Humidity control based on an estimation using heating plant cycle, of inside window surface temperature

摘要

A humidity control system for an enclosure requiring heat from a furnace and having one or more windows, includes sensors for the enclosure temperature and humidity, and a means for measuring the percentage of time which the furnace is operating (load factor). The system estimates the interior window temperature based on these parameters and controls humidity added to the enclosure air to prevent the enclosure air dew point temperature from rising above the estimated window temperature. This prevents condensation on the window surfaces. The estimation can be adjusted to compensate for different insulation characteristics of the window. In a preferred embodiment, the enclosure air temperature and humidity are derived from sensors conveniently located in the return air duct.