Useful answers.
Understand the working.
Calculators and worksheets for the subjects you study and the problems you meet in practice. Work through an example, try your own values, then test the same ideas in exam practice.
Psychrometric calculator
Read a service air state before deciding whether a comfort complaint concerns temperature, moisture or both. Compare the dry-bulb reading with humidity ratio rather than treating relative humidity as a fixed water content.
Open tool →FREE TOOLAir heating and cooling calculator
Translate measured duct airflow into dry sensible heating or cooling duty. Practise identifying which given air density and specific heat belong in an HVAC heat balance.
Open tool →FREE TOOLSuperheat and subcooling calculator
Separate suction-line superheat from liquid-line subcooling. Supply the appropriate refrigerant saturation reference instead of interpreting gauge pressure as temperature.
Open tool →FREE TOOLAir changes calculator
Check the relationship between a measured supply airflow and room volume. Use the nominal interval to explain air changes without promising complete pollutant removal.
Open tool →FREE TOOLFan speed comparison
Explore why a modest speed change can have a larger ideal effect on fan power. Compare the affinity-law estimate with the limitations of an actual duct system.
Open tool →Tools that connect the calculation to the concept
Each tool shows its method, units and assumptions, together with two worked examples. Example values are for learning; replace them with your own measurements or documented inputs. The related study links take you to the matching certification topic on Technical Conquer.
Worksheets run in your browser. We do not send entered measurements or report text to a calculation service. Where export is available, you choose when to save the file locally.
Check the boundary of the answer
A useful result starts with the right inputs and an appropriate method. These tools explain what is calculated and what the method leaves out. User-supplied criteria remain identified as supplied criteria; a calculation does not automatically approve equipment, certify an inspection or establish regulatory compliance.