Which method of calculation or guidance (e.g., HTRI) is not directly dependent on whether the temperature range is cryogenic or not. This might well influence your choice of materials, but not heat transfer calculations or physical details, such as tube size, pitch, baffle spacing, etc. You will, of course, need accurate thermodynamic properties (rho, Cp, etc.) and transport properties (mu, k, etc.) for the fluids. What fluid are you proposing to use for cooling? Presumably a refrigerant? Even if you had very cold air, you probably don't want to use air-to-air. At low temperatures, it would take a lot of surface area (material expense). The process occurring in a car air conditioning evaporator is efficient. That's air on one side and evaporating refrigerant on the other. The fins are on the air side and provide cheap surface area. The refrigerant is inside tubes with much less surface area, but the heat transfer coefficient for evaporation is much higher than for forced convection, so the combination is cost-efficient.