Our 12 foot by 16 foot greenhouse is a lean-to on the south west side of the house. The temperature range is controlled by a thermostat and an automatic roof vent. The humidity is checked and augmented as necessary.
The greenhouse floor is four feet below ground level. This gives us a ceiling height of about 12 1/2 feet, and helps stabilize the temperature and humidity. Summer or winter, 80 degrees in the greenhouse will cause the roof vent to open. During the winter the night temperature is set to 55 degrees and during the day 70 degrees. The humidity is checked every hour (automatically). If necessary, the misters will go off for 10 seconds.
Watering is also automatically controlled. All the plants are watered by sprinklers three times a week. On Saturday, about a half hour after the watering, we fertilize. Bloom booster (high phosphorus) is used the first week of the month and Growth (high nitrogen) the rest of the time.