Whats a long term test? How long is it? What is the cost?
The EPA defines a long term test as one that runs for at least 90 days, and preferably for a full year. Ideally, the weather conditions should represent a balance of warm and cold weather, i.e. with an average outdoor temperature equal to the annual average. Click here for a handy test planner that will calculate the optimum “begin” and “end” dates for you.
