re-circulation over one end?

[ocpike102]

Can someone please explain to me how a heat exchanger with Over one end recirculation works?

 

[Jason5000]

If you're talking about in a fin fan for winterization have a look here:

http://www.eng-tips.com/viewthread.cfm?qid=215669&page=7

 

[maddocks]

you monitor plenum temperature on the cold air side and then you construct ducting and louvers such that the warm air existing the top of the cooler is re-directed back into the inlet of the unit to prevent over-chilling and freezing of the bundle in cold ambient conditions. Over-the end is typical but in multi-bundle applications, it's more advisable to do over the side for better control. You have to be careful with duct size so you don't pinch the fan too much. As well, you need to consider the fan HP draw with the cold air - it will jump up dramatically.