Aftermarket AC for Your Car: Can You Add Air Conditioning to a Car Without It?

Yes, in most cases you can add air conditioning to a car that didn't come with it. Aftermarket A/C for cars comes two main ways: vehicle-specific kits that bolt into many classic cars and trucks, and universal under-dash units that can be adapted to almost anything with room for the parts. Whether it's practical depends on the car.

A few questions decide it. Is there a kit made for your car? Does the engine have room and power for a compressor? Can the cooling system handle the extra heat? And is the car worth the investment to you?

How does aftermarket A/C work?

An add-on system works the same way factory A/C does. There's no self-contained box that plugs in and makes cold air. A real system needs every one of these parts, connected in a sealed loop:

• Compressor, mounted on the engine with a bracket and driven by a belt
• Condenser, mounted in front of the radiator to shed heat
• Receiver drier, which traps moisture in the refrigerant
• Evaporator, inside the car, where the air gets cold and dry
• Hoses and fittings, routed between all of them
• Controls and wiring, including a safety pressure switch and often an electric fan

Vehicle-specific kits vs. universal under-dash units

Vehicle-specific kits

These are engineered for a particular model and year range, mostly popular classics such as Camaros, Novas and older Ford F-100 pickups. Vintage Air, which makes these kits, says its SureFit systems are available for both original factory-air and non-air vehicles. Its complete kits include the compressor, mounting bracket, condenser with safety switch, refrigerant hose kit and an interior evaporator kit with either converted factory controls or a replacement control panel, and they're designed to need minimal modifications.

The advantage is that someone has already worked out where everything goes. The vents and controls often look close to factory, which matters on a classic.

Universal under-dash units

Universal systems use an evaporator box that hangs under the dash with its own vents and controls, much like the dealer-installed A/C units of the 1960s and '70s. They can be adapted to almost any car or truck, but more of the work falls on the installer. In its Builder Series guide, Vintage Air tells buyers to measure the space for the evaporator, choose the largest unit that fits, and select the proper compressor for the application. It also says every A/C installation should include insulating the entire cab, which makes a real difference in a Miami summer.

Factory parts from an A/C version of the same model

If your model was sold with optional factory A/C, it's sometimes possible to install the factory parts. On older cars that can work well. On newer cars, the A/C is tied into the engine computer and climate control modules, which can make a parts swap more involved than it looks.

What about 12-volt and electric A/C compressors?

Hybrids and electric cars use electric compressors, but those run on the high-voltage battery and are built into the vehicle's own systems. They aren't a bolt-on for a gas car's 12-volt electrical system.

There are 12-volt electric compressor systems, mostly sold for truck sleeper cabs, vans and off-grid campers. They draw a lot of current, so they usually need extra battery capacity and a strong charging system, and they're sized to cool a small space.

Then there are the plug-in "portable car air conditioners" that run off the power outlet. Most of them are fans that blow across water or ice. They cool by evaporating water, which works in dry desert air. In Miami humidity they mostly make the car damper. Only a refrigerant system pulls moisture out of the air, and that's what makes a car feel cool here.

What does adding A/C to a car involve?

A good install is mostly planning and fit. A typical job looks like this:

1. Mount the compressor. The bracket has to line the pulley up with the engine's other belts, or the belt wears and slips.
2. Mount the condenser and fan. It goes in front of the radiator, which now has to shed the condenser's heat too. Many older cars need a better radiator or an electric fan to keep up.
3. Fit the evaporator and drain. The evaporator goes under or behind the dash, and its drain has to exit the car, because in South Florida it removes a lot of water from the air.
4. Route hoses and wiring. Hoses are cut and crimped to length, and the compressor clutch, pressure switch and fan get fused, relay-controlled power.
5. Vacuum, leak test and charge. The system is pulled into a deep vacuum, checked for leaks and charged with the exact amount of refrigerant it calls for.

Hose routing is where a lot of add-on systems develop leaks later, from a fitting that rubs or a hose that sits too close to the exhaust. Custom hoses are something we know well: AA Air Conditioning & Radiators builds its own A/C hoses, driers and compressors in the shop.

Is adding A/C to your car worth it?

It depends on the car and how you use it. These are the things that make a car a good candidate:

• A kit exists for it. A vehicle-specific kit saves a lot of fabrication.
• The engine has room and power. Small, older four-cylinder engines feel the compressor more when it engages.
• The cooling system is healthy. If the car already runs warm in traffic, adding A/C will make it worse, so sort that out first. Our radiator and cooling system page covers the usual causes.
• The charging system can keep up. The compressor clutch and fans add electrical load, and an older alternator may need an upgrade.
• You'll keep the car. On a classic you plan to drive for years, A/C can make it usable through a Miami summer. On an economy car near the end of its life, the money may go further toward a car that already has it.

The total depends on the kit and how much fabrication the car needs. Before you commit, get a written quote that spells out the kit, the labor and any parts the kit doesn't include.

Does your car already have A/C that just stopped working?

Before you shop for an add-on, make sure your car doesn't have factory A/C that has simply quit. Plenty of cars that "don't have A/C" actually have a complete system with a failed compressor, a leak or a bad switch. Fixing a factory system is usually far simpler than adding a new one, and our car A/C repair service covers everything from leak detection to compressors.

Ask an A/C specialist before you buy a kit

AA Air Conditioning & Radiators installs complete A/C systems in vehicles that didn't come with air from the factory, on almost all makes and models. Before you order parts, call and ask whether your vehicle is a good candidate. We've specialized in automotive A/C in Miami Gardens since 1992 and work on A/C systems every day, on everything from Hondas, Toyotas and Chevrolets to Bentleys and Maseratis.

Call (305) 654-4455 with the year, make, model and engine.