Air Conditioning Basics

There are six basic components needed to complete an air conditioning installation: evaporator, compressor, compressor bracket, hose kit (A/C hose, fittings, crimp ferrules, o-rings and drier with drier brackets), condenser and safety switch. The following is a brief description of each of these components:

Evaporator
The evaporator is the unit that mounts inside the vehicle on the firewall. This component contains an A/C and heater coil similar to a radiator in which liquid refrigerant and engine coolant travel through. The blower forces air across the coil, through duct hose and out vents. An important aspect of evaporators is the coil size. Since a coil can only process a specific amount of air at any time, it is important that the coil size be adequate for the interior size of the vehicle (i.e. larger vehicles require larger coils/evaporators). Hot Rod Air uses the largest A/C and heater pass coils available for maximum performance.

Compressor
The primary compressor used in Hot Rod Air systems is the Sanden 508 compressor. This small bodied aluminum compressor features five pistons for smooth operation. The advantage of the 508 is it provides ample capacity for the majority of performance vehicle applications but requires very little horsepower to operate. Sanden 505, 510 and 709 and 7176 series are also used in special applications depending on condenser size and space available. Although the 508 is the preferred compressor for Hot Rod Air systems, ask our sales staff about adapting stock GM and Ford compressors to your system.

Engine Bracket
Hot Rod Air has a complete selection of quality brackets for mounting accessories to a number of different engines by various manufacturers. Whether you prefer the simple functionality of steel or the high tech show look of billet aluminum, Hot Rod Air, has brackets not only for compressors but also matching brackets for alternators as well. We also offer a universal bracket with which a bracket for special applications can be fabricated.

Hose Kit
In order to maintain the required pressures, an air conditioning system must implement hoses with crimped fittings. There are three different sizes of hose used: #8 from the compressor to the condenser, #6 from the condenser through the drier to the evaporator and #10 from the evaporator back to the compressor. Due to a variety of hose layouts, Hot Rod Air offers universal hose kits that allow the builder to make hoses to his own length specifications. Kits are available with either barb or beadlock style fittings.

Drier
The drier mounts into the #6 high pressure line between the condenser and the evaporator. Containing a dessicant, the drier removes moisture to prevent damage to other components in the system as well as filters out any loose particles that may be present in the system. The drier is an important part of the air conditioning system and should be replaced any time the system is opened for maintenance. Since it can be placed anywhere in the high pressure line, the drier can be hidden or mounted in view.

Condenser
Two conditions are required to condense refrigerant gas into a liquid: high pressure and the removal of heat. After the compressor puts the refrigerant gas under pressure, it enters the condenser where heat is removed and the refrigerant becomes a liquid.

The condenser needs to be mounted where it can receive ample fresh air across it. The recommended location for maximum condenser efficiency is in front of the radiator. However, it can be mounted remotely if there is absolutely no room in front of the radiator. Call the Hot Rod Air Tech Line for remote condenser information.

Safety Switch
The safety switch is one of the most important yet most overlooked portion of the air conditioning system. The function of the safety switch is to monitor high and low side pressure and shut down the system if the pressure exceeds safe or drops below operating limits.

The binary switch simply splices between the compressor clutch and evaporator thermostat and taps into the high pressure line. When pressures exceed safe limits, the switch opens the circuit to the compressor clutch thus disengaging the compressor until pressure return to normal.

The trinary switch operates much the same as the binary in that it shuts down the compressor when pressures rise. However, the trinary also controls an electric fan on the radiator that pulls additional air across the condenser to bring pressures down.