Of course the answer to this question is yes, you do need ventilation for your greenhouse. But what if your greenhouse is in a location with no electricity? There are several options which will alleviate this problem. The simplest thing to add is roof vents or side vents. A lot of the greenhouse kits will come with these either as standard equipment or as an option. If you are building your own greenhouse, you would just frame them out using the same material as your greenhouse and cover them with the same material as well. To simplify matters even more, I recommend using solar powered openers with these. This is an arm that is operated by a wax cylinder. It is a pretty basic piece of equipment. It functions on the principles of contraction and expansion. When it is warm the wax will expand and cause the arm to open. When it is cool the wax will contract and cause the arm to pull shut. There is no exact temperature setting on these, but there is a thumbscrew at the end which can be used to adjust the opening and closing temperatures. They are typically able to open between 65 and 75 degrees F, depending on the manufacturer. They will definitely simplify your life during the spring and fall months. No more getting up in the morning and opening them before you head out to work. Then, if you get home and forget to close them at night, the results could be devastating.
If you are building your own greenhouse, or need ventilation in an existing greenhouse, our solar powered shutters are perfect. They will supply natural ventilation for your greenhouse. They come in 6 sizes and require no electricity. The 4 smaller sizes may be fitted into a polyfilm greenhouse without any further framing. Or, they may be installed in a framed out opening the same as the 2 larger sizes. These shutters are perfect for just about any outbuilding, not just for greenhouses.
A final suggestion for natural ventilation is roll up side curtains. These are typically found in polyfilm greenhouses only, and come with a manual hand crank.
In conclusion, not having electricity in an area where you want to put your greenhouse should not be a deterrent. Use any of these systems, or any combination of these systems to help ventilate your greenhouse. Also, if you don’t like any of these suggestions, another way to go with this is to use solar panels to supply electricity to your motorized ventilation systems.