Evaporator Fin spacing Defrost

[james10]

could someone point me in the right direction, regarding evaporator defrosting, mainly the fin spacing and effect on the defrost.
correct me if im wrong
the smaller the fin spacing, equals the more fins per inch, resulting in a greater surface area, and making frost build up easier due to the smaller gaps between the fins.
as a result the defrost period would have to be increased and the interval more often, the the same size evap with a bigger fin spacing and less fins per inch

[install monkey]

fridge or freezer??

[james10]

Both........

[install monkey]

any fridge should have off cycle defrost by either 3 deg deadband on the stat to defrost an evap or if fanned then again- anything over a 2 deg diff would be sufficient, sometimes a 4x20 min defrosts with just fan will cure it, for a freezer at -18 then again 4 defrosts for upto 40 mins with electric defrosts with a termination stat setpoint of 25deg and a 2 min fan delay or 2 min dripping time

[james10]

That's true, but what considerations should be made with different fin spacing with regards to defrosting

[install monkey]

you havent given us much details into the application, do you want a manual???:D

[james10]

This is just a generalisation, regrading fun spacing and defrost, I'm good for manuals ;)

[install monkey]

http://uk.grundfos.com/service-support/encyclopedia-search/fin-spacing.html

[install monkey]

http://books.google.co.uk/books?id=n5-9_WnXhWMC&pg=PA27&lpg=PA27&dq=evaporator+fin+spacing&source=bl&ots=ovJnaSRVxZ&sig=9Z4-Iyh4KWO69xmeQQcwZnikODA&hl=en&sa=X&ei=SB01UZ_JLumX0QX0sYCIDg&ved=0CFAQ6AEwAw#v=onepage&q=evaporator%20fin%20spacing&f=false

[james10]

gotta share the love :)

[Iceman717]

Tighter fin spacing is going to make defrost more frequent because you'll obstruct airflow faster. Depending on the defrost method, defrost duration could be shorter.

[MikeHolm]

My local mentor designs his coils with 10-12fpi, more packed than that wastes defrost energy but I can see why the japanese pack them in, way less manufacturing/shipping costs