FUNDAMENTALLY
COOL Getting a grip on air conditioning WORDS & PHOTOS: Todd Ryden
The key to cooling the interior is by efficiently changing the state of the refrigerant as it cycles through the system.
Y
ears ago, rods were basic builds with no accessories, bells, or whistles. They were meant to either be quick or look cool, and sometimes both. As time and technology have progressed, many builds have become more refined with creature comforts for a more comfortable drive. One such accessory that has become the norm is air conditioning — and with good reason. Southern states that drip with humidity through the summer make it unbearable to cruise, and the Midwest reaps some pretty serious heat during prime cruise months, as well. Remember, an A/C system not only cools the air, but it removes the moisture to keep your cabin cool and dry. It’s no surprise Vintage Air, the original street rod A/C company, was started in one of the hottest and most humid cities in the country — San Antonio, Texas. If you could develop an A/C system that keeps a street rod cool in San Antonio, then 38
STREET ROD LIFE Vol. 3, No. 1
you’re pretty well set for the rest of the country! Vintage Air knows what it takes to make a car stay cool on the inside, but for many of us, understanding what exactly is going on inside those hoses and tubes is a mystery. Automotive air conditioning may seem tricky to understand at first, so let’s take a look inside to get a better grip on keeping cool. The best thing to compare the actions and flow of refrigerant is to think back to middle school and the hydrologic cycle. As it’s heated, water evaporates from a liquid to a gas. Then as it cools, it condenses back into liquid form again. And if you were awake for any physics courses, recall that heat always transfers from a hot object to a cool object. Never the other way around. The A/C system does the same basic thing with refrigerant, as you can see in the diagram. Refrigerant enters the compressor as a cool, low-pressure gas and exits as a hotter, high-pressure