Equivalence of one ton of refrigeration (TR):

• One ton of refrigeration (1 TR) is defined as the rate of heat removal required to freeze 1 short ton ($2000\text{ lb}$) of water at $0^\circ\text{C}$ into ice at $0^\circ\text{C}$ in 24 hours. In SI units, $1\text{ TR} = 3.517\text{ kW} = 211\text{ kJ/min} = 50.4\text{ kcal/min}$, practically taken as $3.5\text{ kW}$.
• $2.5\text{ kW}$ is below the thermal equivalent of 1 TR.
• $1.0\text{ kW}$ equals $0.284\text{ TR}$.
• $4.5\text{ kW}$ equals approximately $1.28\text{ TR}$.

Sensitivity of reversed Carnot cycle COP to operating temperatures:

• The theoretical COP of a reversed Carnot refrigeration cycle is given by $\text{COP} = \frac{T_L}{T_H - T_L} = \frac{T_{\text{evap}}}{T_{\text{cond}} - T_{\text{evap}}}$. Differentiating with respect to $T_L$ shows that changes in the lower temperature (evaporator temperature) yield a substantially greater fractional percentage impact on COP than equal changes in the higher condenser temperature.
• While condenser temperature affects COP, evaporator temperature has a proportionally stronger effect.
• The Carnot cycle is independent of the working fluid or refrigerant.
• Specific heat of fluid does not alter theoretical Carnot cycle limits.

Psychrometric conditions for winter air conditioning:

• In winter air conditioning for human comfort and moisture control, the relative humidity is maintained between $30\%$ and $40\%$ (and should not exceed $40\%$) to prevent moisture condensation and frost formation on cold exterior windows and building walls.
• $60\%$ is common in summer air conditioning.
• $75\%$ causes heavy condensation, dampness, and mold growth in winter conditions.
• $90\%$ causes saturation and severe condensation.

Thermal efficiency relationships in convective grain drying psychrometry:

• The sum of heat utilization and performance ratio does not equal an additive increment above unity.
• In grain drying thermodynamics, the Heat Utilization Factor is defined as $\text{HUF} = \frac{T_1 - T_2}{T_1 - T_0}$ and the thermal Coefficient of Performance (or loss fraction) is defined as $\text{COP} = \frac{T_2 - T_0}{T_1 - T_0}$, where $T_1$ is entering hot air temperature, $T_2$ is exhaust air temperature, and $T_0$ is ambient air temperature. Consequently, $\text{HUF} + \text{COP} = \frac{(T_1 - T_2) + (T_2 - T_0)}{T_1 - T_0} = \frac{T_1 - T_0}{T_1 - T_0} = 1$, leading directly to $\text{HUF} = 1 - \text{COP}$.
• HUF and COP represent complementary energy proportions.
• HUF is not the reciprocal of COP.