air cooled cars do have ok heat to get some of the chil out of the air...but to say they will defrost your windows and sweat you out on a 20 degree aint gonna happen.
and it's been said that a heater box in the off cabin position can actually make excessive heat under the heads and cause higher engine temps...though i have never temp guaged it...i kinda think it makes sense so lots of guys take em opff and put j tubes on to help keep sthe heads a touch cooler from the heater boxes building up heat.
but tis is an un documented thing.![]()








,it's not always gonna be summer,moisture in the cabin comes from a not completely sealed system:
rumor Schell 

leading into the cabin after removing the hoses(#2 in your case) from the body