When setting up a greenhouse, take into consideration your needs, the desired growing space, planting methods and your budget. The goal is to create the right environment for maximum growth. When growing plants in a building, it's essential to regulate the temperature, carbon dioxide levels and water at all times.
Locate the greenhouse where it will be exposed to the most sunlight. All-day light is ideal, but plants will do just fine with morning sunlight. The best spot is in the south or southeast side of shade trees or a building.
Install a heating device to regulate the temperature and keep the chill at bay on winter nights. A 220-volt circuit electric heater works well, as does a small gas heater installed in a masonry wall. Avoid kerosene heaters because the emitted gases can affect growth of some plants.
Get the air continuously circulating in the winter for maximum growth. Air movement will ensure that the temperature stays the same in all parts of the greenhouse. Otherwise, warm air will rise to the ceiling, and the cooler air will stay around the plants. According to West Virginia University Extension Service, use small fans with cubic-foot-per-minute capacity that matches one-fourth of the air volume inside the building. Greenhouses that are less than 60 feet long will do well with two fans, placed opposite from each other in diagonal corners facing out. This will create an oval air movement pattern.
Ventilate the greenhouse in the summer to remove moisture, control the temperature and get more carbon dioxide in the building. Place exhaust fans at each end of the building or use a natural ventilation system. This involves a roof with vents or louvers that allow warm air to exit and cool air to come in.
Cool the greenhouse during the summer if ventilation isn't enough. Use an evaporative cooler with a capacity of 1 to 1.5 times the structure's volume. The unit cools the air and increases humidity, and warm air exits through roof vents.
Put a watering system in if you're unavailable to water the plants during the day. Automatic watering systems, sometimes purchased in kits, can be controlled with sensors or time clocks to make sure the different types of plants get the water they need for maximum growth.
Separate the greenhouse into sections. Set irrigation systems up so that each section is handled independently. Drip irrigation system sensors will determine when the soil surface has a sub-optimum moisture level. Water will then be applied drop by drop.