View Full Version : Evaporator fan flow direction

28-06-2011, 12:04 AM
Came across an evaporator today that is the first i seen as far as the way the air flow is across the coil and wanted to make sure it was right. It is a BOHN WK075AC The question is does it matter which way the air is going across the coil ? on this evaporator the air is being pulled up thru the one fan on the bottom and blowing air from the inside out.( this makes cleaning the coil very difficult cause you can not get to the coil on the inside unless you remove the fan and blade and then you only have a 12 inch hole to work with) I would think that the air should be pulled from the outside in thru the coil and discharge thru the fan on the bottom. so i was just wondering if any of you new as to why it would be like this. Is it supposed to be like this ? what effect will it have on the system etc.....

28-06-2011, 03:06 AM
Forced draught or induced draught, the evap manufacturer would have designed the refrigerant flow through coil to be counter flow to air flow for max performance. Suggest hinging the fan deck for better access.

28-06-2011, 10:47 AM
Hi jak
Another note on the airflow is I think it is more efficient to blow air through the coil than pull (induce) it through. this is because the air is slightly pressureised which will increase the temperature of the air slightly giving a greater temperature difference between refrigerant and air (on cooling mode). If it were heating like a heat pump it would be the opposite.

04-07-2011, 04:51 PM
Is this evaporator mounted on the ceiling in the center of the room with a short height say 8"? If so, these are designed to be space savers so more product can be stored on shelving against the walls of the cooler or freezer. To clean, yes remove the fan guards and fan blades and start cleaning.

Fridgy Dave
14-07-2011, 08:55 PM
Tesla is right about blowing through the coil because you are taking the fan heat out of the space without cycling it around.