Aircon

E30s are cool. But they won't keep you cool, and if you've got a tin-top in Diamond Metallic Black, then come those summer months you're really going to want something to lower the temperature in the cabin. That's where Aircon comes in.

Overview

Aircon was fitted as an optional extra to E30s as early as 1984, and the system remains largely the same throughout the E30 production run. The system is based around a sealed refrigerant gas, just like your fridge at home. I won't explain the science, but as the refrigerant is converted from a gas to a liquid it gains heat; as it goes back to a gas it loses heat and cools, and it is this cooling effect we make use of. It's therefore essential that our system be completely sealed, to keep the refrigerant inside.

The system uses a number of components to compress, liquify, filter and evaporate the refrigerant. Expansion_Valve|Valves regulate the flow of refrigerant through the pipework, and the whole system is controlled from a switch on the dashboard. A pressure switch monitors the condition of the coolant and determines whether or not the compressor needs to be engaged; if required, the clutch locks to drive the compressor.

Since its introduction, the original refrigerant has been made illegal for environmental reasons in the EU and many other states. A conversion kit to a more modern coolant is available from BMW.

Components

Refrigerant

The original refrigerant gas for the aircon system was R-12; one of the more aggressive CFCs. It was banned in 1994.

However, since the E30 was still being produced in some markets in 1994, the final volume of aircon-equiped vehicles received a conversion kit to the less malevolent R-134a. Since the refrigerant in all E30s will be due for replacement (known as "recharging" the system), it is essential to convert your aircon over to an R-134a compatible system.