Introduction
In maltings operations, controlling process air during steeping, germination, and kiln drying is essential for consistent product quality and efficient energy use. Psychrometric charts are widely used to understand moist air behaviour, but their engineering value goes further than visual interpretation. By defining any two independent properties such as dry-bulb temperature, wet-bulb temperature, relative humidity, or specific enthalpy all other air properties can be derived.
When applied between a defined inlet (ambient or recirculated air) and outlet (process or exhaust air) condition, the change in enthalpy can be directly calculated. This enthalpy difference is a critical engineering parameter, enabling optimal sizing of heaters, and the effective integration of heat recovery units.
Within the maltings division at Don Valley Engineering, this forms the basis for more consistent and energy-efficient system design. Traditionally, psychrometric charts have been read manually, which can introduce variation in engineering judgement and reduce repeatability across projects and operators.
Limitations of Manual Chart Use
Human interpretation can lead to small inconsistencies:
- Subjective interpolation between saturation curves and constant enthalpy lines
- Inconsistency between engineers and project phases
- Differences in scale reading between engineers
While often subtle, these differences can have a knock on affect which can drastically change energy calculations and design optimisation.
Computerised Psychrometric Plotting Approach
The computerised system applies standard thermodynamic relationships directly to maltings air systems. Instead of manual chart reading:
- Psychrometric properties computed numerically from two known conditions
- Automatic chart generation
- Consistent outputs for all users
- No manual interpolation needed
- Repeatable energy and airflow calculations for kiln and germination systems
- Standardised engineering basis for all maltings projects
This ensures psychrometric analysis reflects engineered data rather than individual interpretation.
As the maltings industry becomes more energy-integrated and data-driven, consistency in process air modelling is increasingly important. At Don Valley Engineering, computerised psychrometric chart generation improves design accuracy, supports effective heat recovery integration, and enhances clarity across engineering teams. It also enables us to develop optimised solutions that minimise energy use, reduce carbon footprint, and avoid overdesign or wasted energy, all while maintaining full thermodynamic integrity.
If you’re looking at a malting project and require advice then talk to our experts sales@donvalleyeng.com