Choose the calculator that best matches what you are trying to evaluate.
These tools demonstrate how supply-to-return bypass airflow can affect system airflow and operating temperatures in heating or cooling mode. One calculator provides a theoretical demonstration, while the other uses actual jobsite measurements.
Which calculator should I use?
I want to demonstrate how bypass affects system temperatures
Choose the Bypass Temperature Demonstration when you want to evaluate how different bypass percentages could affect entering-equipment and supply temperatures.
This calculator is appropriate when:
- You are planning or reviewing a zoning application.
- You want to compare bypass percentages from 0% through 60%.
- You want to see Pass 1, Pass 2, and theoretical steady-state temperatures.
- You have the system airflow, return-grille temperature, and sensible temperature rise or drop.
- You do not have complete jobsite temperature measurements.
You will need:
- Operating mode: heating or cooling
- Total system airflow
- Return-grille temperature
- Sensible system temperature rise or drop
I have actual jobsite measurements
Choose the Actual Bypass Conditions Calculator when the equipment is operating and you have measured temperatures from the system.
This calculator estimates the effective bypass percentage based on temperature mixing and calculates the estimated bypass and zone airflow.
This calculator is appropriate when:
- You are currently evaluating an operating system.
- You have measured system airflow.
- You can measure the return air before bypass air mixes with it.
- You can measure the mixed air entering the equipment.
- You can measure the supply air near the equipment and upstream of the bypass takeoff.
- You want to estimate the actual effective bypass rather than model a selected percentage.
You will need:
- Operating mode: heating or cooling
- Total measured system airflow
- Return-grille dry-bulb temperature
- Mixed entering-equipment dry-bulb temperature
- Supply dry-bulb temperature
For improved accuracy, you may also enter:
- Bypass dry-bulb temperature at the return connection
- Return-grille wet-bulb temperature in cooling mode
- Mixed entering-equipment wet-bulb temperature in cooling mode
Remarque :
Bypass airflow management is not permitted on Ductless or Crossover Air Handlers.
Bypass airflow management is not permitted on Infinity / Evolution Systems.