In the Shop
As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.
Aug 07, 2009
It takes an hour or less in a modern tractor, combine or hay conditioner cab with a faulty ventilation system to discover that air conditioning is not optional in modern farm equipment. Windows in modern cabs don't open wide enough, or don't open at all. We've all tried to be a hero or tightwad and run without A/C, but quickly decided that saunas should be recreational and not part of daily work. Here are a few comments and suggestions about A/C systems and some of their maladies:
-When an A/C system fails, always check the condenser coil, the radiator-like unit mounted in front of the real radiator. If the condenser is plugged with hay dust, silage chaff or talcum-like field dust, it can prevent a system from cooling properly. If possible, use compressed air to blow out plugged condensers before flushing with water. Using a garden hose or high-pressure washer first can create mud that lodges between condenser fins and restricts airflow.
-If the cab fan/blower stops working, check for a blown fuse on the cab fuse panel. There may also be a fuse related specifically to the A/C system.
-A/C systems are technically not supposed to be worked on by anyone who isn't certified to work on A/C systems. Some farmers tinker with A/C themselves. If you are a tinkerer, be VERY cautious about adding aftermarket or black market refrigerants to A/C systems. There are a few products floating around the market that reportedly use anhydrous ammonia or propane as refrigerants. Anhydrous or propane will act as a refrigerant, but... Imagine being in a cab if an A/C line filled with anhydrous ammonia sprung a leak. Even worse, what if a propane-charged system sprung a leak and an operator lit a cigarette?
-If any noncertified refrigerant is introduced into an A/C system, no certified A/C technician can or will touch it. If they hook up their gauges or test equipment to a "contaminated" system, it causes all sorts of problems with expensive test equipment. Contaminated A/C systems become orphans that no one will work on.
-Got a tractor or pickup that stinks every time the A/C or ventilation system is turned on? There could be a puddle of water or damp spot somewhere in the ductwork with mold, mildew and other evil-smelling stuff growing in it. Auto parts stores sell a variety of aerosol deodorizers that can be sprayed deep into ventilation systems to kill smelly duct-dwellers. Some mechanics have gizmos that connect to ventilation systems to use ozone or ultrasound or special deodorizing compounds to flush and deep-clean ventilation systems. The units cost $200 to $350, so they're probably too pricey for an individual farmer to buy.
Or you can buy a really big, evil-smelling cigar and self-fumigate the next time you plan to spend a couple hours in the cab.