Keeping your cool

When the weather gets hot we rely on the Air Conditioning in our units with cabs on them to help keep us cool.  These systems work great, but there is some maintenance to them as well.  When it is hot, you blow out your radiator to keep your engine cool, but sitting on top of that cab is a different kind of radiator that needs to be serviced to keep you cool.

It helps to understand how the AC system works to know exactly how service affects its performance.  No matter where the AC system located,  in a house, a car, or in a Toro mower, the basics of the system are the same.  There are three main components to the system.

Compressor – Spun by the engine and charges the system

Evaporator coil – This is the coil that gets cold and we force air over it to cool the air in the cab.  It is located above the headliner within the cab.

Condenser coil – This is the coil that gets hot and we force outside air over it to cool it.  Just like a radiator for the engine.  It is located on top of the cab and has a fan mounted on it.

You may have heard about high and low limit switches on an AC system.  The low switch turns the system off if the pressure gets too low.  (If there is a leak) The high pressure switch shuts the system off if the pressure gets too high.  This happens when can’t cool down the condenser coil because we cannot get enough air across the coil. (Typically because it is plugged)

AC Compressor

The top things I see affecting AC performance on our units are a compressor belt not being tight enough, or a plugged condenser coil tripping the high pressure switch. A plugged coil can put stress on the entire system causing other failures as well.  Pump seals, hose fittings, and coil leaks can all result from a plugged condenser coil.

Pull out screen under coil

There is a screen located beneath the coil to help keep the coil from plugging up, but it needs to be serviced regularly.  Just like the engine radiator, how often it needs to be cleaned depends on the conditions.  If you have to blow out your radiator more often, your AC condenser will also need to be cleaned.  Just cleaning the screen may not be enough at times.  You may have to pull the fan and shroud to gain access to the coil.  With this removed, you can properly clean the coil with compressed air and or water.

Keeping the condenser coil clean will help keep stress off the system and keep you cool when you need it most.