Re: [A/S] Heat pumps

[Jack Canavera <jackcanavera@xxxxxxxxx>]

Just as an afterthought Hunter, the heat pump can
actually freeze up if the outside humidity is high
enough.  According to the documentation that I got
from Duo-Therm, the defrost cycle will not begin on my
unit until outside temps drop below 38 degrees. The
cycle is triggered by two factors, one being outside
temperatures, combined with a certain amount of run
time within a heating cycle.  So technically it can be
below 38 but if the cycle run time is short enough,
the defrost cycle will not run.  

This last fall while down in Branson during a 42
degree day in rain, the outside coils froze up
completely.  I had gone out for dinner and when we
came back to the trailer the heat pump was running but
the inside temp was 66 degrees.  Air coming out was
just warm (normally around 90+ degrees).  I went
outside and saw the outside coils were completely
frozen over.  Obviously we had to switch over to
furnace.  Two nights later with no rain, the heat pump
ran fine even though temps dropped below 42.  The
difference being a much lower humidity situation.

So caution should be used if you are depending up the
heat pump if you are in high humidity situations with
lower temperatures.

Jack Canavera
STL. Mo.
'04 Classic S.O. 30' 
WBCCI 5024