled portable air conditioners are compressor-based refrigerant systems that use air to exchange heat, in the same way as a car or typical household air conditioner. With this type of system the air is dehumidified as it is cooled. They collect water condensed from the cooled air, and produce hot air which must be vented outside of the cooled area (they transfer heat from the air in the cooled area to air which must be vented).

Hose systems, which can be Air-to-Air and Monoblock, are vented to the outside via air ducts. The "monoblock" version collects the water (collected from the air) in a bucket or tray and stops when full. The Air-to-Air version re-evaporates the water and discharges it through the ducted hose, and can run continuously.

A single-duct unit draws air out of the room to cool its condenser, and then vents it outside, this air is replaced by hot air from outside or other rooms. A dual-duct unit draws air from outside to cool its condenser instead of from inside the room, and thus is more efficient than most single-duct units.

Modern units run on approximately 1 to 3 ratio i.e., to produce 3kW of cooling they will use 1kW of electricity.

Evaporative coolers, sometimes referred to as air conditioners, do not have a compressor or condenser, instead water is evaporated and the cooled vapour is forced in to the area via the use of a fan. Evaporating water absorbs a significant amount of heat, the latent heat of vaporisation, cools the air (humans and other animals use the same mechanism to cool themselves by sweating). They have the advantage of needing no hoses to vent heat outside the cooled area, making them truly portable and use much less energy than true air conditioners.