## 2 Construction Aspects for Energy Performance Improvement
### Greenhouse Construction
#### 2.2.1 Greenhouse Shapes and Their Impacts
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Shape of the Greenhouse** & **Advantages** & **Disadvantages** & **Recommended Climate** \\ \hline Flat Greenhouse [7; 65] & - & Ease of construction & - & Poor drainage \\  & - & Reduced cost & - & Snow accumulation \\  & - & Good wind resistance & - & Limited height in the \\ Arch Greenhouses & - & Even distribution of & center \\ (Quonset) [74; 76; 77] & & light & - & Difficulty installing \\  & - & Excellent weather & - & Higher cost \\ Geodesic greenhouse [78] & & resistance & - & Construction complexity \\  & - & Pleasant aesthetics & & \\ Chapel Greenhouse [7; 71] & - & Additional vertical space & - & Higher construction cost \\  & - & Good ventilation & - & Structural complexity \\  & - & Easy to build and & - & Limited internal height \\ Tunnel Greenhouse [79; 80; 81] & & expand & - & Vulnerable to damage \\  & - & Cost-efficient & & from strong wind \\  & - & Optimized ventilation & - & More complex \\ Greenhouse in Saw or & - & Optimized ventilation & - & construction \\  & - & Good access to natural & - & Vulnerable to wind \\  & - & light & damage & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Advantages, Disadvantages and Recommended Climate of Greenhouse Forms. [PERSON] et al. [85] applied dynamic simulations to conclude that certain orientations and structures, such as Quonset, improve energy efficiency in Morocco. The study concluded that in Agadir, Morocco, the east-west orientation can reduce air-conditioning costs by 9.28%, while the Quonset-shaped structure provides an even greater saving of 14.44% in annual HVAC costs compared to regular airhouses. In addition, the use of Polycarbonate Hollow Sheets (PHS) as the roofing material reduces the heating demand by 29.2%, and the use of air as a filler gas in Polyethylene (PE) roofing is economically advantageous. [PERSON] et al. [86] used genetic algorithms to find that Quonset greenhouses in Iran capture solar energy better. The research focuses on optimizing greenhouses in northern Iran to maximize solar energy use by analyzing three common types of greenhouses (Span-Regular, Modified Arc, and Quonset) and three area sizes for each type. A mathematical model calculates the radiation loss and the available solar radiation, aiming at multi-objective optimization for higher solar capture in winter and lower in summer. For regular-span greenhouses, the ideal wall height is 3.8 m with a roof angle of 16\({}^{\circ}\). In modified arc greenhouses, the ellipse ratio varies, 0.8 for small and large sizes, and 0.25 for medium. For Quonset, the ratio is 0.6 for medium and large, and 0.8 for small. The Quonset type is the most efficient for annual solar use. [PERSON] et al. [81] conducted an evaluation using a prototype photovoltaic greenhouse. In this study, we analyze the evolution of PV installation in greenhouses and the effects of shading on crops under these structures. Specifically, it examines tunnel greenhouses, whose curved shape challenges PV installation. Using transparent flexible PV panels of 1116 m x 0.165 m, with an efficiency of 18%, the study evaluates the shading variation within a prototype greenhouse. It was observed that the shading, caused by the checkerboard arrangement of the panels, does not exceed 40% throughout the year, with significant seasonal changes. In the study of [PERSON] et al. [69] evaluated the influence of the shape and orientation of regular-span greenhouses on their thermal efficiency, comparing five common configurations (even-span, uneven-span, vinery, modified arch and quonset) in relation to solar radiation absorption at different latitudes and orientations (east-west and north-south). Through mathematical modeling and experimental validation using data from a typical summer day in Ludhiana, India, the results indicated that the east-to-west uneven-span shaped greenhouse maximizes solar radiation reception during winter while minimizing it in summer, which is preferential for year-round crop production at various latitudes.