What is a primary characteristic of Category IV appliances regarding efficiency?

A primary characteristic of Category IV appliances is their high efficiency with low emissions. These appliances are designed to operate with extremely high efficiency levels, often exceeding 90%, which means they convert a larger portion of fuel into usable energy compared to less efficient models. This high efficiency is complemented by low emissions, as the combustion process is more complete and minimizes waste products such as carbon monoxide and unburned hydrocarbons.

In addition to this, Category IV appliances typically utilize sealed combustion systems, drawing air from outside rather than from inside the building, which further reduces indoor air pollution and enhances safety. The combination of high efficiency and low emissions makes Category IV appliances a preferred choice for environmentally conscious consumers and those looking to minimize energy costs.