We have a greenhouse with an evaporative cooler that is switched on
and off by a White-Rodgers 1609-101 (or 1609-105) temperature
controller. This is a hydraulic action controller (with a probe or
"bulb")that will close contacts on rise in temperature and open them
on fall. The controller handles a full load of 7 amps at 120 volts.
Our temperature controll needs are in the 60 to 90 F range, though the
controller extends well beyond this. Our problem is that the high
humidity in the greenhouse causes these mechanically-based controllers
to fail within a few years. We are wondering if any growers can
suggest an alternative controller with similar characteristics that
would be more suitable for a greenhouse environment? White-Rodgers
does not make any controllers of different design than the
1609-series.