Let me Vent!

No I’m not going to whine and complain about anything or “tell anybody off”, I’m talking about letting a refrigerator vent.  Although we are talking about a hot head.

Many times we get calls from customers with a complaint of the refrigerator working intermittently.  When they leave to go camping the fridge is working fine and kept doing so for the first day, but then the fridge starts warming up and eventually gets to a point where the food spoils over the following day.  The customer turns it off and uses a cooler for a few days and then decides to try the fridge again.  Overnight it drops into the correct temp range, they put their food back in and the process repeats two days later.  Very Frustrating.  Do they have a bad cooling unit?  Maybe the power board is faulty or a sticky relay.  Nope!  It’s the ventilation.

An ammonia refrigerator requires a lot of air flow to keep the top of the cooling unit cooler than the bottom of the cooling unit.  When the temperatures outside rise, fans don’t run as well, or you have a blockage in the chimney you will see the exact behavior described above,  Running the refrigerator on propane will make it even worse due to the exhaust of the flue heating up the chimney air as well.  So how to prevent it… or at least save a camping trip temporarily?

You need additional airflow.  Put a box fan on the ground outside the access cover blowing up into the chimney.  Take off those access covers and run it on electricity if possible.  If it’s already at the “too hot at the top” stage, turn it off for 2 hours while you set up your fans and then turn it back on.  This will allow the ammonia to return to a more appropriate temperature