# Assessing Energy Efficiency in Desktop-Size FFF 3D Printers
## 3 Results and Discussion
When starting from ambient temperature, power demand is highest at the beginning of the phase due to the significant temperature differential, with values declining as the target temperature is approached. Machines with glass worktables displayed the smallest power variations during heating. Table heating time, not exceeding 10 min, depends on control program settings for PLA (30 C to 60 C), as well as heating element type, size, and power source efficiency. The third phase of stable energy consumption is extruder heating, which requires significantly less power than worktable heating. Unlike worktable heating, no substantial power variation occurs between the start and end of this phase, and extruder heating generally completes within 4 min. During testing, maximum instantaneous energy consumption was also recorded. For two machines, power consumption briefly exceeded nominal power supply values. In the Prusa MK3+, this was a short-lived event, while the CR10s Pro drew above nominal power for an extended period during worktable heating. Notably, both machines have functioned reliably under research use, with no power supply overheating or malfunctioning observed. DC power supplies should ideally operate within their rated power. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Device**} & \multirow{2}{*}{**Idle [W]**} & \multirow{2}{*}{**Process**} & \multirow{2}{*}{**Total Energy**} & \multirow{2}{*}{**Energy Used to Sustain**} & \multicolumn{2}{c}{**Percentage of Total**} \\  & & **Time [min]** & & & **Consumption [kw]** & **Electronic [kw]** & **Electricity Consumption [\%]** \\ \hline Anet A8M & 8.55 & 31 & 0.05625 & 0.004418 & 7.85\% \\ Creality CR10s PRO & 16.7 & 37.5 & 0.11675 & 0.010438 & 8.94\% \\ Creality Ender 3 V1 & 9.025 & 46.75 & 0.09375 & 0.007032 & 7.50\% \\ Creality Ender 3 V2 & 6.4 & 47 & 0.091 & 0.005013 & 5.51\% \\ Creality Ender 3 V3 & 7.7 & 45.5 & 0.09425 & 0.005839 & 6.20\% \\ FlashForge Creator Pro & 12.675 & 34.5 & 0.0595 & 0.007288 & 12.25\% \\ Prusa 13 MK3 & 17.175 & 41.75 & 0.08175 & 0.011951 & 14.62\% \\ Raise3D Pro2 & 38.475 & 43.25 & 0.18975 & 0.027734 & 14.62\% \\ Tevo Delta Little Monster & 43.625 & 29.25 & 0.1115 & 0.021267 & 19.07\% \\ VSSHAPER PRO & 74.75 & 41 & 0.14225 & 0.051079 & 35.91\% \\ Zortrax M200+ & 46.75 & 49.5 & 0.06875 & 0.038569 & 56.10\% \\ Zortrax M200+ & & & & & \\ without filtration & 40.25 & 49.25 & 0.06025 & 0.033039 & 54.84\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Share of energy required to sustain electronic systems in relation to the total energy used to manufacture the product. As production time increases, the relative impact of initial heating phases on total energy consumption diminishes. Using the test product's geometry as a reference, energy consumption was measured per unit of machine working volume and per unit of product volume (see Table 4 and Figure 3). Observations indicate that the delta-type machine had the lowest energy consumption per working volume unit, while the machine with the highest baseline electronic energy consumption also had the highest total consumption. However, the machine with the smallest working chamber volume followed closely behind. When calculating energy consumption per unit volume of the product, this ranking changes, with the smallest working volume machine performing just below the top in energy efficiency. The statistical analysis was conducted using Minitab (v. 17) software to evaluate the relationship between energy consumption and machine parameters. A linear regression model was applied to determine the correlation between machine characteristics, such as printing volume, drive type, and chamber type, and energy consumption metrics, including kWh/g and kWh/cm3. The significance of these relationships was assessed using \(p\)-values, with a threshold of 0.05. For instance, the relationship between machine volume and energy consumption was found to be statistically significant (\(p\) = 0.005), indicating a measurable impact of machine size on energy efficiency.