# Online Emissions Calculator for Engines, Turbines, Boilers and Heaters

Photo by Alex Simpson on Unsplash

## Why do we calculate air pollutant emission rates?

The calculation and quantification of air pollution for the preparation of air emissions inventories are important tools in air quality management. In accordance with the United States Environmental Protection Agency Compilation of Air Pollutant Factors (US EPA AP-42) estimating emissions are important for developing pollution control strategies as well as being a key part of regulatory and industrial processes, especially in terms of permitting of facilities that have the potential to generate significant pollutant emissions. Emission inventories for combustion equipment normally refers to engines, gas turbines, boilers and heaters (sometimes referred to as furnaces).

We also need to calculate air pollutant emission rates for equipment in advance of its installation or where emissions monitoring (stack testing) is not available. WKC’s online emissions calculator can be used to estimate these air pollution emission rates.

## How do we calculate air pollutant emissions from engines, turbines, boilers and heaters?

Where emissions testing data isn’t available, comprehensive, or reliable, the most accepted means of estimating air emissions is the use of internationally recognised ‘emission factors’. Emission factors are usually specific to fuel type used, equipment type and allow the calculation of emission rates for a wide range of atmospheric pollutants.

US EPA AP-42  provides a comprehensive but often complex method of estimating air emissions. A relatively simplistic, but conservative means of rapidly estimating emissions from combustion equipment is the use of Exploration and Production Forum factors, which whilst pre-dating US EPA AP-42, provide a rapid means of estimating air emission rates.

The simplified formula for the estimation of air emission rates from combustion equipment using emission factors is as follows:

E = A × EF

Where:

E = Emissions (tonnes a year of pollutant emissions)
A = Activity (in this case the quantity of fuel used per year)
EF = Emission Factor (tonnes of air pollution emitted per tonne of fuel used)

This online emissions calculator provides a simple method to estimated air pollutant emission rates based on annual fuel consumption.