1/8/2008 6 HD320
Stage 2, etc. is only used when needed by the WarmFlo II supply air temperature calculations.
When the warm air sensor is calling for more than the heat pump and Stage 1 100% output, Stage
2, etc. turns on. Stage 1 may not necessarily remain at 100%, but can be modulated downward to
meet the requirements of the warm air sensor.
Also on the next call for heat, the WarmFlo II controller remembers what stages were on and
starts at that point. A clamp-on amp meter at the service input can be used to “visualize” the
Stage 1 modulation and/or Stages 2, 3, and 4 functions.
Note: Power-up reset or return from standby (SB) resets all staging memory and
temperature cycling begins new.
Efficiency*
– the characteristic of a heat pump dual heat system is the heat pump’s ability to
deliver warm air at efficiencies greater than 100%. Gas and oil systems are always less than
100% (60% through 90%), resistance electric (Electro-Mate) is always exactly 100%, but the heat
pump is always at least 100% (-20°F) or greater, up to about 200% for air source.
The user needs to realize it is to his advantage to run the heat pump either continuously or at the
longest possible thermostat call cycles. This is contrary to the basic understanding of most users.
However, realizing again the heat pump is a device that delivers greater than 100%, this system
can only deliver greater than 100% if it’s running, let it run. Because of WarmFlo’s design
concept and its internal “brain” the heat loss curve (diagonal lines, below) allows the compressor
to operate with a minimal amount of electric resistance supplement or temperature boost.
Heat loss curve*
– within the “brain” of the WarmFlo controller is a relationship of supply
temperature (ST) to outdoor temperature (OT) measurement. As it gets colder outside, the higher
needed the supply temperature in order to properly overcome the heat loss within the structure.
This is the diagonal line between 67° outdoor and maximum Btuh (heat loss) at the coldest
outdoor temperature. The slope of this line or the exact warm air position at the coldest
temperature is established by the “efficiency” adjustment knob or dial.
Factory set per table and chip on order sheet.
Temperature (Efficiency Dial)*
– the red center screwdriver adjustment dial has a selection of
A through G. These A through G selections represent a supply temperature point at 0° outdoor.
The closer the user or installer selection is to A, the flatter the heat loss curve or the higher the
operating efficiency. The closer a selected setting is to G, the steeper the heat loss curve or the
lower overall heat pump system efficiency. If dial is turned to “full electric” the WF II will
automatically put all stages of electric to full capacity.
*Does not apply to chip codes such as EMA and EBA.
