Reefer temps

Yes

 

The evaporator gets ice built up on it, gets let's air flow through the fins, and I believe the temp of the ice is warmer than the temp of bare metal. It cools with less effiency, or hardly at all if its plugged with ice. The more humidity in the atmosphere, the quicker ice builds up on the evaporator. The defrost times can be changed in the settings.

 

Gets less airflow

 

Probably loaded the product hot,

99% of the time I only run zero, unless I’m doing something brokered where it specifies -10 on the BOL, not that these places keep their freezers that cold to begin with (unless it’s ice cream)

 

This driver needs to get him handheld thermometer and note product temperature when loaded, we did this in the early 2000's. While I worked for foodservice company.

 

Yes always set it at the temperature the shipper has requested you to do, therefore you won't be held accountable if something happens to the product, anything below 32 F is freezing so yes - 10 F = about - 22 C. Which is very freezing. Anything like ice cream and frozen veg that is the standard temp they need to be stored at.

 

I try to always pre cool. When going to next pickup empty for chilled loads. Then if product is above freezing like fresh meat, I will open door vent when driving if possible to vent some air out. Or Crack doors once every few hours until frozen temp is reached. If load is not sealed at pick up.