Since its creation in 1985, ICF has developed and supported U.S. Environmental Protection Agency's (EPA) Vintaging Model. This model tracks and analyzes the stock of equipment containing ozone-depleting substances (ODS) and ODS substitutes over time.
The Vintaging Model provides a framework for evaluating the implications of alternative strategies for reducing ODS use. It estimates the annual chemical emissions from six different industrial sectors that have historically used ozone depleting substances in their products:
- Refrigeration and air conditioning
- Fire extinguishing
Within these sectors, there are 50 independently modeled end uses. The model requires information on the market growth for each of the end uses, as well as a history of the market transition from ODS to alternatives. As ODS are phased out, a percentage of the market share originally filled by the ODS is allocated to each of its substitutes.
The Vintaging Model models the consumption of chemicals based on estimates of the quantity of equipment or products sold, serviced, and retired each year, and the amount of the chemical required to manufacture and/or maintain the equipment. It makes use of this market information to build an inventory of the in-use stocks of the equipment in each of the end uses. Emissions are estimated by applying annual leak rates, service emission rates, and disposal emission rates to each population of equipment.
By aggregating the emission and consumption output from the different end uses, the model produces estimates of total annual use and emissions of each chemical. For the purpose of projecting the use and emissions of chemicals into the future, the available information about probable evolutions of the end-use market is incorporated into the model.