Re: On coil / off coil temperature. Originally Posted by The Viking First you would have to determine what type of kit you are looking at. In your example above, for the indoor coil, the on coil temp would be 24 degrees for a recirculating unit and 45 degrees for a 100% fresh air unit...e: On coil / off coil temperature. Originally Posted by The Viking First you would have to determine what type of kit you are looking at. In your example above, for the indoor coil, the on coil temp would be 24 degrees for a recirculating unit and 45 degrees for a 100% fresh air unit...