good..
top the column - > top of the reflux column.
it could go out into the atmosphere. wouldn't this defeat the purpose of the methanol recovery?
thought so..
now that you understand the roll of the reflux column..

at the top of the column there is a 'U' shaped piece. this could be made from two 90 degree elbows...
the net effect is a downward turn towards the condenser( air cooled or water cooled)
the goal to the re condense the methanol vapor back into to liquid. if the reflux column is working properly then we'll get high purity methanol only..no water in the methanol.
I think we've come back around your original question..which is more efficient? really either will work just fine..since you a source of car radiators( hopefully the fans too) I would suggest that route. I also use an air cooled condenser. it works fine.
we'll get back to the PID info after I post my diagram on another thread.
-dkenny
'84 bluebird school bus, DD8.2L turbo( 4/2011, the bus tranny has died..

8.23.11 bus driven to scrap yard

)
2006 Jeep Liberty CRD

- the wife's
99 dodge 2500 5.9l 24v..-mine
everything run B100 when its warm enough