- Fans Perform Separate Functions: We recommend two distinct fans in a greenhouse. An air-circulating fan does what the name implies — gently circulating the air to prevent stagnant spots or stale air. It keeps air moving throughout the structure. This fan runs constantly, 24 hours a day, to keep air moving at all times. A heat-saver fan mounted up high pulls hot air from the roof of the greenhouse and circulates it downward to provide warmth in the areas where the plants are.
- Humidity Dial is Essential: A humidity dial is an essential accessory. It keeps a constant reading on how much moisture is in the air. Many plants such as orchids and other tropical plants thrive best at specific levels of humidity.
- 4-Way Analyzer Tests Soil: A 4-way analyzer uses a probe that is inserted into a plant’s soil. The readout on the meter indicates levels of moisture, light, pH content and soil nutrients. This device will help you know if a particular plant needs more or less light, water or fertilizer.
- Light Meter: A light-intensity meter uses a probe placed in proximity to a plant to indicate the level of light being received. The sensor uses a photovoltaic cell, so no batteries are necessary.
- Thermostat Maintains Climate: An specialized electric heater that is moisture resistant and has a very sensitive and accurate thermostat for maintaining a constant and even temperature inside the greenhouse. It can be mounted to the wall.
- Starter Trays: Seed-starter trays, used in conjunction with a heated seed-mat and suspended light, are used to germinate seedlings in the spring. The clear domes on top of the trays help contain moisture to prevent the seeds or new plants from drying out.
- Control Monitors Heat on Seeds: A thermostatic control for the heat mat ensures that seeds and seedlings are maintained at the ideal temperature for germination and growth.
- Misting System: An automatic misting system installed throughout the greenhouse simplifies watering, and (when used on a timer) provides water when you’re away.
- Electronic Monitor: An electronic monitoring station has a radio-controlled clock precisely set to a U.S. atomic clock. The readout on the meter indicates temperature and humidity readings in the greenhouse where the sensor is placed. The meter operates remotely from the sensor, and has a range of up to 300′. In this way, you can check the conditions in your greenhouse from inside your home.
SOURCE:http://www.diynetwork.com/how-to/outdoors/structures/features-and-devices-for-the-greenhouse