*3.3. Environmental Considerations*

The SHES reduces the dependency on fossil fuel lowering the environmental footprint of RTCs since the transportation logistics are minimized and the consumption of vehicle-fuel transporting fuel to the base campsite is also reduced. The generators, rather than being fueled by diesel (as currently done in Canadian Armed Forces), could be powered by LPG (Liquefied Petroleum Gas) to produce lower amounts of harmful greenhouse gases. However, the risks due to the transportation of more hazardous materials must be considered.

Table 8 reports significant annual CO2 emissions savings compared to the baseline when all the SHES technologies are implemented for accommodating 150-person in a temperate climate (Brandon, MB). CO2 reductions up to 39% are also achievable with the deployment of the system in extreme hot and cold climates (Table 8). The CO2 emissions were calculated based on the annual diesel consumption to produce power by the generator and thermal energy by the boiler, assuming an emissions factor of 2.4 kg-CO2e produced as a result of burning each liter of consumed diesel. It was also assumed that diesel has a carbon content of 88%.


**Table 8.** CO2annual emissions for different scenarios of a 150-person RTC operating in different climates.

The SHES is designed to be easily integrated with other water and waste infrastructure systems, e.g., it could be combined with deployable water purification systems (e.g., Aspen Water) powering them as AC loads or using directly the solar energy of the photovoltaic panels or with deployable waste-to-energy systems (e.g., Energos Technology and Eco Waste Solution), which convert wastes into thermal energy (e.g., DWECX-TEEPS) that can be used locally. Moreover, the waste heat coming from the waste converter exhaust of the waste-to-energy system could be captured and used to produce space heating.

## *3.4. Enhanced RTC Construction*

The existing standard RTCs are constructed with materials (canvas) that suffer from poor thermal performance leading to higher heating and cooling energy consumptions to maintain the thermal comfort of deployed soldiers. Consequently, the low thermal resistance of the existing shelter systems requires the design of bigger HVAC systems. Standard tents are constructed of such materials mainly due to their lightweight and waterproofing abilities, allowing for their easier transportation, installation, and long service life. However, recent developments in innovative materials made it possible to provide such properties combined with improved thermal performance to achieve higher energy savings [23,24]. Notably, 13 mm aerogel-enhanced blankets were proposed to be integrated into the existing construction to make significantly improved RSI-values of 0.625 m2K/<sup>W</sup> compared to 0.175 m2K/<sup>W</sup> as demonstrated in Table 2 earlier [23]. Such blankets have an extremely low thermal conductivity of 0.015 W/m. K, while having low toxicity, low density of 200 kg/m3, excellent fire rating, and high recyclability. Figure 12 shows a recently patented aerogel blanket obtained at Ryerson University using an ambient pressure drying (APD) process.

Energy simulations were conducted to assess the energy performance of the camp integrating SHES and high-performance tents incorporating the aerogel blanket produced into the interior of the existing canvas. Table 9 reports the results for different climate zones. The results show that enhancing the thermal resistance of the RTCs has significant impacts on increasing the camp energy efficiency for all climate zones. When compared to Scenario 6 results (SHES), it becomes clear that aerogel-enhanced blankets have their highest energy reduction impacts in extreme climates as Churchill, while still offering significant reductions in the other climate zones.

**Figure 12.** New aerogel-enhanced blanket obtained by the authors and used to enhance the tent material fabric providing higher thermal resistance.


**Table 9.** Energy consumption and CO2 annual emissions results for different scenarios (SHES and aerogel blanket are used) of a 150-person RTC operating in different climates.
