Proper calculation of the usable area of the greenhouse
The choice of a greenhouse is a responsible and important step, on which the effectiveness of the invested funds depends directly. To make the right choice, you must carefully weigh all the positive and negative aspects of all the offered options.
The shape of the greenhouse is one of those "little things" on which the efficiency of the greenhouse as a whole depends very much. Nowadays, the most common shapes are semicircular, oval and Gothic greenhouses.
Semicircular greenhouses are simple in shape and manufacture, but they also have significant drawbacks: the difficulty of using the site along the side and the insufficient volume of the dome space for such an area.
Semicircular and Gothic greenhouses do not have these disadvantages. Let's consider this with a specific example: let's compare a semicircular greenhouse with a width of 10 meters, an oval and a Gothic one with a width of 9.6 m. Let us agree that the working height in the greenhouse is 2.5 m.
As a result of simple constructions, we get: for a semicircular greenhouse, the width at a height of 2.5 m is 8 m, and for an oval and Gothic one it is 9.2 m, which is 15% more with a smaller width at the base. Here I would like to emphasize that in semicircular greenhouses, a fifth of the area is not suitable for full operation.
The volume of the dome space in greenhouses of the Gothic and oval shape is approximately 25% larger than that of the semicircular one. It allows you to more effectively save the microclimate in the greenhouse, and helps prevent overheating (hot air rises). Also, when using overhead ventilation, the dome space serves as a buffer between the outside condition- "street" and the plant growth zone and protects them from stress when too cold / hot air comes from outside. And, as you know, a more comfortable and stable microclimate leads to an increase in plant productivity.
As we have seen, from an agronomic point of view, greenhouses of gothic and oval shapes are much more efficient than semicircular ones. Why are semicircular greenhouses still popular enough? The answer is simple - the cost per square meter in them is less than for oval and Gothic ones. But there is one catch here: the cost per square meter is GENERAL, not USEFUL space. As we mentioned earlier, in semicircular greenhouses, the usable area is much less than the total, and for a correct comparison with oval and Gothic greenhouses, the cost per square meter of a semicircular greenhouse should be multiplied by 1.2.